Re: [Gnuplot-info] PlottingArrays

[Ethan M. <eam...@gm...>]

On Friday, 16 September 2022 05:21:16 PDT Geoff Kaniuk wrote:
> Thank you all for the swift replies. This made me realise that my 
> looped plot example produces separate plots for each array, but I wanted 
> all curves in 1 plot.
> 
> Using the eval clue I have come up with a solution looking like this:
> 
> STEP1. create a function curves(n)
> 	to generate the string  "ab1 w lp, ab2 w lp"
> 	( I wonder if this what Alan Corey meant by search & replace)
> 
> STEP2.
> 	curves = curves(2)
> 	plotcurves = "plot ".curves
> 	eval(plotcurves)
> 
> Using sprintf to get plotcurves also worked. One slight issue is that I 
> had missed a space after the comma separating the plot elements. So  the 
> generated string  "ab1 w lp,ab2 w lp" failed, with plot trying to treat 
> it as the name of a single file. However plot ab1 w lp,ab2 w lp is fine.
> 	
> Although this is a solution for a handful of arrays, is this really the 
> only way?

I don't think you can do better than that in version 5.2.

The development version of gnuplot supports a larger set of array
operations including treating them as unitary variables for the
purpose of passing an array to, or returning an array from, a function.

Here is a script that works in 5.5 but not in 5.2:

###
array ab1 = [1,1,1]
array ab2 = [2,2]
array ab5 = [5,5]
array ab67 = [67,67]
list = ""
do for [i = 1:99] {
    name = sprintf("ab%d",i)
    if (exists(name)) {
        list = list." ".name
    }
}
print "Now I will plot: ", list
plot for [name in list] value(name) with lp
###

Version 5.2 understands what that script attempts to do but
prints an error "unsupported array operation".

	Ethan