带表面图和点的Gnuplot

Question

I tried to do it like suggested in other posts. But the points were not printed. Where is my mistake:

set decimalsign locale
set datafile separator ";"

set table 'point_data.dat'
    unset dgrid3d
    splot './points.csv' u 1:2:3
unset table

#set pm3d implicit at s
#set pm3d interpolate 1,1 flush begin noftriangles hidden3d 100 corners2color mean
set dgrid3d 50,50,50

set output 'field.pdf'

splot './point_data.dat' u 1:2:3 w points pt 7, \
      './field.csv' u 2:1:3 with lines lt 5 lc rgb "#000000"

set output
exit

Thanks for Help

Answer 1

I assume your issue is the datafile separator .
If you look at the point_data.dat file, I'm sure it will list your points in columns but not separated by ; . Thus, when you attempt to plot both the point_data.dat and the field.csv (which I assume is separated by ; as well), the points will most likely not be plotted because gnuplot cannot interpret the point_data.dat -file (which uses the default separator of " " ).
There are two ways to overcome this:

1. Do not use set datafile separator . Instead, use awk to remove the ; while plotting:

    set decimalsign locale set table 'point_data.dat' unset dgrid3d splot "< awk 'BEGIN {FS=\\";\\"} {print $1, $2, $3}' points.csv" u 1:2:3 unset table set dgrid3d 50,50,50 splot "point_data.dat" u 1:2:3 w points pt 7, \\ "< awk 'BEGIN {FS=\\";\\"} {print $1, $2, $3}' field.csv" u 2:1:3 with lines lt 5 lc rgb "#000000" 

   A few things to notice:

   • inside the awk -command, do not forgot to use backslashes with the quotation marks: \\" or else it will mess up the command (and result in an error).
   • consider unsing not to suppress a legend entry or use a defined title (eg title "points" ), otherwise the whole awk -command will be printed as title.

2. You can use the multiplot -command (and skip the set table ):

    set datafile separator ";" set xrange [xmin:xmax] set yrange [ymin:ymax] set zrange [zmin:zmax] set multiplot splot "points.csv" u 1:2:3 w points pt 7 not set dgrid3d 50,50,50 splot "field.csv" u 2:1:3 with lines lt 5 lc rgb "#000000" not unset dgrid3d unset multiplot 

   A few things to notice:

   • use not to print without legend, or else they will overlap. If you need a legend, you cannot use multiplot like this, because they will overlap.
   • set the xrange , yrange and zrange before you plot, or else the axis ranges might not agree. (Be sure to replace xmin etc with the actual values from your data range).