[Gnuplot-info] how to plot series divided by element of series

[michael <mic...@ma...>]

Afternoon fellow GNUs!

Maybe I've missed something, being a new convert to gnuplot, but I  
wish to read in some data (NumOfCores,Seconds) and plot 2 graphs. The  
first graph is Seconds (y-axis) against NumOfCores and I've managed.  
However, the second graph is to plot the speed-up, defined on p cores  
as t(1)/t(p) where t(p) is the time taken on p cores. I can't find the  
correct syntax, eg I failed with
   plot 'timings' using 1:($2[1]/$2) with linespoints

Could somebody explain what I should be doing?

Many thanks,
Michael
www.rcs.manchester.ac.uk
www.twitter.com/mkbane_mcr