Plotting datafile with abbreviated values with gnuplot

Question

I have a gnuplot datafile that looks like this:

 1  4810   582   573   587 
 2    99k   67k   56k   40k
 3   119k   82k   68k   49k
 4   119k   81k   68k   49k
 5   120k   81k   65k   45k
 6   121k   82k   65k   44k
 7   124k  106k   97k   86k
 8   128k  134k  131k  131k
 9   128k  130k  131k  135k
10   129k  133k  130k  132k

First column will be on the X-axis labeled as "Time", the rest are the different interrupt values with respect to time (i.e. IRQ1, IRQ2, IRQ3, IRQ4)

The problem when generating a plot with this is that gnuplot does not seem to interpret the abbreviated values with the K suffix as numbers in the thousands, but instead as raw values such as 99, 67, 119, etc. Thus the lines will jump from around 5000 at time 1 and drop to around 100 in the graph.

Are there any options to tell gnuplot to automatically interpret abbreviated values and plot them accordingly?

F. Knorr F. Knorr · Accepted Answer · 2015-11-03T20:26:44

I think there is no direct way of telling gnuplot of how to interpret the input in this case.

You can, however, write your own function that converts the string-input to numbers

check(x)=(pos=strstrt(x,"k"),\
    pos > 0 ? real(substr(x,1,pos-1))*1000  : real(x))

The function check first determines the position of the letter 'k' in the input. (The function strstrt returns '0' if the input x does not contain the letter 'k'.)
If the input contains the letter 'k', take the input, discard the last letter, convert the remaining part to a number and multiply it by 1000. If the input does not contain 'k', return the input

Now you can plot the data file (assuming its name is test):

plot 'test' u 1:(check(stringcolumn(2))) w l

This should do the job!

Plotting datafile with abbreviated values with gnuplot

2 Answers