Removing blank gap in gnuplot multiplot

gnuplot

Solution

Getting the margins right with `multiplot` is a bit tedious, especially when using `set pm3d map`, which has quite large margins.

Since version 5.0

Since 5.0 version,`multiplot` has the options `margins` and `spacing`.

`margins` takes four numbers `set multiplot margins <left>,<right>,<bottom>,<top>`, which give the fixed overall margins around the multiplot layout. `spacing` takes two number `set multiplot spacing <xspacing>,<yspacing>` which give the distance between two rows (`<yspacing>`) or two columns (`<xspacing>`).

set terminal pngcairo size 800,600 background rgb '#bbbbbb'
set output 'foobar.png'

set multiplot layout 2,2 \
              margins 0.1,0.98,0.1,0.98 \
              spacing 0.08,0.08

set ylabel 'ylabel'
plot x

unset ylabel
plot 2*x

set ylabel 'ylabel'
set xlabel 'xlabel'
plot 3*x

unset ylabel
plot 4*x
unset multiplot

Result (with 5.0rc1):

Earlier versions, kept only for completeness

To achieve the same thing with gnuplot 4.x, you must do the calculations by hand or define some functions, like the following example shows. This should be quite universally usable.

You can put all the general stuff in a configuration file, like `multiplot.gp`, which contains the functions

init_margins(left, right, bottom, top, dx, dy, rows, cols) = \
  sprintf('left_margin = %f; right_margin = %f; top_margin = %f; bottom_margin = %f; ', left, right, top, bottom) . \
  sprintf('col_count = %d; row_count = %d; gap_size_x = %f; gap_size_y = %f', cols, rows, dx, dy)

get_lmargin(col) = (left_margin + (col - 1) * (gap_size_x + ((right_margin - left_margin)-(col_count - 1) * gap_size_x)/col_count))
get_rmargin(col) = (left_margin + (col - 1) * gap_size_x + col * ((right_margin - left_margin)-(col_count - 1) * gap_size_x)/col_count)
get_tmargin(row) = (top_margin  - (row - 1) * gap_size_y - (row-1) * ((top_margin - bottom_margin  - gap_size_y * row_count) / row_count))
get_bmargin(row) = (top_margin  - (row - 1) * gap_size_y -  row    * ((top_margin - bottom_margin  - gap_size_y * row_count) / row_count))
set_margins(col, row) = \
  sprintf('set lmargin at screen %f;', get_lmargin(col)) . \
  sprintf('set rmargin at screen %f;', get_rmargin(col)) . \
  sprintf('set tmargin at screen %f;', get_tmargin(row)) . \
  sprintf('set bmargin at screen %f;', get_bmargin(row))

The main file is then

set terminal pngcairo size 800,600 background rgb '#bbbbbb'
set output 'foobar2.png'

load 'multiplot.gp'

eval(init_margins(0.1, 0.98, 0.1, 0.98, 0.08, 0.08, 2, 2))    
set multiplot

eval(set_margins(1,1))
set ylabel 'ylabel'
plot x

eval(set_margins(2,1))
unset ylabel
plot 2*x

eval(set_margins(1,2))
set ylabel 'ylabel'
set xlabel 'xlabel'
plot 3*x

eval(set_margins(2,2))
unset ylabel
plot 4*x
unset multiplot

With the result (using 4.6.4):

Problem

I am using multiplot in gnuplot to insert four graphs in the single figure. My code looks like this: ``` set term postscript eps enhanced color set xlabel 'i' set ylabel 'j' set xtics 20 set ytics 20 set xlabel font ",20" set ylabel font ",20" set pm3d map set pm3d corners2color c1 set out "Rulkovpattern.eps" set multiplot layout 2,2 set title "(a)" set size square 0.55,0.55 spl 'patternD0pt02.dat' notitle set title "(b)" set size square 0.55,0.55 spl 'patternD0pt04.dat' notitle set size square 0.55,0.55 set title "(c)" spl 'patternD0pt06.dat' notitle set size square 0.55,0.55 set title "(d)" spl 'patternD0pt08.dat' notitle unset multiplot set out set term wxt ``` This generates the following picture: But in this picture, there is a lot of blank space in the middle. I would like to make that space disappear or at least make it as minimum as possible. How can I do it by modifying my code? Thanks in advance

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