Creating 2D Line Plot using GNU Plot Software

A simple Gnuplot script designed to generate a customized 2D line plot of potential energy data (presumably vs. simulation steps or time), using data from a file named PE.txt (available in GitHub). The script applies several visual formatting settings to make the plot visually appealing and informative.

This script produces a clean, stylized 2D plot of potential energy vs. simulation steps with (1) custom fonts, colors, and line styles, (2) no legend, (3) margins around the x-axis, and (4) automatic y-axis scaling.

Source Code

set title '{/Times-New-Roman=14:Bold Potential Energy Plot}' tc rgb '#167116'
set xlabel '{/Arial:Italic Number of steps}' tc rgb 'red'
set ylabel '{/Arial:Italic Potential energy}' tc rgb 'red'
set style line 1 lt 1 lc rgb '#f70453' lw 0.5
set grid layerdefault lt 0 lc rgb 'blue' lw 0.5
set border lt 1 lc rgb 'blue' lw 1
unset key
plot 'PE.txt' with lines ls 1
set xrange [GPVAL_DATA_X_MIN-0.5:GPVAL_DATA_X_MAX+0.5]
set yrange [*:*]
replot

Line-by-line explanation of the script is below:

1. Plot Title

set title '{/Times-New-Roman=14:Bold Potential Energy Plot}' tc rgb '#167116'

• Title Text: "Potential Energy Plot"
• Font: Times New Roman, size 14, bold
• Text Color: RGB color #167116 (a shade of green)
• tc = text color

2. X and Y Axis Labels

set xlabel '{/Arial:Italic Number of steps}' tc rgb 'red'
set ylabel '{/Arial:Italic Potential energy}' tc rgb 'red'

• X-axis Label: "Number of steps", italic, Arial font, red
• Y-axis Label: "Potential energy", same formatting

3. Line Style Configuration

set style line 1 lt 1 lc rgb '#f70453' lw 0.5

• Defines line style 1:
  • lt 1: Line type 1 (solid)
  • lc rgb '#f70453': Custom RGB color (hot pink/red)
  • lw 0.5: Line width 0.5 (thin line)

4. Grid Lines

set grid layerdefault lt 0 lc rgb 'blue' lw 0.5

• Adds a blue grid to the plot:
• lt 0: Line type 0 (dotted or dashed, depending on terminal)
• lw 0.5: Thin line

5. Border Styling

set border lt 1 lc rgb 'blue' lw 1

• Sets the border color to blue
• Line type 1 and width 1 for visibility

6. Hide Legend (Key)

unset key

• Removes the legend from the plot (useful if only plotting one dataset)

7. Plot Command

plot PE.txt with lines ls 1

• Plots the data from file PE.txt
• Uses line style 1, as defined earlier (thin hot pink/red line)

8. Set X Range with Margins

set xrange [GPVAL_DATA_X_MIN-0.5:GPVAL_DATA_X_MAX+0.5]

• Dynamically adjusts the X-axis limits:
  • GPVAL_DATA_X_MIN and GPVAL_DATA_X_MAX are automatic Gnuplot variables holding the min/max X values from the last plot.
  • Adds a margin of 0.5 units on both sides

9. Set Y Range (Auto)

set yrange [*:*]

• Automatically scales the Y-axis based on the data (no manual limits)

10. Replot

replot

• Re-draws the plot with the updated axis ranges