Plotting Big-O with gnuplot

Aug 5, 2021

1 minute read

bigo

Use gnuplot command to run a plt file and ouput a png file.

gnuplot bigo.plt

# File: bigo.plt

set title "Big-O Complexity Chart"
set output "bigo.png"      # output file name
set term png               # output as PNG
set grid                   # show a grid
set xlabel "Elements"
set ylabel "Operations"
set format xy ""           # hide axis ranges
set xrange [1:1000000000]
set yrange [0:1000000000]
set logscale xy            # logarithmic scale for x and y
set style line 1 lw 5
plot\
    gamma(x+1) title "O(n!)",\
    (2**x) title "O(x^n)",\
    (x**3) title "O(n^3)",\
    (x**2) title "O(n^2)",\
    x * log(x) title "O(n log(n))",\
    x title "O(n)",\
    log(x) title "O(log(n))",\
    (1) title "O(1)"

Autobuild

I wrote bigo.plt in vscode and found it helpful to open the output png file in a second pane. VSCode will rerender the image when it changes. Use the following command to rebuild the png when you save the plt file.

while inotifywait -e close_write bigo.plt; do gnuplot ./bigo.plt; done

Brian Wigginton

Autobuild