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NS2: AWK and GNUplot - PArt III

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AWK and GNUplot as used in NS2

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NS2: AWK and GNUplot - PArt III

  1. 1. An Introduction to Network Simulator AWK, GnuPlot Dr. Ajit K Nayak Dept of CSIT, ITER S‘O’A University, BBSR
  2. 2. Part III • Introducing AWK • Introducing gnuPlot
  3. 3. Basics of AWK • AWK is a scripting language suitable for text processing / data extraction and report formatting. • It is interpreted line by line and produces the output in a required format. • Input text files are considered to be a set of records containing different fields, i.e. each line in the file is a record (row) and each word of a line is considered as a field (column). • The default column separator is white space, however other delimiters such as a comma (,), or a tab space may also be used. • First column of the file is accesses using $1, second column using $2 etc. NS-2/AN/Intro/ 3
  4. 4. Example-1 • Let us consider a text file (file.txt) with the following content. Ashok 20-sep-1991 India Marry 13-oct-1995 Italy John 15-mar-1990 USA Karim 25-Feb-1993 Pakistan • Command Line Execution: – Issue the following commands in the command prompt. awk < file.txt ’{print $2}’ or awk ’{print $2}’ file.txt • It will display the second field(column) of each line available in a text file called ’file.txt’. NS-2/AN/Intro/ 4
  5. 5. General Structure of AWK BEGIN action(s) A set of patterns action(s) pair END action(s) • All actions with BEGIN pattern are executed once at the beginning of the execution of the script. Normally the variable initializations are made in this section. • The pattern-action pair between BEGIN and END pattern are executed for each line of the input file. • Finally actions with END pattern are executed once at the end. END section is normally used for printing the summarized results. NS-2/AN/Intro/ 5
  6. 6. Example • Let us consider a text file (file.txt) with the following content. 1001 Ashok 83 73 93 1002 Ram 30 43 67 1003 John 45 69 83 1004 Marry 43 35 59 1005 Samita 20 33 47 1006 Shibani 66 66 76 1007 Sourav 30 25 45 1008 Samyak 71 75 65 1009 Rudra 30 43 67 1010 Laila 85 83 87 NS-2/AN/Intro/ 6
  7. 7. Example-2 • Write AWK script to print All the students having first division with their average % score of marks #program to print student names scoring First division BEGIN { lines=0; print "n Students with First Division"; print "========================="; } { lines++; avg=($3+$4+$5)/3; if (avg >= 60) { NS-2/AN/Intro/ 7 printf $2 "t" avg "%n"; } } END{ print “=====*====="; print lines " lines scanned..."; } Execute with: awk -f myFirstAwk.sh < file.txt
  8. 8. Practice Programs • Write and execute all example programs • Write AWK script for the followings – To print the list of Failed students. – To print the list of Poor students. ( avg mark < class avg) Data format: (reg, name m1, m2, m3) NS-2/AN/Intro/ 8
  9. 9. GNUPlot • GNUPlot is a software used to plot graphs using data or functions. • It is a command driven and suitable for 2D as well as 3D plots. • To start, issue the command gnuplot in the command line, that will a result a prompt like, gnuplot> • This is called the gnuplot command line. A plot now can be created using any of the following two ways. i) use the plot command in command line, or ii) create a script file with extension ’<script_file>.p’ then load the script. NS-2/AN/Intro/ 9
  10. 10. Plotting • Plot using a predefined function: gnuplot > plot sin(x)/x • Plot using a data file (scheduling.dat) # Processor requirement for different algorithms #Tasks Alg1 Alg2 Alg3 70 5 8 10 80 6 10 11 90 7 12 12 100 10 14 15 plot “scheduling.dat" using 1:2 title ’Alg1’ with lines, “scheduling.dat" u 1:4 t ’Alg’ w linespoints NS-2/AN/Intro/ 10 #Task Alg1 Alg2 Alg3 110 10 16 18 120 11 19 22 130 12 25 23 140 13 30 24 150 13 34 26
  11. 11. Customizing plots #Gnuplot script file: scheduling.p set autoscale # scale axis automatically set xtic auto # set xtics automatically set ytic auto # set ytics automatically set title "Processor requirement in different Algs" set xlabel "Processors" set ylabel "Tasks" set key 0.01,100 #position of Legend plot "scheduling.dat" u 1:2 t ’Alg1’ w lines , "scheduling.dat" u 1:3 t ’Alg2’ with linespoints • To execute this script: gnuplot> load ’schedule.p’ NS-2/AN/Intro/ 11
  12. 12. Histograms # File name: histo.p; set grid; set style data histograms; set style histogram cluster; set style fill pattern; set key left; plot ’scheduling.dat’ using 2:xtic(1) t “Alg1", "" u 3 t "Alg2", "" u 4 t "Alg3"; • The col1 data of the data file(scheduling.dat) is taken to be the values in the x-axis. • The values in col_2 - col_4 forms three bars in a cluster. • Each row of data file is treated as one cluster and numbers of bars in a cluster is the number of columns considered in the plot command. NS-2/AN/Intro/ 12
  13. 13. Practice Programs • Write and execute all example programs • Consider the data file containing marks of the students in 3 subjects and plot the following graphs. – Draw a line plot containing 3 lines i) regNo vs mark1, ii) regNo vs mark2, and iii) regNo vs mark3. – A histogram that contains regNo in x axis and 3 different marks of one student is plotted as 3 clustered bars for each students. NS-2/AN/Intro/ 13
  14. 14. Output? (twoNode.tr) + 1 0 1 cbr 500 ------- 0 0.0 1.0 0 0 - 1 0 1 cbr 500 ------- 0 0.0 1.0 0 0 + 1.005 0 1 cbr 500 ------- 0 0.0 1.0 1 1 - 1.005 0 1 cbr 500 ------- 0 0.0 1.0 1 1 + 1.01 0 1 cbr 500 ------- 0 0.0 1.0 2 2 - 1.01 0 1 cbr 500 ------- 0 0.0 1.0 2 2 r 1.014 0 1 cbr 500 ------- 0 0.0 1.0 0 0 + 1.015 0 1 cbr 500 ------- 0 0.0 1.0 3 3 - 1.015 0 1 cbr 500 ------- 0 0.0 1.0 3 3 r 1.019 0 1 cbr 500 ------- 0 0.0 1.0 1 1 + 1.02 0 1 cbr 500 ------- 0 0.0 1.0 4 4 - 1.02 0 1 cbr 500 ------- 0 0.0 1.0 4 4 r 1.024 0 1 cbr 500 ------- 0 0.0 1.0 2 2
  15. 15. Explaining Output (I) • Column 1: events – +: enqueue – -: dequeue – r: receive – d: drop • Column 2: – Time of event • Column 3 & 4: – Trace between which two nodes?
  16. 16. Network Performance - I Average Delay: • It is the average of total delay incurred due to all packets. – For each packet i received, find the delay as delayi = arrivalTimePacketi - sendingTimePacketi – Compute Average delay for n packets as follows avgDelay = 1..n delayi / n NS-2/AN/Intro/ 16
  17. 17. Network Performance - II Network Throughput: • It is defined as the total number of bytes received at the destination per sec. – Add the bytes of all data packets received. – Divide the total size calculated in above step by the simulation time. – To get the values in Mbps multiply final value with 8/1000000. NS-2/AN/Intro/ 17
  18. 18. AWK Script to find Packet Statistics #== =packetStat.awk === # Run with: awk -f packetStat.awk < trace.tr BEGIN { totPktRecvd=0 drop=0 } { event = $1 intDest = $4 if (event == "r" && intDest == dest) { totPktRecvd ++ } NS-2/AN/Intro/ 18
  19. 19. AWK Script contd. if (event == "d") { drop++ } } END { printf("Total Packets Recvd = %g n",totPktRecvd) printf("Total Packets Dropped = %g n",drop) } NS-2/AN/Intro/ 19
  20. 20. AWK Script to compute Avg Delay #== =avgDelay.awk === # Run with: awk -f avgDelay.awk < trace.tr BEGIN { for (i in pktSent) { pktSent[i] = 0 } for (i in pktRecvd) { pktRecvd[i] = 0 } delay = avgDelay = 0 } # begin ends here NS-2/AN/Intro/ 20
  21. 21. Avg Delay script contd. { event = $1 time = $2 intSrc=$3 intDest=$4 src=$9 dest=$10 pktSeq = $12 intSrc = (intSrc".0") intDest = (intDest".0") # Store packets send times if (pktSent[pktSeq] == 0 && event == "+" && intSrc == src) { pktSent[pktSeq] = time } NS-2/AN/Intro/ 21
  22. 22. Avg Delay script contd. - I # Store packets arrival time if (event == "r" && intDest == dest) { pktRecvd[pktSeq] = time } } END { # Compute average delay for (i in pktRecvd) { if (pktSent[i] == 0) { printf("nError %gn",i) } delay += pktRecvd[i] - pktSent[i] num ++ } NS-2/AN/Intro/ 22
  23. 23. Avg Delay script contd. - II if (num != 0) { avgDelay = delay / num } else { avgDelay = 0 } printf("Avg Delay = %g msn",avgDelay*1000) } # program ends here NS-2/AN/Intro/ 23
  24. 24. Practice Programs • Write a NS script to implement above program and generate a trace file (trace.tr) • Write one AWK script to find packet statistics and average delay. • Write one AWK script to find average network throughput NS-2/AN/Intro/ 24
  25. 25. Suggested Readings • The GNU Awk User's Guide –http://www.gnu.org/software/gawk/ manual/gawk.html • Official gnuplot documentation –http://www.gnuplot.info/documentation.html NS-2/AN/Intro/ 25
  26. 26. Thank You End of NS2

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