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I am trying generate a pie chart using GNUPLOT, I have already generate the plot, and I have assigned colour to the legend using an array. This is the code, I have used this question as reference

script.sh

#!/usr/bin/gnuplot
set terminal pngcairo nocrop enhanced size 800,400 font "Siemens Sans,8"
set output 'output.png'
filename = 'source.dat'
rowi = 1
rowf = 2

# obtain sum(column(2)) from rows `rowi` to `rowf`
set datafile separator ','
stats filename u 2 every ::rowi::rowf noout prefix "A"

# rowf should not be greater than length of file
rowf = (rowf-rowi > A_records - 1 ? A_records + rowi - 1 : rowf)

angle(x)=x*360/A_sum
percentage(x)=x*100/A_sum

# circumference dimensions for pie-chart
centerX=0
centerY=0
radius=0.2

# label positions
yposmin = 0.0
yposmax = 0.95*radius
xpos = 1.5*radius
ypos(i) = yposmax - i*(yposmax-yposmin)/(1.0*rowf-rowi)

#-------------------------------------------------------------------
# now we can configure the canvas
set style fill solid 1     # filled pie-chart
unset key                  # no automatic labels
unset tics                 # remove tics
unset border               # remove borders; if some label is missing, comment to see what is happening

set size ratio -1              # equal scale length
set xrange [-radius:2*radius]  # [-1:2] leaves space for labels
set yrange [-radius:radius]    # [-1:1]

#-------------------------------------------------------------------
pos = 0             # init angle
colour = 0          # init colour
colors = "blue red"

# 1st line: plot pie-chart
# 2nd line: draw colored boxes at (xpos):(ypos)
# 3rd line: place labels at (xpos+offset):(ypos)
plot filename u (centerX):(centerY):(radius):(pos):(pos=pos+angle($2)):(colour=colour+1) every ::rowi::rowf w circle lc var,\
     for [i=0:rowf-rowi] '+' u (xpos):(ypos(i)) w p pt 5 ps 4 lc rgb word(colors,i+1),\
     for [i=0:rowf-rowi] filename u (xpos):(ypos(i)):(sprintf('%05.2f%% %s', percentage($2), stringcolumn(1))) every ::i+rowi::i+rowi w labels left offset 3,0

The source file to generate the pie chart is this

source.dat

"Tipo","Valor" 
"Periodo laboral",723 
"Periodo no laboral",81 

And when I run the script I get a output.png file that looks like this

output.png

enter image description here

As you can see, the pie chart colours don't fit the legend colour. This is because I can easily set the legend colour thanks to the for index, but for generating the pie chart I am iterating through the every clause so I can't get an index. I have also tried something like:

plot filename u (centerX):(centerY):(radius):(pos):(pos=pos+angle($2)):(colour=colour+1) every ::rowi::rowf w circle lc rgb(word(colors, colour)),\

but I have the following error:

"gnuplot/piechart.sh", line 49: warning: This plot style does not work with 6 cols. Setting to xyerrorbars

Could you help me please? Thanks in advance.

UPDATED

I think I have taken a step. I have removed the (colour=colour+1) part of the plot command, and now I can set an specific color that way

plot filename u (centerX):(centerY):(radius):(pos):(pos=pos+angle($2)):(colour=colour+1) every ::rowi::rowf w circle lc rgb word(colors,colour+1),\

But this draw the pie chart completly blue, and I still need a index or something because it seems colours don't change its value.

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Luis González
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1 Answers1

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Piecewise plotting the pie chart should work:

colorsrgb = "#0000FF #FF0000"

plot for [i=1:rowf-rowi+1] filename u (centerX):(centerY):(radius):(pos):(pos=pos+angle($2)) every ::i::i w circle lc rgb word(colorsrgb, i)

enter image description here

Tested with Gnuplot 5.0.0 on Windows.

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maij
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