Back to homepage

It can operate in interactive mode, or read commands and data from files. Here are some basic use examples to get you started. Type in: gnuplot to start the program. You will be presented with intro screen and interactive command prompt (gnuplot>). You can type help or this formula to get you started: gnuplot> plot sin(x) Another graphical window will be created, with sin(x) plotted. You can copy that to clipboard etc. Now try: gnuplot> plot f(x)=x ^ function to plot expected We get error message. For some odd reason, this works: gnuplot> plot f(x)=x,f(x) and makes a nice graph in a separate window.

gnuplot> plot f(x)=(x*x)/(1-x),f(x)

Graph of function f(x)=(x*x)/(1-x).

There can be several functions plotted on the same graph. Here we plot sin(x) functions with three different periods: one, two and four: gnuplot> plot f(x)=sin(x*b),b=1,f(x),b=0.5,f(x),b=0.25,f(x)

Three sin(x) functions with different periods drawn on the same graph.

Harmonic addition of those three individual functions: gnuplot> plot f(x)=sin(x*b)+sin(x*0.5*b)+sin(x*0.25*b),b=1,f(x)

Harmonic addition of three functions.

To ensure that only certain horizontal range is shown, enter range before function: gnuplot> plot [-20:20] sin(x)+cos(x)+tan(x)

Only given horizontal range (-20:20) of function is plotted.

To set particular number increments for x and y axis: gnuplot> set xtics pi gnuplot> set ytics 5 Then: gnuplot> plot [-2*pi:2*pi] (sin(x)+cos(x))*tan(x)

How to specify particular increments for x and y axis.

Now for 3D (three-dimensional) plot with set x and y ranges and tics: gnuplot> set xtics 0.5 gnuplot> set ytics 0.5 gnuplot> splot [x=-5:5] [y=-5:5] sin(x) * cos(y)

Basic 3D plot.

Filled up color plot: gnuplot> set xlabel "X" gnuplot> set ylabel "Y" gnuplot> set zlabel "Z" gnuplot> set xtics 0.5 gnuplot> set ytics 0.5 gnuplot> set ztics 0.5 gnuplot> set pm3d gnuplot> set hidden3d gnuplot> splot [x=-3:3] [y=-3:3] sin(x) * (0.3*tan(y))

This gives 3D colour plot.

Plotting data from files using Gnuplot: gnuplot> plot "testdata1.tsv" using 1:2

This will only work if you have already prepared a human readable text file with values.

Here is one to get you started.

It is using tab delimeters for data, and line with # at the beginning is ignored.

Back to homepage