GNUPlot Example: Plotting Mathematical Functions in Linux

This guide demonstrates how to use GNUPlot to visualize mathematical functions in a Linux environment.

Installation

Install GNUPlot using your package manager:

# Debian/Ubuntu
sudo apt update
sudo apt install gnuplot

# Fedora/RHEL
sudo dnf install gnuplot

# Arch Linux
sudo pacman -S gnuplot

Basic Plot Example (Sine Wave)

Launch GNUPlot:
```
gnuplot
```

Enter the following commands in the GNUPlot prompt:

set title "Sine Wave Example"
set xlabel "x"
set ylabel "sin(x)"
plot sin(x) with lines title "y = sin(x)"

This will display an interactive plot of the sine function.

Saving the Plot to a File

To save the plot as a PNG image:

set terminal png
set output "sine_wave.png"
plot sin(x) with lines title "y = sin(x)"

The file sine_wave.png will be created in the current directory.

Multiple Functions Example

Plot both sine and cosine functions:

set title "Trigonometric Functions"
set xlabel "x"
set ylabel "y"
set xrange [-2*pi:2*pi]
plot sin(x) with lines title "sin(x)", cos(x) with lines title "cos(x)"

Script-Based Plotting

Create a script file (e.g., plot_script.gp):

set terminal png
set output "math_plot.png"
set title "Quadratic Function"
set xlabel "x"
set ylabel "y"
plot x**2 with lines title "y = x^2"

Execute the script:
```
gnuplot plot_script.gp
```

3D Plot Example

Generate a 3D surface plot:

set terminal png
set output "3d_plot.png"
splot sin(x)*cos(y) with pm3d title "sin(x)*cos(y)"

Viewing the Plot

GUI Environment: GNUPlot will display the plot in a new window.
Terminal/SSH: Save the plot as an image (PNG/PDF) and transfer it for viewing.

Notes

Replace x**2 with any mathematical function (e.g., exp(x), log(x)).
Use set xrange [min:max] and set yrange [min:max] to adjust axes.