如何在 gnuplot 中绘制条形图？

plot "data.dat" using 2: xtic(1) with histogram

Here data.dat contains data of the form

title 1
title2 3
"long title" 5

I recommend Derek Bruening's bar graph generator Perl script. Available at http://www.burningcutlery.com/derek/bargraph/

Simple bar graph:

set boxwidth 0.5
set style fill solid
plot "data.dat" using 1:3:xtic(2) with boxes

data.dat:

0 label       100
1 label2      450
2 "bar label" 75

If you want to style your bars differently, you can do something like:

set style line 1 lc rgb "red"
set style line 2 lc rgb "blue"


set style fill solid
set boxwidth 0.5


plot "data.dat" every ::0::0 using 1:3:xtic(2) with boxes ls 1, \
"data.dat" every ::1::2 using 1:3:xtic(2) with boxes ls 2

If you want to do multiple bars for each entry:

data.dat:

0     5
0.5   6




1.5   3
2     7




3     8
3.5   1

gnuplot:

set xtics ("label" 0.25, "label2" 1.75, "bar label" 3.25,)


set boxwidth 0.5
set style fill solid


plot 'data.dat' every 2    using 1:2 with boxes ls 1,\
'data.dat' every 2::1 using 1:2 with boxes ls 2

If you want to be tricky and use some neat gnuplot tricks:

Gnuplot has psuedo-columns that can be used as the index to color:

plot 'data.dat' using 1:2:0 with boxes lc variable

Further you can use a function to pick the colors you want:

mycolor(x) = ((x*11244898) + 2851770)
plot 'data.dat' using 1:2:(mycolor($0)) with boxes lc rgb variable

Note: you will have to add a couple other basic commands to get the same effect as the sample images.

I would just like to expand upon the top answer, which uses GNUPlot to create a bar graph, for absolute beginners because I read the answer and was still confused from the deluge of syntax.

We begin by writing a text file of GNUplot commands. Lets call it commands.txt:

set term png
set output "graph.png"
set boxwidth 0.5
set style fill solid
plot "data.dat" using 1:3:xtic(2) with boxes

set term png will set GNUplot to output a .png file and set output "graph.png" is the name of the file it will output to.

The next two lines are rather self explanatory. The fifth line contains a lot of syntax.

plot "data.dat" using 1:3:xtic(2) with boxes

"data.dat" is the data file we are operating on. 1:3 indicates we will be using column 1 of data.dat for the x-coordinates and column 3 of data.dat for the y-coordinates. xtic() is a function that is responsible for numbering/labeling the x-axis. xtic(2), therefore, indicates that we will be using column 2 of data.dat for labels.

"data.dat" looks like this:

0 label       100
1 label2      450
2 "bar label" 75

To plot the graph, enter gnuplot commands.txt in terminal.

You can directly use the style histograms provide by gnuplot. This is an example if you have two file in output:

set style data histograms
set style fill solid
set boxwidth 0.5
plot "file1.dat" using 5 title "Total1" lt rgb "#406090",\
"file2.dat" using 5 title "Total2" lt rgb "#40FF00"