Graphs are propular to visualize a problem . Matrix representation is use to convert the graph in a form that used by the computer . This will help to get the efficent solution also provide a lots of mathematical equation .
This document is a project report submitted by S. Manikanta in partial fulfillment of the requirements for a Master of Science degree in Mathematics. The report discusses applications of graph theory. It provides an overview of graph theory concepts such as definitions of graphs, terminology used in graph theory, different types of graphs, trees and forests, graph isomorphism and operations, walks and paths in graphs, representations of graphs using matrices, applications of graphs in areas like computer science, fingerprint recognition, security, and more. The document also includes examples and illustrations to explain various graph theory concepts.
This document introduces some basic concepts in graph theory, including:
- A graph G is defined as a pair (V,E) where V is the set of vertices and E is the set of edges.
- Edges connect pairs of vertices and can be directed or undirected. Special types of edges include parallel edges and loops.
- Special graphs include simple graphs without parallel edges/loops, weighted graphs with numerical edge weights, and complete graphs where all vertex pairs are connected.
- Graphs can be represented by adjacency matrices and incidence matrices showing vertex-edge connections.
- Paths and cycles traverse vertices and edges, with Euler cycles passing through every edge once.
Graph Theory: Matrix representation of graphsAshikur Rahman
The document discusses different matrix representations of graphs:
1) Incidence matrices represent the relationship between vertices and edges, with each column having two 1s. Circuit matrices represent circuits, with each row as a circuit vector. Cut-set matrices represent edge sets whose removal disconnects the graph.
2) Path matrices represent paths between vertex pairs, with columns of all 0s/1s indicating edges not/in every path. Adjacency matrices directly encode vertex connectivity.
3) Exercises are provided to construct the incidence matrix, circuit matrix, fundamental circuit matrix, and cut-set matrix for a given graph.
This section provides an introduction to graphs and graph theory. Key points include:
- Graphs consist of vertices and edges that connect the vertices. They can be directed or undirected.
- Common terminology is introduced, such as adjacent vertices, neighborhoods, degrees of vertices, and handshaking theorem.
- Different types of graphs are discussed, including multigraphs, pseudographs, and directed graphs.
- Examples of graph models are given for computer networks, social networks, information networks, transportation networks, and software design. Graphs can be used to model many real-world systems and applications.
The document discusses different matrix representations of graphs:
1) Incidence matrix shows which edges are incident to each vertex with 1s and 0s.
2) Adjacency matrix shows which vertices are adjacent to each other with 1s and 0s.
3) Cut-set matrix shows which edges are part of given cut sets that disconnect the graph with 1s and 0s.
Graphs are a data structure composed of nodes connected by edges. There are two main types: directed graphs where edges show a flow between nodes, and undirected graphs where edges simply show a relationship between nodes. Key terminology includes adjacent nodes, paths, cyclic vs acyclic paths, and representations like adjacency matrices and lists. Graphs can model many real-world applications such as social networks, computer networks, road maps, and more.
The document defines and describes various graph concepts and data structures used to represent graphs. It defines a graph as a collection of nodes and edges, and distinguishes between directed and undirected graphs. It then describes common graph terminology like adjacent/incident nodes, subgraphs, paths, cycles, connected/strongly connected components, trees, and degrees. Finally, it discusses two common ways to represent graphs - the adjacency matrix and adjacency list representations, noting their storage requirements and ability to add/remove nodes.
This document is a project report submitted by S. Manikanta in partial fulfillment of the requirements for a Master of Science degree in Mathematics. The report discusses applications of graph theory. It provides an overview of graph theory concepts such as definitions of graphs, terminology used in graph theory, different types of graphs, trees and forests, graph isomorphism and operations, walks and paths in graphs, representations of graphs using matrices, applications of graphs in areas like computer science, fingerprint recognition, security, and more. The document also includes examples and illustrations to explain various graph theory concepts.
This document introduces some basic concepts in graph theory, including:
- A graph G is defined as a pair (V,E) where V is the set of vertices and E is the set of edges.
- Edges connect pairs of vertices and can be directed or undirected. Special types of edges include parallel edges and loops.
- Special graphs include simple graphs without parallel edges/loops, weighted graphs with numerical edge weights, and complete graphs where all vertex pairs are connected.
- Graphs can be represented by adjacency matrices and incidence matrices showing vertex-edge connections.
- Paths and cycles traverse vertices and edges, with Euler cycles passing through every edge once.
Graph Theory: Matrix representation of graphsAshikur Rahman
The document discusses different matrix representations of graphs:
1) Incidence matrices represent the relationship between vertices and edges, with each column having two 1s. Circuit matrices represent circuits, with each row as a circuit vector. Cut-set matrices represent edge sets whose removal disconnects the graph.
2) Path matrices represent paths between vertex pairs, with columns of all 0s/1s indicating edges not/in every path. Adjacency matrices directly encode vertex connectivity.
3) Exercises are provided to construct the incidence matrix, circuit matrix, fundamental circuit matrix, and cut-set matrix for a given graph.
This section provides an introduction to graphs and graph theory. Key points include:
- Graphs consist of vertices and edges that connect the vertices. They can be directed or undirected.
- Common terminology is introduced, such as adjacent vertices, neighborhoods, degrees of vertices, and handshaking theorem.
- Different types of graphs are discussed, including multigraphs, pseudographs, and directed graphs.
- Examples of graph models are given for computer networks, social networks, information networks, transportation networks, and software design. Graphs can be used to model many real-world systems and applications.
The document discusses different matrix representations of graphs:
1) Incidence matrix shows which edges are incident to each vertex with 1s and 0s.
2) Adjacency matrix shows which vertices are adjacent to each other with 1s and 0s.
3) Cut-set matrix shows which edges are part of given cut sets that disconnect the graph with 1s and 0s.
Graphs are a data structure composed of nodes connected by edges. There are two main types: directed graphs where edges show a flow between nodes, and undirected graphs where edges simply show a relationship between nodes. Key terminology includes adjacent nodes, paths, cyclic vs acyclic paths, and representations like adjacency matrices and lists. Graphs can model many real-world applications such as social networks, computer networks, road maps, and more.
The document defines and describes various graph concepts and data structures used to represent graphs. It defines a graph as a collection of nodes and edges, and distinguishes between directed and undirected graphs. It then describes common graph terminology like adjacent/incident nodes, subgraphs, paths, cycles, connected/strongly connected components, trees, and degrees. Finally, it discusses two common ways to represent graphs - the adjacency matrix and adjacency list representations, noting their storage requirements and ability to add/remove nodes.
In mathematics, graph theory is the study of graphs, which are mathematical structures used to model pairwise relations between objects.Graph theory is also important in real life.
This document provides an overview of graph theory, including its history and key concepts. It defines a graph as a set of nodes connected by edges. Important early contributors are noted, such as Euler's work on the Seven Bridges of Königsberg problem. Exact definitions of graph types like simple, directed, and weighted graphs are given. Key graph concepts explained in less than three sentences include connectivity, degree, paths, cycles, and trees. The document also briefly discusses representing graphs through adjacency lists and matrices. It concludes by thanking the reader and listing references.
This document defines and provides examples of graphs and their representations. It discusses:
- Graphs are data structures consisting of nodes and edges connecting nodes.
- Examples of directed and undirected graphs are given.
- Graphs can be represented using adjacency matrices or adjacency lists. Adjacency matrices store connections in a grid and adjacency lists store connections as linked lists.
- Key graph terms are defined such as vertices, edges, paths, and degrees. Properties like connectivity and completeness are also discussed.
The document discusses various graph theory concepts including:
- Types of graphs such as simple graphs, multigraphs, pseudographs, directed graphs, and directed multigraphs which differ based on allowed edge connections.
- Graph terminology including vertices, edges, degrees, adjacency, incidence, paths, cycles, and representations using adjacency lists and matrices.
- Weighted graphs and algorithms for finding shortest paths such as Dijkstra's algorithm.
- Euler and Hamilton paths/circuits and conditions for their existence.
- The traveling salesman problem of finding the shortest circuit visiting all vertices.
This document discusses graph data structures and algorithms. A graph consists of nodes and edges, where nodes represent entities and edges represent relationships between nodes. There are different types of graphs including undirected, directed, weighted, and cyclic graphs. Graphs can be represented using an adjacency matrix or adjacency list. Graphs are used to model real-world networks and solve problems in areas like social networks, maps, robot path planning, and neural networks.
The document defines and provides examples of Hasse diagrams. A Hasse diagram is a type of graph used to represent partially ordered sets. It draws elements with edges between them if one element covers another. The document gives an example Hasse diagram and explains that it shows the relations between elements in a partially ordered set with edges between elements if one is directly above the other in the order.
The document discusses submatrices of circuit matrices and their properties. Some key points:
- A subgraph's incidence matrix is a submatrix of the original graph's incidence matrix.
- An (n-1)x(n-1) submatrix of a connected graph's incidence matrix is nonsingular if and only if the corresponding edges form a spanning tree.
- A circuit matrix represents cycles in a graph, with 1s indicating which edges are in each cycle.
- The circuit and incidence matrices of a graph have orthogonal rows, meaning their row dot products are all 0.
- A fundamental circuit matrix contains a basis of fundamental cycles, and has an identity submatrix, indicating its rank equals
The document discusses graph theory and provides definitions and examples of various graph concepts. It defines what a graph is consisting of vertices and edges. It also defines different types of graphs such as simple graphs, multigraphs, digraphs and provides examples. It discusses graph terminology, models, degree of graphs, handshaking lemma, special graphs and applications. It also provides explanations of planar graphs, Euler's formula and graph coloring.
The document discusses asymptotic notations that are used to describe the time complexity of algorithms. It introduces big O notation, which describes asymptotic upper bounds, big Omega notation for lower bounds, and big Theta notation for tight bounds. Common time complexities are described such as O(1) for constant time, O(log N) for logarithmic time, and O(N^2) for quadratic time. The notations allow analyzing how efficiently algorithms use resources like time and space as the input size increases.
The document provides an introduction to graph theory. It begins with a brief history, noting that graph theory originated from Euler's work on the Konigsberg bridges problem in 1735. It then discusses basic concepts such as graphs being collections of nodes and edges, different types of graphs like directed and undirected graphs. Key graph theory terms are defined such as vertices, edges, degree, walks, paths, cycles and shortest paths. Different graph representations like the adjacency matrix, incidence matrix and adjacency lists are also introduced. The document is intended to provide an overview of fundamental graph theory concepts.
This document provides definitions and theorems related to graph theory. It begins with definitions of simple graphs, vertices, edges, degree, and the handshaking lemma. It then covers definitions and properties of paths, cycles, adjacency matrices, connectedness, Euler paths and circuits. The document also discusses Hamilton paths, planar graphs, trees, and other special types of graphs like complete graphs and bipartite graphs. It provides examples and proofs of many graph theory concepts and results.
This document provides an introduction to graph theory concepts. It defines what a graph is consisting of vertices and edges. It discusses different types of graphs like simple graphs, multigraphs, digraphs and their properties. It introduces concepts like degrees of vertices, handshaking lemma, planar graphs, Euler's formula, bipartite graphs and graph coloring. It provides examples of special graphs like complete graphs, cycles, wheels and hypercubes. It discusses applications of graphs in areas like job assignments and local area networks. The document also summarizes theorems regarding planar graphs like Kuratowski's theorem stating conditions for a graph to be non-planar.
Graph theory is widely used in science and everyday life. It can model real world problems and systems using vertices to represent objects and edges to represent connections between objects. The document discusses several applications of graph theory in chemistry, physics, biology, computer science, operations research, Google Maps, and the internet. For example, in chemistry graph theory is used to model molecules with atoms as vertices and bonds as edges. In computer science, graph theory concepts are used to develop algorithms for problems like finding shortest paths in a network.
Graph theory is the study of graphs, which are mathematical structures used to model pairwise relationships between objects. A graph consists of vertices and edges that connect the vertices. Graph theory is used in computer science to model problems that can be represented as networks, such as determining routes in a city or designing circuits. It allows analyzing properties of graphs like connectivity and determining the minimum number of resources required. A graph can be represented using an adjacency matrix or adjacency list to store information about its vertices and edges.
The document discusses graphs and their applications. It defines key graph terms like vertices, edges, directed/undirected graphs, paths, cycles, etc. It then describes algorithms for finding minimum spanning trees, Eulerian cycles, Hamiltonian paths, and approximations for the traveling salesman problem. Examples are provided to illustrate minimum spanning tree and Christofide's algorithms for TSP.
Graph theory has many applications including social networks, data organization, and communication networks. The document discusses Dijkstra's algorithm for finding the shortest path between nodes in a graph and its application to finding shortest routes between cities. It also discusses using graph representations for fingerprint classification, where fingerprints are modeled as graphs with nodes for fingerprint regions and edges between adjacent regions. Fingerprints are classified based on the structure of these graphs and compared to model graphs for matching.
The document provides an introduction to graph theory. It lists prescribed and recommended books, outlines topics that will be covered including history, definitions, types of graphs, terminology, representation, subgraphs, connectivity, and applications. It notes that the Government of India designated June 10th as Graph Theory Day in recognition of the influence and importance of graph theory.
Matrices are used extensively in computer applications related to graphics and image processing. Matrices represent images as a collection of coordinate points, and changing the values in the matrix allows images to be transformed through operations like scaling, rotation, and distortion. Matrices are also used to encrypt and decrypt codes and messages. Overall, matrices play a vital role in computer applications by enabling graphical representations and transformations that would otherwise be very complicated to achieve.
The document discusses graphs and graph theory. It defines graphs as non-linear data structures used to model networks and relationships. The key types of graphs are undirected graphs, where edges have no orientation, and directed graphs, where edges have orientation. Graph traversal algorithms like depth-first search and breadth-first search are discussed. Common graph terminology is defined, including vertices, edges, paths, cycles, degrees. Different graph representations like adjacency matrices and adjacency lists are also covered. Applications of graphs include modeling networks, routes, and relationships.
1) Graph theory concepts such as undirected graphs, directed graphs, weighted graphs, mixed graphs, simple graphs, multigraphs, and pseudographs are introduced. Common graph terminology like vertices, edges, loops, degrees, adjacency and connectivity are defined.
2) Different types of graphs are discussed including trees, forests, cycles, wheels, complete graphs, bipartite graphs, and n-cubes. Matrix representations using adjacency matrices are also covered.
3) The document touches on graph isomorphism, Eulerian graphs, Hamiltonian graphs, and algorithms for determining graph properties like connectivity and number of components.
In mathematics, graph theory is the study of graphs, which are mathematical structures used to model pairwise relations between objects.Graph theory is also important in real life.
This document provides an overview of graph theory, including its history and key concepts. It defines a graph as a set of nodes connected by edges. Important early contributors are noted, such as Euler's work on the Seven Bridges of Königsberg problem. Exact definitions of graph types like simple, directed, and weighted graphs are given. Key graph concepts explained in less than three sentences include connectivity, degree, paths, cycles, and trees. The document also briefly discusses representing graphs through adjacency lists and matrices. It concludes by thanking the reader and listing references.
This document defines and provides examples of graphs and their representations. It discusses:
- Graphs are data structures consisting of nodes and edges connecting nodes.
- Examples of directed and undirected graphs are given.
- Graphs can be represented using adjacency matrices or adjacency lists. Adjacency matrices store connections in a grid and adjacency lists store connections as linked lists.
- Key graph terms are defined such as vertices, edges, paths, and degrees. Properties like connectivity and completeness are also discussed.
The document discusses various graph theory concepts including:
- Types of graphs such as simple graphs, multigraphs, pseudographs, directed graphs, and directed multigraphs which differ based on allowed edge connections.
- Graph terminology including vertices, edges, degrees, adjacency, incidence, paths, cycles, and representations using adjacency lists and matrices.
- Weighted graphs and algorithms for finding shortest paths such as Dijkstra's algorithm.
- Euler and Hamilton paths/circuits and conditions for their existence.
- The traveling salesman problem of finding the shortest circuit visiting all vertices.
This document discusses graph data structures and algorithms. A graph consists of nodes and edges, where nodes represent entities and edges represent relationships between nodes. There are different types of graphs including undirected, directed, weighted, and cyclic graphs. Graphs can be represented using an adjacency matrix or adjacency list. Graphs are used to model real-world networks and solve problems in areas like social networks, maps, robot path planning, and neural networks.
The document defines and provides examples of Hasse diagrams. A Hasse diagram is a type of graph used to represent partially ordered sets. It draws elements with edges between them if one element covers another. The document gives an example Hasse diagram and explains that it shows the relations between elements in a partially ordered set with edges between elements if one is directly above the other in the order.
The document discusses submatrices of circuit matrices and their properties. Some key points:
- A subgraph's incidence matrix is a submatrix of the original graph's incidence matrix.
- An (n-1)x(n-1) submatrix of a connected graph's incidence matrix is nonsingular if and only if the corresponding edges form a spanning tree.
- A circuit matrix represents cycles in a graph, with 1s indicating which edges are in each cycle.
- The circuit and incidence matrices of a graph have orthogonal rows, meaning their row dot products are all 0.
- A fundamental circuit matrix contains a basis of fundamental cycles, and has an identity submatrix, indicating its rank equals
The document discusses graph theory and provides definitions and examples of various graph concepts. It defines what a graph is consisting of vertices and edges. It also defines different types of graphs such as simple graphs, multigraphs, digraphs and provides examples. It discusses graph terminology, models, degree of graphs, handshaking lemma, special graphs and applications. It also provides explanations of planar graphs, Euler's formula and graph coloring.
The document discusses asymptotic notations that are used to describe the time complexity of algorithms. It introduces big O notation, which describes asymptotic upper bounds, big Omega notation for lower bounds, and big Theta notation for tight bounds. Common time complexities are described such as O(1) for constant time, O(log N) for logarithmic time, and O(N^2) for quadratic time. The notations allow analyzing how efficiently algorithms use resources like time and space as the input size increases.
The document provides an introduction to graph theory. It begins with a brief history, noting that graph theory originated from Euler's work on the Konigsberg bridges problem in 1735. It then discusses basic concepts such as graphs being collections of nodes and edges, different types of graphs like directed and undirected graphs. Key graph theory terms are defined such as vertices, edges, degree, walks, paths, cycles and shortest paths. Different graph representations like the adjacency matrix, incidence matrix and adjacency lists are also introduced. The document is intended to provide an overview of fundamental graph theory concepts.
This document provides definitions and theorems related to graph theory. It begins with definitions of simple graphs, vertices, edges, degree, and the handshaking lemma. It then covers definitions and properties of paths, cycles, adjacency matrices, connectedness, Euler paths and circuits. The document also discusses Hamilton paths, planar graphs, trees, and other special types of graphs like complete graphs and bipartite graphs. It provides examples and proofs of many graph theory concepts and results.
This document provides an introduction to graph theory concepts. It defines what a graph is consisting of vertices and edges. It discusses different types of graphs like simple graphs, multigraphs, digraphs and their properties. It introduces concepts like degrees of vertices, handshaking lemma, planar graphs, Euler's formula, bipartite graphs and graph coloring. It provides examples of special graphs like complete graphs, cycles, wheels and hypercubes. It discusses applications of graphs in areas like job assignments and local area networks. The document also summarizes theorems regarding planar graphs like Kuratowski's theorem stating conditions for a graph to be non-planar.
Graph theory is widely used in science and everyday life. It can model real world problems and systems using vertices to represent objects and edges to represent connections between objects. The document discusses several applications of graph theory in chemistry, physics, biology, computer science, operations research, Google Maps, and the internet. For example, in chemistry graph theory is used to model molecules with atoms as vertices and bonds as edges. In computer science, graph theory concepts are used to develop algorithms for problems like finding shortest paths in a network.
Graph theory is the study of graphs, which are mathematical structures used to model pairwise relationships between objects. A graph consists of vertices and edges that connect the vertices. Graph theory is used in computer science to model problems that can be represented as networks, such as determining routes in a city or designing circuits. It allows analyzing properties of graphs like connectivity and determining the minimum number of resources required. A graph can be represented using an adjacency matrix or adjacency list to store information about its vertices and edges.
The document discusses graphs and their applications. It defines key graph terms like vertices, edges, directed/undirected graphs, paths, cycles, etc. It then describes algorithms for finding minimum spanning trees, Eulerian cycles, Hamiltonian paths, and approximations for the traveling salesman problem. Examples are provided to illustrate minimum spanning tree and Christofide's algorithms for TSP.
Graph theory has many applications including social networks, data organization, and communication networks. The document discusses Dijkstra's algorithm for finding the shortest path between nodes in a graph and its application to finding shortest routes between cities. It also discusses using graph representations for fingerprint classification, where fingerprints are modeled as graphs with nodes for fingerprint regions and edges between adjacent regions. Fingerprints are classified based on the structure of these graphs and compared to model graphs for matching.
The document provides an introduction to graph theory. It lists prescribed and recommended books, outlines topics that will be covered including history, definitions, types of graphs, terminology, representation, subgraphs, connectivity, and applications. It notes that the Government of India designated June 10th as Graph Theory Day in recognition of the influence and importance of graph theory.
Matrices are used extensively in computer applications related to graphics and image processing. Matrices represent images as a collection of coordinate points, and changing the values in the matrix allows images to be transformed through operations like scaling, rotation, and distortion. Matrices are also used to encrypt and decrypt codes and messages. Overall, matrices play a vital role in computer applications by enabling graphical representations and transformations that would otherwise be very complicated to achieve.
The document discusses graphs and graph theory. It defines graphs as non-linear data structures used to model networks and relationships. The key types of graphs are undirected graphs, where edges have no orientation, and directed graphs, where edges have orientation. Graph traversal algorithms like depth-first search and breadth-first search are discussed. Common graph terminology is defined, including vertices, edges, paths, cycles, degrees. Different graph representations like adjacency matrices and adjacency lists are also covered. Applications of graphs include modeling networks, routes, and relationships.
1) Graph theory concepts such as undirected graphs, directed graphs, weighted graphs, mixed graphs, simple graphs, multigraphs, and pseudographs are introduced. Common graph terminology like vertices, edges, loops, degrees, adjacency and connectivity are defined.
2) Different types of graphs are discussed including trees, forests, cycles, wheels, complete graphs, bipartite graphs, and n-cubes. Matrix representations using adjacency matrices are also covered.
3) The document touches on graph isomorphism, Eulerian graphs, Hamiltonian graphs, and algorithms for determining graph properties like connectivity and number of components.
Graphs can be represented using adjacency matrices or adjacency lists. Common graph operations include traversal algorithms like depth-first search (DFS) and breadth-first search (BFS). DFS traverses a graph in a depth-wise manner similar to pre-order tree traversal, while BFS traverses in a level-wise or breadth-first manner similar to level-order tree traversal. The document also discusses graph definitions, terminologies, representations, elementary graph operations, and traversal methods like DFS and BFS.
This document provides an introduction to graph theory through a presentation on the topic. It defines what a graph is by explaining that a graph G consists of a set of vertices V and edges E. It then gives examples and defines basic terminology like adjacency and incidence. The document also covers topics like degrees of vertices, regular and bipartite graphs, and representations of graphs through adjacency and incidence matrices.
The document defines graphs and discusses different types of graphs and graph representations. It begins by defining what a graph is - a set of vertices and edges. It describes directed vs undirected graphs. It then discusses different graph representations including adjacency matrices and adjacency lists. It also covers graph operations and concepts such as degree, traversal methods like depth-first search and breadth-first search, connected components, spanning trees, and minimum cost spanning trees.
This document contains definitions and explanations of various graph theory terms in the form of 26 multiple choice questions. Some key terms defined and explained include: graph, simple graph, connected graph, components, tree, rooted tree, binary tree, walk, path, circuit, degree, adjacency, incidence, isomorphism, subgraph, Euler graph, and Hamiltonian path. Examples are provided to illustrate many of the graph theory concepts discussed.
This document contains 26 multiple choice questions and their answers related to graph theory. It begins by defining key graph theory terms like graphs, vertices, edges, simple graphs, and applications of graph theory. It then discusses incidence, adjacency, degrees, finite and infinite graphs, isolated and pendant vertices, null graphs, and multigraphs. The document also defines complete graphs, regular graphs, cycles, isomorphism, subgraphs, walks, paths, circuits, connectivity, components, Euler graphs, Hamiltonian circuits/paths, trees, properties of trees, distance in trees, eccentricity, center, distance metric, radius, diameter, rooted trees, and binary rooted trees.
Graph theory is the study of graphs, which are mathematical structures used to model pairwise relations between objects. A graph consists of vertices and edges connecting pairs of vertices. There are many types of graphs including trees, which are connected acyclic graphs. Spanning trees are subgraphs of a graph that connect all vertices using the minimum number of edges. Key concepts in graph theory include paths, connectedness, cycles, and isomorphism between graphs.
The document defines and provides examples of graphs, including undirected and directed graphs. It discusses graph representations using adjacency matrices and adjacency lists. It also covers graph terminology like vertices, edges, paths, cycles, and connected components. Finally, it mentions some common graph operations like traversal using depth-first search and breadth-first search.
This document provides an introduction to graph theory, including basic terminology and concepts. It defines what a graph is mathematically as a collection of vertices and edges. It describes different types of graphs such as simple graphs, multiple graphs, weighted graphs, finite and infinite graphs, labeled graphs, and directed graphs. It also defines graph theory terms like adjacency, incidence, degree of a vertex, isomorphism, subgraphs, and graph operations like union and intersection. The document provides examples to illustrate each term and concept.
This document provides an introduction to graph theory, including basic terminology and concepts. It defines what a graph is mathematically as a collection of vertices and edges. It describes different types of graphs such as simple graphs, multiple graphs, weighted graphs, finite and infinite graphs, labeled graphs, and directed graphs. It also defines graph theory terms like adjacency, incidence, degree of a vertex, isomorphism, subgraphs, and graph operations like union and intersection. The document provides examples to illustrate each term and concept.
This document defines graphs and discusses various graph representations and operations. It defines graphs as consisting of vertices and edges. Common graph representations include adjacency matrices and adjacency lists. Adjacency matrices store connectivity information in a 2D array while adjacency lists use linked data structures. The document provides examples and discusses operations like finding the degree of vertices, traversing graphs via depth-first and breadth-first search, and identifying connected components and spanning trees.
This document defines graphs and discusses various graph representations and operations. It defines graphs as consisting of vertices and edges. Common graph representations include adjacency matrices and adjacency lists. Adjacency matrices store connectivity information in a 2D array while adjacency lists use linked data structures. The document discusses traversing graphs using depth-first and breadth-first search and finding connected components and spanning trees.
This document defines key graph terminology and concepts. It begins by defining what a graph is composed of - vertices and edges. It then discusses directed vs undirected graphs and defines common graph terms like adjacent vertices, paths, cycles, and more. The document also covers different ways to represent graphs, such as adjacency matrices and adjacency lists. Finally, it briefly introduces common graph search methods like breadth-first search and depth-first search.
A graph G consists of a non empty set V called the set of nodes (points, vertices) of the graph, a set E, which is the set of edges of the graph and a mapping from the set of edges E to a pair of elements of V.
Any two nodes, which are connected by an edge in a graph are called "adjacent nodes".
In a graph G(V,E) an edge which is directed from one node to another is called a "directed edge", while an edge which has no specific direction is called an "undirected edge". A graph in which every edge is directed is called a "directed graph" or a "digraph". A graph in which every edge is undirected is called an "undirected graph".
If some of edges are directed and some are undirected in a graph then the graph is called a "mixed graph".
Any graph which contains some parallel edges is called a "multigraph".
If there is no more than one edge but a pair of nodes then, such a graph is called "simple graph."
A graph in which weights are assigned to every edge is called a "weighted graph".
In a graph, a node which is not adjacent to any other node is called "isolated node".
A graph containing only isolated nodes is called a "null graph". In a directed graph for any node v the number of edges which have v as initial node is called the "outdegree" of the node v. The number of edges to have v as their terminal node is called the "Indegree" of v and Sum of outdegree and indegree of a node v is called its total degree.
CS-102 Data Structure lectures on Graphsssuser034ce1
The document defines and explains various graph concepts:
- It describes graph representations like adjacency matrices and lists, and types of graphs like undirected, directed, and weighted.
- Key graph terminology is introduced such as vertices, edges, paths, cycles, connectedness, subgraphs, and degrees of vertices.
- Examples are provided to illustrate concepts like complete graphs, trees, and bipartite graphs.
- Graph representations like adjacency matrices and linked/packed adjacency lists are also summarized.
CS-102 Data Structure lectures on Graphsssuser034ce1
The document defines and explains various graph concepts:
- It describes graph representations like adjacency matrices and lists, and types of graphs like undirected, directed, and weighted.
- Key graph terminology is introduced such as vertices, edges, paths, cycles, connectedness, subgraphs, and degrees of vertices.
- Examples are provided to illustrate concepts like complete graphs, trees, and bipartite graphs.
- Graph representations like adjacency matrices and linked/packed adjacency lists are also summarized.
Graph theory concepts complex networks presents-rouhollah nabatinabati
This document provides an introduction to network and social network analysis theory, including basic concepts of graph theory and network structures. It defines what a network and graph are, explains what network theory techniques are used for, and gives examples of real-world networks that can be represented as graphs. It also summarizes key graph theory concepts such as nodes, edges, walks, paths, cycles, connectedness, degree, and centrality measures.
This document defines and provides examples of graphs and graph representations. It begins by discussing Euler's use of graphs to solve the Königsberg bridge problem. It then defines graphs formally as G=(V,E) with vertices V and edges E. Examples of undirected and directed graphs are given. Common graph terms like paths, cycles, and connectivity are defined. Methods of representing graphs through adjacency matrices and adjacency lists are described and examples are provided. Finally, the document briefly discusses graph traversal algorithms and the concept of weighted edges.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Strategies for Effective Upskilling is a presentation by Chinwendu Peace in a Your Skill Boost Masterclass organisation by the Excellence Foundation for South Sudan on 08th and 09th June 2024 from 1 PM to 3 PM on each day.
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
MATATAG CURRICULUM: ASSESSING THE READINESS OF ELEM. PUBLIC SCHOOL TEACHERS I...NelTorrente
In this research, it concludes that while the readiness of teachers in Caloocan City to implement the MATATAG Curriculum is generally positive, targeted efforts in professional development, resource distribution, support networks, and comprehensive preparation can address the existing gaps and ensure successful curriculum implementation.
3. Graph is a set of some dots (known as Vertex ) and some line
which connect those dots (knows as Edge)
The basic need of graph a better understanding , broader
meaning and easy to grab complexity
So we use Graphs to visually illustrate relationships in the data
This need further complicated
Graph stands as backbone of many real world problem
Such as network flow problem
4. Situation comes where we need a better way out to convert
the graphical notation into digital or algorithmic format
This need creates the area of this topic . { MATRIX
REPRESENTAION OF GRAPH } .
The mechanism of this representation should be effective ,
efficient and easy to use
Because we are all face a problem of limited resources
5. The general idea is that the visual graph can’t be used in a
system for work
The increasing no of complexity can not anymore operable
with pen and paper manner
The demand of graph in various sector
Various operation performed on the graph
Want a efficient output quickly
6. As matrix is widely used in mechanical manipulations
Also it has efficient to define operation with various
operators
Various previously solved properties also helps a lot
Most important , Matrix is convenient for defining graph
So this chapter is all about
Formation of matrix
Different kind of observation on that matrix
7. Some general properties should be kept in mind .
Followings are the terms that we will carry out in the
whole presentation
So its good to remember those things :
1) Incidence
2) Adjacent
3) Degree
4) Walk ,Path , Circuit
5) Fundamental Circuit
6) Cut set
7) Spanning tree
8) Rank and Nullity
9) Ring Sum operation
10) Isomorphism
8. Each edge has two end points / vertex (Self loop
contains one).
For ex , E1 as two end points {A,B} . There A and
B are called INCIDENT with respect to E1 edge
.
A B
C D
E1
E2
E3
E4
E5
E6
Two end points of an edge are called ADJACENT to each other
For ex , node A and D are said to adjacent
The total count of incident , is known as DEGREE of a graph (Self loop
counts 2 )
For ex , Degree(A) = 3 and Degree(B)=4
IN A GRAPH , WE USE :
V- VERTEX SET ; E – EDGE
SET
9. While traversing a graph , walk is
An alternating sequence of vertex and edge ;
Edge repetition is not allowed
For ex , A-E2-C-E4-D-E5-A-E1-B
Path is a type of open walk
Vertex repetition is not allowed
For ex , A-E2-C-E4-D
Circuit is a kind of closed walk
Node repetition is allowed for only start node
For ex , A-E2-C-E4-D-E5-A
A B
C D
E1
E2
E3
E4
E5
E6
10. In a connected graph G , Spanning tree is a subgraph
Which contains all vertices of G
Gives a minimal edge connected subgraph
Edges of the spanning tree , called Branch
Others are known as Chord .
For ex , G” is a spanning tree .
Brunch = n-1 = 4-1=3
Chord = e-n+1= 6-4+1 = 3
Chords equipped a interesting property
A B
C D
E1
E2
E3
E4
E5
E6
A B
C D
E3
E4
E1
G
G”
11. With a given Spanning tree and its chord .
A circuit formed ,introducing every single chord .
Those circuits are known as Fundamental circuits .
For ex , Spanning tree of the graph is -
E4
E5
E6
E3
E2
E1
E7
E1
G
G”
Now G” is spanning tree of G
In G :– v = 5 , e =7
In G”: – v = 5 ,
Brunch = 4 & Chord = 3
Chords are { E3 , E6 , E2 }
13. Those two term comes from general
observations
The no of component ‘k’ never cross ‘n’
So , n ≥ 𝑘
Rank = n-k
Another , The no of edge ‘e’ is never
less than ‘n’
So e ≥ n = e ≥ n - k
Here , Nullity = e – n + k
For ex , for the above graph ‘G’
Rank = 4-2=2
Nullity = 4-4+2 = 2
Think , For connected Graph
Rank = Branch and Nullity = Chord
So , Total edge = Rank + Nullity
A B
C D
E1
E2
E3
E4
G
E
F
14. It’s a set which contains edge , such that
Whose removal make the graph disconnected
Also point that the set must be minimal
So, no further sub-set obtain from the cut set
In the ex , set {E1 , E5 , E6 , E3} is a cut set ,
Observed that no proper subset is Cut set .
A
D
E
C
B
E1
E2
E3
E4
E5
E6
E7
E8
15. Drawing of the graph is not fix
So , there are multiple view of a single graph
Need rules for detect two same graph
If match found , two are called Isomorphic
Two graphs are isomorphism , if
No of edge in both graph same
No of vertex same
Adjacency relation holds
For ex , Following two are isomorphic in nature .
16. A graph operation act as follows :
Let G1 G2 be two graph , with {V1,E1} , {V2,E2} respectively
Then G3 = Ring_Sum(G1,G2) ,As
V3 = V1 ∪ V2
E3 = Either in E1 or in E2 , but not in both
For ex ,
A
B
A
E
D
C
B
D F
C
E1 E2
E3 E4
E5
E2E1
A
B C
D
E
FG1 G2
G3
m
17.
18. With a given graph G , Adjacency or connection matrix is a n by n
symmetric binary matrix .
Consider graph has no parallel edge and self loop , because those
are not carry redundant information .
Then each element of the graph define as ,
Xi,j = 1 if ith and jth vertex are end point of an edge .
Else = 0
19. A
D
E
C
B
0 1 0 1 1
1 0 1 0 1
0 1 0 1 0
1 0 1 0 1
1 1 0 1 0
A
B
C
D
E
A B C D
E
20. All entity in principal diagonal is 0 , iff the graph has no self
loop
A
D
E
C
B
0 1 0 1 1
1 0 1 0 1
0 1 0 1 0
1 0 1 0 1
1 1 0 1 0
A
B
C
D
E
A B C D
E
21. A graph with no parallel edge and self loop
In its adjacent matrix , degree of a vertex define by no of 1 in row or
column .
A
D
E
C
B
0 1 0 1 1
1 0 1 0 1
0 1 0 1 0
1 0 1 0 1
1 1 0 1 0
A
B
C
D
E
A B C D
E
Degree of A - 3
22. Permutation of any two row and equivalent column gives us Two
isomorphic graph
0 1 1 0
1 0 1 0
1 1 0 1
0 0 1 0
A B C D
A
B
C
D
0 0 1 1
1 0 1 0
1 1 0 1
0 0 1 0
A B C D
A
B
C
D
A
DC
B
23. 0 0 1 1
1 0 1 0
1 1 0 1
0 0 1 0
A B C D
A
B
C
D
0 0 1 1
0 0 1 0
1 1 0 1
1 0 1 0
A B C D
A
B
C
D
A
DC
B
25. Let G be a disconnected graph
g1 and g2 be two component
The adjacency matrix A partitioned as follows :
X(G) =
X(g1)
X(g2)0
0
Where X(g1) and X(g2) are adjacent matrix of component g1 and g2
respectively
26. A
G
FE
CD
B
0 1 0 1 0 0 0
1 0 1 0 0 0 0
0 1 0 1 0 0 0
1 0 1 0 0 0 0
0 0 0 0 0 1 1
0 0 0 0 1 0 1
0 0 0 0 1 0 1
A
B
C
D
E
F
G
A B C D E F G
28. Let G be a graph with n vertices and e edges. And there is no self-loop.
The incidence matrix A (G) is an v × e matrix= [a i j ]
Whose n rows correspond to the v vertices and e columns correspond to the e
edges
The Matrix element , a i j =1 ,if edge e j is incident on vertices vi
=0 , otherwise
Incidence Matrix
34. 5. If a graph is disconnected and consists of two components
g1and g2 the incidence matrix A(G) of graph G can be written
in a block diagonal form as
A(G)
A(g1)
0
0
A(g2)
Where A(g1) and A(g2) are the incidence matrices of components g1 and g2. This
observation results the fact that no edge in g1 incident on vertices of g2 ,and vice versa
Obviously this remarks is also true for a disconnected graph with any number of
components.
Take an example to understand this property
36. 6.Permutation of any two rows or columns in an incidence matrix simply
corresponds to relabelling the vertices and edges of the same graph
v1
v3
v2
e3
e2
e1
e1 e2 e3
V1
V2
V3
1 0
1
1 1 0
0 1
1
e1 e2 e3
V3
V2
V1
0 1 1
1 1 0
1 0 1
37. Path Matrix
A path matrix is defined for a specific pair of vertices in a graph ,say (x , y)
And is written as P(x ,y).
And The rows in P(x,y) correspond the different paths between vertices x & y and
columns correspond to the edges in G.
The path matrix for (x,y) vertices is P(x,y)=[pij ]
Pij = 1 if jth edge lies in ith path
= 0 , otherwise.
39. OBSERVATIONS
1. A column of all zeros corresponds to an edge that does not lie in any path between
x and y.
v1
v3
v2
v4
e1
e2
e4
e3
e5
v5 e1 e2 e3 e4 e5
e6
1 1 1 0 0 0
0
0 0 0 0 1
0
0 0 1 1 0
0
P(v1 ,v3 )
2
3
e6
40. 2. A column of all ones corresponds to an edge that lies in every path between x
and y.
v1
v3
v2
v4
e1
e2
e4
e3
e5
v5
e1 e2 e3 e4 e5 e6
1 1 1 0 0 0
1
0 0 0 0 1
1
0 0 1 1 0
1
P(v5 ,v3 )
2
3
e6
41. 3. There is no row with all zeros.
v1
v3
v2
v4
e1
e2
e4
e3
e5
v5
e1 e2 e3 e4 e5 e6
1 1 1 0 0 0
1
0 0 0 0 1
1
0 0 1 1 0
1
P(v5 ,v3 )
2
3
e6
There is no edge in that path. But it
is not possible to make path without
any edge
42. 4. The ring sum of any two rows in P(x, y) corresponds to a circuit
v1
v3
v2
v4
e1
e2
e4
e3
e5
v5
e1 e2 e3 e4 e5 e6
1 1 1 0 0 0
1
0 0 0 0 1
1
0 0 1 1 0
1
P(v5 ,v3 )
2
3
e6
1 3
v1
v3
v2
v4
e1
e2
e4
e3
e1
1
e2
1
e3
1
e4
1
e5
0
e6
0
43. Journey of life is a Circuit , two path to archive the
Goal . Choose wisely . ( Part 3 begins …)
44. Like adjacency or incident matrix , it is an another way
of representing a graph.
It is a circuit x edge matrix .From this matrix we can
identify which edge is belonged to which circuit of a graph
Formal defination:- Let q be the total number of circuits of graph
G(V,E) and the number of edges in G is e . Then the circuit matrix
of the graph G , B(G) =[bi j ] is a q x e matrix defined as
follows
bi j =1 , if ith circuit includes jth edge , and
=0 ,otherwise
48. circuit
matrix
4. The number of 1's in a row is equal to the number of edges in the
corresponding circuit.
e1
e2
e3
e4
e5
e6
G(V,E)
e4 e6e1 e2 e3 e5
(e1 e2 e3 )
0 0 1 1 1
1
( e3 e4 e5 e6 )
1 1 1 0 0 0
1
B(G) (Circuit matrix of G )
( e1e2 e4 e5
e6) 0 11 11
49. circuit
matrix
4. If graph G is separable (or disconnected) and consists of two blocks (or
components) g1 and g2 , then circuit matrix B(G) can be written in a block-
diagonal form as
where B(g1) and B(g2) are the circuit matrices of g1 and g2.
This observation results from the fact that the circuits in g1 have no edges belonging to g2
and vice versa.
Take an example to understand this property in better way
53. circuit matrix
Relationship between Incident matrix (A) and circuit
matrix (B) of a self-loop free graph G
● Let A and B be ,respectively ,the circuit matrix and the incident matrix (of a self-loop free
graph) whose columns are arranged using same order of edges. Then every row of A orthogonal
to every row of B ; That is
A . BT = B . AT = 0 (mod 2)
e1
e2
e3
e4
e5
e6
G(V,E)
e1 e2 e3 e4 e5 e6
V1
V2
V3
V4
V5
1 1 0 0 0 0
0 1 1 1 0 0
0 0 0 1 1 0
0 0 0 0 1 1
1 0 1 0 O
1
V1
V2
V3
V4 V5
e4 e6e1 e2 e3 e5
(e1 e2 e3 )
0 0 1 1 1 1( e3 e4 e5 e6 )
1 1 1 0 0 0
1 1 0 1 1 1
B(G) (Circuit matrix of G )
(e1 e2 e4 e5 e6 )
A(G)( Incidence matrix of G)
55. Now, if we know only the fundamental circuits of a graph ,then we
easily find out all other non –fundamental circuits by applying ring
sums( i.e. linear combinations) of those fundamental circuits .
Rank of a matrix:- Rank of a matrix in defined as the order of largest
square matrix whose determinate is not zero
Fundamental circuit matrix (Bf):- A sub-matrix (of a circuit matrix ,B) in which all rows
correspond to a set of all fundamental circuits.
● It is a (e-n+k)(fundamental circuit or chord) by e matrix as total chord is (e-n+k) and each
chord make a fundamental circuit.
●As in matrix B, permutations of rows (and/or of columns) of Bf do not affect
57. e1
e3e5
e6
e
7
e2
e4
e4
e6e1 e2 e3 e7e5
v1
v3
v4
v2
v5
(e1 e2 e4 e7 )
(e3 e4 e7 )
(e5 e6 e7)
1 1 0 1 0 0
1
0 0 1 1 0 0
1
0 0 0 0 1 1
1
circuit matrix
Rank of a matrix is defined as the order of largest square sub-
matrix whose determinate is not zero.
58. circuit matrix
Rearrange rows and columns of Bf:-
●Arrange the columns in Bf such that all the (e -n + 1) chords correspond to
the first
(e - n + 1) columns.
●Furthermore, Rearrange the rows such that the first row corresponds to
the fundamental circuit made by the chord in the first column, the second
row to the fundamental circuit made by the second, and so on.
60. circuit matrix
We can write matrix Bf (arranged) can be written as, Bf = [Iµ Bt ]
● Iµ is an identity matrix of order µ = e - n +1 ,
● Bt is the remaining µ by (n - I) sub-matrix, corresponding to the
branches of the spanning tree.
e1 e5e2 e3 e6 e7e4
(e3 e4 e7 )
(e5 e6 e7 ) 0 0 1 0 0 1
1
0 1 0 0 1 0
1
1 0 0 1 1 0
1
(e1 e2 e4 e7 )
Bf =[ Iµ Bt ]
Here Iµ is the largest square(3 x 3) sub-matrix .
Iµ is an identity matrix whose determinate is always 1 t.e. non-zero
Rank of Bf is 3
● the rank of Bf= µ = e - n + I.
● Since Bf is a sub-matrix of the circuit matrix
B, then , rank of Circuit matrix(B) ≥ e - n + I.
61. Calculate the cut set of friends . Place them in your
heart and others ; leave in past |( Chapter 4 begins …
)
62. Let G be a graph with m edges and q cut-sets. The cut-set matrix C =
[ci j]q×m of G is a (0,1)-matrix with
1 , if ith cut set contains jth edge
0 , else
Ci,j=
67. In non separable graph
Since every set of edges incident on a vertex is a cut-set
Therefore every row of incidence matrix A(G) is included as a row in
the cut-set matrix C(G).
So C(G) contains A(G)
68. For non separable graph
The incidence matrix of each block is contained in the cut-set
matrix.
Ex. In the graph the incidence matrix of the block {e3,e4,e5,e6,e7} is
4X5 submatrix of C, left after deleting row c1,c2,c5,c8 and columns
e1,e2,e8.
a b c d
f e c7
c5
e1
e2
c6
c1
e8
c8
e6
e5
e7 e3
e4
c4 c3
c2
C(G1)=
c1
c2
c3
c4
c5
c6
c7
c8
e1 e2 e3 e4 e5 e6 e7 e8
0 0 0 0 0 0 0 1
1 1 0 0 0 0 0 0
0 0 1 0 1 0 0 0
0 0 0 0 1 1 1 0
0 0 1 0 0 1 1 0
0 0 0 1 0 1 0
00 0 1 1 0 0 1 0
0 0 0 1 1 0 1 0
69. Since the number of edges common to a cut set and circuit is always
even ,each row in C is orthogonal to every row is B, provided the
edge in both B and C are arranged in same order. In other words
B.CT=C.BT=0 (mod 2)
70. From the last observation we can conclude that -
The rank C(G)>= rank A(G)
Therefore for connected graph of n vertices
Rank C(G) >= n−1. ------------------(1)
71. So, applying Sylvester’s theorem to equation (1) we get
rank B+ rank C <=e
Now for a connected graph
Rank B=e-n+1 .
Rank C <= n−1. ----------------------------(2)
Combining equation (1) and (2)
We get rank C=n-1
Sylvester Theorem
If A and B are matrices of order k×m and n×p respectively,
then nullity AB ≤ nullity A+ nullity B
72. The rank of the cut set matrix is equal to the rank of the incidence
matrix A(G), which equals the rank of graph G.
Soln..As if circuit matrix, the cut set matrix generally has many
redundant(or linearly dependent) rows, therefore we can define Cf
(fundamental cut set matrix).
So Cf is n-1 by e sub matrix of C such that each row correspondent to
the set of fundamental cut set of some spanning tree.
so Cf = [Cc|In-1 ]
73. Bf=[Iμ| Bf]
Cf=[Cc|In-1]
Where t denotes the sub matrix corresponding to the branches of a
spanning tree.
And subscript c denote the sub matrix corresponding to the chords.
b c d a e f g h
1 0 0 1 0 0 0 0
0 1 0 0 1 0 0 0
0 0 1 0 0 1 0 0
0 1 1 0 0 0 1 0
0 0 0 0 0 0 0 1
Cf=
h e
a
b
f g
d
c
74. Similarly we can partition the fundamental incidence matrix Af into two
sub matrices.
Af=[Ac|At] where At consist of n-1 columns of branches and Ac with rest of
the sub matrix i.e. e-n+1 number of chords.
Since the columns in Af and Bf are arranged in the same order, the
equation
ABT =BAT = 0(mod 2) gives Af BT
f equivalent to 0(mod 2),
Iµ
OR AC ⁞ At … is equivalent to 0(mod 2)
BT
f
Ac +AtBT
f is equivalent to 0(mod 2).
75. Since At is non singular, A−1
t exists. Now, multiplying both sides of
equation by A−1
t , we get
A−1
t Ac +A−1
t AtBT
t is equivalent to 0(mod 2),
or A−1
t Ac +BT
t is equivalent to 0(mod 2).
Therefore, A−1
t Ac = −BT
t .
Since in mod 2 arithmetic −1 = 1,
BT
t = A−1
t Ac.
Af
0 0 1 0 0 1 0 0
0 0 0 0 1 1 1 1
0 0 0 0 0 0 0 1
1 1 0 1 1 0 0 0
0 1 1 0 0 0 1 0
Ac
At
1 0 0 0 0
0 1 0 1 0
0 0 1 1 0Bt
1 0 0
0 1 0
0 0 1
0 1 1
0 0 0
At
-1Ac= Hence At
-1Ac=Bt
T
76. Now as the columns in Bf and Cf are arranged in the same order,
therefore
(in mod 2 arithmetic) Cf . Bt
f is equivalent to 0(mod 2) in mod 2
arithmetic gives
Cf .BT
f= 0. (as −1 = 1 in mod 2 arithmetic).
Hence, Cc = A−1
t Ac
77. We make the following observations from the above relations.
1. If A or Af is given, we can construct Bf and Cf starting from an arbitrary
spanning tree and its sub matrix At in Af .
2. If either Bf or Cf is given, we can construct the other. Therefore, since
Bf determines a graph within 2-isomorphism, so does Cf .
3. If either Bf and Cf is given, then Af in general cannot be determined
completely.
78. Everything comes to earth with a lifespan . Choice is your’s ,
live it or waste it . If you waste , Please don’t blame God in
the END Game .
79. We are describe the following topic :
1. Need of a graph
2. Need of computer processing
3. Presentation of a graph with various properties
4. Observe their characteristics
80. Our topic is collected from the book
“ GRAPH THEORY – BY NARSINGH DEO ”
“Matrix representation of Graph” – chapter 7 .
81. Beside of that book majority of our idea and concept comes
through Internet , links are as follows :
math.com
youtube.com
wikipedia.org
cs.cmu.edu
nptel.ac.in
quora.com
cs.xu.edu
82. "We can always find something to be thankful for, and there may be
reasons why we ought to be thankful for even those dispensations
which appear dark and frowning." - Albert Barnes