Gnuplot

Contents 1 References 2 Usage 2.1 Basic Usage 2.2 3D Plot Data File 2.3 2D Plot Data File

References

• Demo Scripts
• Documentation

Usage

Basic Usage

Create PNG with sine plot:

gnuplot> set terminal png small
gnuplot> set out 'somefile.png'
gnuplot> plot sin(x)+sin(2*x)

3D Plot Data File

Plot

set terminal png font "/usr/share/fonts/corefonts/arial.ttf" 12 size 800,600
#set terminal PDF output font-size 12
set out "test.png"
set xlabel "x"
set ylabel "y"
set zlabel "sin(x)+sin(y)"
set key below
set nogrid
set view 45,30,1.0 # view angles (rotation around x, rotation around y, zoom)
set xrange [-3:3]
set yrange [-3:3]
set zrange [-2:2]
splot "datafile.dat" with lines

Generate test data

-3.step(3, 0.1) do |x|
    -3.step(3, 0.1) do |y|
        z = Math.sin(x)+Math.sin(y)
        puts "#{x} #{y} #{z}"
    end
    puts # groups points with same x values
end

The output data looks like this

-3.0 -3.0 -0.282240016119734
-3.0 -2.9 -0.38036933727385
-3.0 -2.8 -0.476108158215772
-3.0 -2.7 -0.568499888293697
-3.0 -2.6 -0.656621379881331

2D Plot Data File

Create data file:

$ vim createdata.py
import math
d = 0
while d < 2 * math.pi:
    print d,',',sin(d)+sin(2*d)
    d += 2 * math.pi / 100
$ python createdata.py > datafile

The program outputs this:

0 , 0.0
0.0628318530718 , 0.00394264934276
0.125663706144 , 0.0157084194357
0.188495559215 , 0.0351117570559
0.251327412287 , 0.0618466599781

Create gnuplot program:

$ vim dataplot.gnuplot
set terminal png small
set out 'somefile.png'
plot 'datafile' using '%lf , %lf'
                       |_ plot the second column as a
                          function of the first