Sample result of error bar lengths in gnuplot.

errorBarLength_gnuplot.md

Error bar length sample in a log scale

Sample result of error bar lengths in gnuplot.

error bar length = y*0.5

errorBars_logScale.gp

#Requirement
#
#G N U P L O T
#	Version 5.2 patchlevel 8    last modified 2019-12-01 
#
#	Copyright (C) 1986-1993, 1998, 2004, 2007-2019
#	Thomas Williams, Colin Kelley and many others
#============
#
#errorBars_logScale.gp
#
set grid;
#
set xrange [:110.0];
set yrange [:1.0e+10];
#
set logscale y 10;
set format y '10^{%L}';
#
set xlabel '{/Times:Italic=30 x}';
set ylabel '{/Times:Italic=30 y}';
#
set tics font 'Times,20';
set key font 'Times,20';
#
set key title '{/Times Error bar length = {/:Italic y}*0.5}';
set key right;
#---
#
#---
set tmargin at screen 0.95;
set lmargin at screen 0.25;
set rmargin at screen 0.95;
set bmargin at screen 0.20;
set ylabel offset -3.5,0.0;
#---
#
array X[10]=[10.0,20.0,30.0,40.0,50.0,60.0,70.0,80.0,90.0,100.0];
array Y[10]=[1.0e+0,1.0e+1,1.0e+2,1.0e+3,1.0e+4,1.0e+5,1.0e+6,1.0e+7,1.0e+8,1.0e+9];
#============
#
plot Y using (X[$1]):(Y[$1]) with lines notitle linecolor rgb '#0000ff',Y using (X[$1]):(Y[$1]):(Y[$1]*0.5) with yerrorbars notitle pointtype -1 linecolor rgb '#000000';
#
#============
#
#output: svg
#------------
set terminal svg size 600,600 background '#ffffff';
set output './errorBars_logScale.svg';
replot;
#------------
#
#output: png
#------------
set terminal png size 600,600;
set output './errorBars_logScale.png';
#
set xtics offset 0.0,-0.3;
#
replot;
#------------
#
#to reset terminal
set output;
#

errorBars_logScale.svg