Cannot get labels to color in GNUPlot

Question

I have been working with some variety of this file for a while:

$DATA << EOD
0.910731391716549   0.0917930320554009  LABEL1  '#008000'
0.871162274545609   0.181191762678911   LABEL2  '#ffff00'
EOD
set key off
set border 3; set tics nomirror
set xrange [0:*]
plot "$DATA" using 1:2:3:4 with labels textcolor rgb variable

this is based on gnuplot scatter plot, labels with color

which should make a scatterplot, with labels LABEL1 and LABEL2 but when I run GNUPlot gnuplot 5.2 patchlevel 8 I get this error:

"/tmp/oBjdIStjpA" line 13: warning: Skipping data file with no valid points

plot "$DATA" using 1:2:3:4 with labels textcolor rgb variable
                                                             ^
"/tmp/oBjdIStjpA" line 13: x range is invalid

This error makes no sense.

If I change the plot line to plot "$DATA" using 1:2:3:4 with labels GNUPlot works, but without the colors that I want.

I'm not using the same color coding that the other poster did, and I don't know how to convert to whatever decimal coding that the other poster used.

How can I get colors for each point?

Answer 1

Check help colorspec. There it says textcolor rgb variable takes numerical values (not text).

So, if you change '#008000' and '#ffff00' to 0x008000 and 0xffff00 it should work.

Addition:

If you don't want to change your original data you simply define a function which converts the string into an integer number.

Code:

### string color variable to integer
reset session

$Data <<EOD
1   1   Label1   '#ff0000'
2   2   Label2   '#00ff00'
3   3   Label3   '#0000ff'
4   4   Label4   '#ff00ff'
5   5   Label5   '#ffff00'
6   6   Label6   '#00ffff'
EOD

unset key
set xrange [0:7]
set yrange [0:7]
myColor(col) = int('0x'.strcol(col)[3:])

plot $Data using 1:2:3:(myColor(4)) w labels tc rgb var font ",17"
### end of code

Result: