Gnuplot histogram example

histogram.plt

#!/gnuplot
#    
# Histogram of compression ratio distribution
#
set terminal postscript enhanced landscape
set output "histogram.ps"
set size ratio 0.5
set key top right
set xlabel "Compression ratio"
set ylabel "Number of files"
set style fill solid 1.0 border -1
set datafile separator ","
binwidth=0.02 # Adjust according to distribution of values in data file 
set boxwidth binwidth
bin(x,width)=width*floor(x/width) + binwidth/2
plot "./test_derived.csv" using (bin($2,binwidth)):(1.0) smooth freq with boxes t ""
# EOF

test_derived.csv