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Editorial Team
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Asked: 2026-06-12T19:57:50+00:00

I would like to produce a spider (aka radar/star) plot using Gnuplot where different

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I would like to produce a spider (aka radar/star) plot using Gnuplot where different axes have independent scales. I am able to produce such a plot using OriginPro (commercial), but with Gnuplot I am only able to set a radar plot with uniform scale.

The (csv file) dataset looks like the following (first row is column labels):

# FEATURE, Product_A, Product_B, Product_C, Product_D
attribute_1, 2, 10, 7, 3.5
attribute_2, 1, 0.5, 3,4
attribute_3, 37, 58, 49, 72
attribute_4, 1985, 1992, 2006, 2010
attribute_5, 0.1, 0.5, 0.3, 0.8

and the plot I am looking for is this one: https://www.dropbox.com/s/uvqubzqvm6puhb8/spider.pdf –
As you can see each axis stands for a different attribute, and has its own scale.

I guess the Gnuplot starting code is:

set polar
set grid polar
set angles degrees
set size square
set style data filledcurves

But I don’t know how to proceed. Any suggestions?

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1 Answer

  1. Editorial Team

    The answer by @george helped me figure out how to rearrange the dataset, in order to pick from it the corresponding attribute data.
    Because I was also looking for different range scales for the different spider axes, in addition to @george’s suggestion, I thought that an axis-specific normalisation to the common [0:1] range, would have the problem solved. The main modification is then related to the using field of the plot command.

    The code is fairly lengthy, I’m sure it could be optimised. It could also be merged into a script or a simple C code, in order to let the user decide the number of axes (number of attributes), and the different ranges (min, max) for each specific axis.

    The following example is for 5 attributes comparing 2 products. Here is shown the plot result image:

    set nokey
set polar
set angles degrees
npoints = 5
a1 = 360/npoints*1
a2= 360/npoints*2
a3= 360/npoints*3
a4= 360/npoints*4
a5= 360/npoints*5
set grid polar 360.
set size square
set style data lines
unset border
set arrow nohead from 0,0 to first 1*cos(a1) , 1*sin(a1)
set arrow nohead from 0,0 to first 1*cos(a2) , 1*sin(a2)
set arrow nohead from 0,0 to first 1*cos(a3) , 1*sin(a3)
set arrow nohead from 0,0 to first 1*cos(a4) , 1*sin(a4)
set arrow nohead from 0,0 to first 1*cos(a5) , 1*sin(a5)
a1_max = 10
a2_max = 5
a3_max = 100
a4_max = 2020
a5_max = 1
a1_min = 0
a2_min = 0
a3_min = 50
a4_min = 1980
a5_min = 0
set label "(0:10)" at cos(a1),sin(a1) center offset char 1,1
set label "(0:5)" at cos(a2),sin(a2) center offset char -1,1
set label "(50:100)" at cos(a3),sin(a3) center offset char -1,-1
set label "(1980:2020)" at cos(a4),sin(a4) center offset char 0,-1
set label "(0:1)" at cos(a5),sin(a5) center offset char 3,0
set xrange [-1:1]
set yrange [-1:1]
unset xtics
unset ytics
set rrange [0:1]
set rtics (""0,""0.25,""0.5,""0.75,""1)

plot '-' using ($1==1?a1:($1==2?a2:($1==3?a3:($1==4?a4:($1==5?a5:$1))))):($1==1?(($2-a1_min)/(a1_max-a1_min)):($1==2?(($2-a2_min)/(a2_max-a2_min)):($1==3?(($2-a3_min)/(a3_max-a3_min)):($1==4?(($2-a4_min)/(a4_max-a4_min)):($1==5?(($2-a5_min)/(a5_max-a5_min)):$1))))) w l
1 8
2 3
3 67
4 2000
5 0.2
1 8

plot '-' using ($1==1?a1:($1==2?a2:($1==3?a3:($1==4?a4:($1==5?a5:$1))))):($1==1?(($2-a1_min)/(a1_max-a1_min)):($1==2?(($2-a2_min)/(a2_max-a2_min)):($1==3?(($2-a3_min)/(a3_max-a3_min)):($1==4?(($2-a4_min)/(a4_max-a4_min)):($1==5?(($2-a5_min)/(a5_max-a5_min)):$1))))) w l
1 6
2 1.5
3 85
4 2010
5 0.5
1 6
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