Gnuplot error bars values below 1 doesn't appear - gnuplot

Question

I have those data:
Length A B C D E F A_err B_err C_err D_err E_err F_err
17 0,51 1,4 0 0 0 0,07 0,11 0,33 0 0 0 0,08
18 1,33 2,49 1,88 0,51 1,21 0,2 0,18 0,43 1,05 0,5 0,5 0,14
19 2,56 3,83 3,75 0,76 4,22 0,81 0,25 0,53 1,47 0,61 0,92 0,28
20 8,28 7,22 3,44 5,46 5,16 9,19 0,44 0,72 1,41 1,59 1,02 0,89
21 29,96 20 15,78 16,65 13,66 62,58 0,74 1,11 2,82 2,6 1,58 1,49
22 34,16 42,3 56,25 31,51 37,14 16 0,76 1,37 3,84 3,25 2,22 1,13
23 14,23 16,59 17,03 29,86 21,28 1,55 0,56 1,03 2,91 3,2 1,88 0,38
24 6,98 4,39 1,72 12,58 9,6 9,54 0,41 0,57 1,01 2,32 1,35 0,9
25 1,23 1,02 0,16 1,65 4,55 0,05 0,18 0,28 0,31 0,89 0,96 0,07
26 0,45 0,44 0 0,89 1,76 0 0,11 0,18 0 0,66 0,6 0
27 0,18 0,1 0 0 1,04 0 0,07 0,09 0 0 0,47 0
With this code, I obtain a nice histogram with error bars:
set terminal pngcairo enhanced font "arial,15" fontscale 2.0 size 1600,900
set output 'length.png'
set style fill solid 0.7 border lt -1
set key inside right top vertical Right noreverse noenhanced autotitles columnhead nobox
set grid ytics
set nokey
set style histogram errorbars linewidth 1 gap 3 title offset character 0, 0, 0
set datafile missing '-'
set style data histograms
set xtics border in scale 1,0.5 nomirror offset character 0, 0, 0 autojustify
set xtics norangelimit font ",12"
set xtics ()
set xlabel "n"
set ylabel "Percentage (%)"
set title "length"
set bars 0.3 front
set datafile separator "\t"
set yrange [ 0 : * ] noreverse nowriteback
plot 'length.dat' using 2:8:xtic(1), '' u 3:9:xtic(1), '' u 4:10:xtic(1), '' u 5:11:xtic(1), '' u 6:12:xtic(1), '' u 7:13:xtic(1)
The obtained image is here: http://i.stack.imgur.com/s88QJ.png
But, some error bars just not appear. I notice that is because the error value is below 1. But why ? I'd like all error bars appearing. Is there a problem in the code that forbid errors below 1 to appear ?
Thanks for your help

Answer 1

To me, it looks like your problem is that you're using , as a decimal point character in your file instead of . that gnuplot understands natively. There are two possible solutions. The first I found from googling, but can't test:
set locale
or
set locale "ja_JP.UTF-8" #gnuplot complains this isn't available for me ...
or perhaps set decimalsign local "..."
The second solution is a little less elegant, but it involves converting all of your , to . in your datafile. That's a trivial thing to do using sed:
sed -e 's/,/\./g' length.dat > length2.dat
Now you can just plot using length2.dat and it should work OK (it did for me). As an aside, I think that's quite a nicely colorful plot. The pngcairo terminal does a good job with it.