gnuplot: Not enough columns for variable color

Question

I am executing the following gnuplot script:

set title "Efficiency scatter plot"
set xlabel "perf_1"
set ylabel "secondary report"
set log x
set log y
set xrange [0.1:40.0]
set yrange [0.1:40.0]
set terminal png medium
set output "./graph1.png"
set size square
set multiplot
set pointsize 0.3
set style line 6 pt 6
set datafile separator ","
set border 3
set xtics nomirror
set ytics nomirror
plot '/tmp/data.csv' using 3:1 with points pt 1 lt 3  lc var title     "perf_20140113131309", \
 '/tmp/data.csv' using 3:2 with points pt 1 lt 1  lc var title "perf_1"
plot x notitle
plot 2*x notitle
plot 0.5*x notitle

obtaining the following error message

 "script.gnuplot", line 20: Not enough columns for variable color

Could you please guide me in order to find what I am doing wrong.

By the way the gnuplot version is '4.6 patchlevel 3' the data.csv files used is

 0.1,0.1,40.0
 0.14,0.14,40.0
 0.32,0.32,40.0
 0.7,0.74,40.0

Thanks in advance!

Answer 1

That means, that you need to specify one more column in your using statement: The first one is the x-coordinate, the second one the y-coordinate. The one for the variable line color is missing.

Use e.g.

plot '/tmp/data.csv' using 3:1:0 with points pt 1 lt 3 lc var

to use the row number (zeroth column) as linetype index. You can also use e.g. linecolor palette so select the color from the currently defined color palette.