Histogram using gnuplot with multiple y-axes

Question

I could not find a solution to the following issue I am facing. All SO questions on multi-axis talk about line plots, but I am looking for histograms.

The y-range for the bars are different, so one set of bars are not really seen because of the scale. Here is the data:

Metric A B
M1 0.613416301 0.543734744 
M2 0.000195961 0.000100190

Here is the MWE:

reset
set term postscript eps size 5.5,4.5 enhanced color font 'Arial-Bold' 25
set out 'histplot.eps'
set key right 
set style histogram cluster gap 2 
set style data histograms
set style fill pattern 1.00 border
set y2range [0.0001:0.0002]
plot 'histplot.dat' using 2 ti col, '' u 3:xticlabels(1) ti col
quit

This is the sample output (one set of bars over M2 is not seen):

What I prefer is to have a second y-axis (to the right side of the plot) with a range appropriate to the second row of my data file. Is this possible? Any help is greatly appreciated.

Answer 1

Normally you can plot severyl histograms beneath each other using newhistogram. However, it seems like this is buggy when using patterns as fillstyle:

reset
set style histogram cluster gap 1
set style data histograms
set style fill pattern 1.00 border

set yrange [0:*]
set ytics nomirror
set y2range [0:*]
set y2tics

set key right autotitle columnheader
plot 'histplot.dat' u 2 every ::::0, '' u 3:xtic(1) every ::::0,\
     newhistogram lt 1 at 1,\
     'histplot.dat' u 2 every ::1::1 axes x1y2, '' u 3:xtic(1) every ::1::1 axes x1y2

Alternatively you can use multiplot and plot the two histograms directly beneath each other:

reset
set style histogram cluster gap 1
set style data histograms
set style fill pattern 1.00 border

set yrange [0:*]
set ytics nomirror
set multiplot layout 1,2
set rmargin at screen 0.5
set lmargin 9
unset key
plot 'histplot.dat' using 2 every ::::0 ti col, '' u 3:xticlabels(1) every ::::0 ti col

set rmargin 9
set lmargin at screen 0.5
unset ytics
set y2range [0:*]
set y2tics
set key right
plot '' using 2 every ::1::1 axes x1y2 ti col, '' u 3:xtic(1) every ::1::1 axes x1y2 ti col
unset multiplot

If you don't want the separating black line, you can use set border 7 for the first and set border 13 for the second plot.