The document discusses methods for making graphs with scatter plots numerically readable by adding grid lines. It presents an example of a Lorenz curve graph with credit card purchase data. Adding grid lines at varying densities, such as every 25% for large spacing, 5% for medium, and 1% for fine spacing, can significantly improve the precision of reading numerical values from the graph. Proper gridding enhances readability without overcrowding the graph.

1. To Make Graphs Such As Scatter
Plots Numerically Readable
Toshiyuki Shimono
DG Lab, Digital Garage Inc., Tokyo
Lorenz curve example:
How much percentage of money is
used by the top generous persons?
(A credit card company data is used.)
The vertical value can be arbitrarily
read at any horizontal location.
“Top 20.0% people’s
purchase occupies 77.0%”
“Top 50.0% people’s
purchase occupies 96.2%”
Following(x) vs. followers(y) on twitter
Making a graph is crucial to understand
the meaning of numbers, and “gridding”
significantly enhances the precision in
number reading.
There is still yet much room
in how to put the grids. But just
adding grid lines densely would
cause the graph difficult to read.
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0.00 0.25 0.50 0.75 1.00
0.00
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1.00
(1) Discrete cross grids
(2) Varying the sizes in 3 levels.
(3) Tuning the coordinates of grids.
Every 25% for large, 5% for middle, 1%
for dot-sized grids.
(GNU R is used to plot.)

2. How much percentage of money is used
by the top paying persons by credit cards?
The vertical value can be arbitrarily
read at any horizontal location.
“Top 20.0% people’s
purchase occupies 77.0%”
“Top 50.0% people’s sales
occupies 96.2%”
To Make Graphs Such As Scatter Plots
Numerically Readable Toshiyuki Shimono, Digital Garage.
Lorenz curve example
This graph is *an example* to show how
precisely you can read the coordinates.
“3-layered gridding in
background” helps you
read the coordinates in
a graph. (The gridding
here plays the scaling
marks of 25%, 5%, 1%. )
This page is for the 30-seconds speech.