Histogram Cluster / Bar Chart
I'm trying to generate the following histogram cluster out of this data file with gnuplot, where each category is represented in a separate line per year in the data file:
# datafile year category num_of_events 2011 "Category 1" 213 2011 "Category 2" 240 2011 "Category 3" 220 2012 "Category 1" 222 2012 "Category 2" 238 ...
But I don't know how to do it with one line per category. I would be glad if anybody has got an idea how to do this with gnuplot.
Stacked Histogram Cluster / Stacked Bar Chart
Even better would be a stacked histogram cluster like the following, where the stacked sub categories are represented by separate columns in the datafile:
# datafile year category num_of_events_for_A num_of_events_for_B 2011 "Category 1" 213 30 2011 "Category 2" 240 28 2011 "Category 3" 220 25 2012 "Category 1" 222 13 2012 "Category 2" 238 42 ...
Thanks a lot in advance!
After some research, I came up with two different solutions.
Required: Splitting the data file
Both solutions require splitting up the data file into several files categorized by a column. Therefore, I've created a short ruby script, which can be found in this gist:
https://gist.github.com/fiedl/6294424
This script is used like this: In order to split up the data file data.csv into data.Category1.csv and data.Category2.csv, call:
# bash ruby categorize_csv.rb --column 2 data.csv # data.csv # year category num_of_events_for_A num_of_events_for_B "2011";"Category1";"213";"30" "2011";"Category2";"240";"28" "2012";"Category1";"222";"13" "2012";"Category2";"238";"42" ... # data.Category1.csv # year category num_of_events_for_A num_of_events_for_B "2011";"Category1";"213";"30" "2012";"Category1";"222";"13" ... # data.Category2.csv # year category num_of_events_for_A num_of_events_for_B "2011";"Category2";"240";"28" "2012";"Category2";"238";"42" ...
Solution 1: Stacked Box Plot
Strategy: One data file per category. One column per stack. The bars of the histogram are plotted "manually" by using the "with boxes" argument of gnuplot.
Upside: Full flexibility concerning bar sizes, caps, colors, etc.
Downside: Bars have to be placed manually.
# solution1.gnuplot reset set terminal postscript eps enhanced 14 set datafile separator ";" set output 'stacked_boxes.eps' set auto x set yrange [0:300] set xtics 1 set style fill solid border -1 num_of_categories=2 set boxwidth 0.3/num_of_categories dx=0.5/num_of_categories offset=-0.1 plot 'data.Category1.csv' using ($1+offset):($3+$4) title "Category 1 A" linecolor rgb "#cc0000" with boxes, \ '' using ($1+offset):3 title "Category 2 B" linecolor rgb "#ff0000" with boxes, \ 'data.Category2.csv' using ($1+offset+dx):($3+$4) title "Category 2 A" linecolor rgb "#00cc00" with boxes, \ '' using ($1+offset+dx):3 title "Category 2 B" linecolor rgb "#00ff00" with boxes
The result looks like this:
Solution 2: Native Gnuplot Histogram
Strategy: One data file per year. One column per stack. The histogram is produced using the regular histogram mechanism of gnuplot.
Upside: Easier to use, since positioning has not to be done manually.
Downside: Since all categories are in one file, each category has the same color.
# solution2.gnuplot reset set terminal postscript eps enhanced 14 set datafile separator ";" set output 'histo.eps' set yrange [0:300] set style data histogram set style histogram rowstack gap 1 set style fill solid border -1 set boxwidth 0.5 relative plot newhistogram "2011", \ 'data.2011.csv' using 3:xticlabels(2) title "A" linecolor rgb "red", \ '' using 4:xticlabels(2) title "B" linecolor rgb "green", \ newhistogram "2012", \ 'data.2012.csv' using 3:xticlabels(2) title "" linecolor rgb "red", \ '' using 4:xticlabels(2) title "" linecolor rgb "green", \ newhistogram "2013", \ 'data.2013.csv' using 3:xticlabels(2) title "" linecolor rgb "red", \ '' using 4:xticlabels(2) title "" linecolor rgb "green"
The result looks like this:
References
