Re: Is there any reason why it can not take a list of numbers ?

[sfeam <sf...@us...>]

On Saturday, 17 September 2016 08:09:09 PM pl...@pi... wrote:
> On 17/09/16 18:12, sfeam wrote:
> > gnuplot> set for [a in "11 13 17"] arrow from a,0 to a,1
> 
> 
> Many thanks Ethan. , I have to admit I did not try that since I consult 
> the doc when I don't know syntax and do not waste time doing other 
> things than what is documented  in the wild  hope of discovering 
> undocumented features.
> 
> So we have a documentation bug , that syntax is not proposed for intvar 
> and apparently it should be.

Not exactly.  It's more of an unintended (but useful) consequence of 
promotion from string to integer wherever the program knows that a 
number is expected.

In the above example a is a string variable not an integer variable.
But the "set arrow" command is looking for a number, not a string,
so it does the conversion silently.   Just as the following both work
    plot foo lt 2
    plot foo lt "2"

This does _not_ work for floating point number however.
That's why I think it might be a good idea to allow iteration over
the elements in an array.  Then you could have something like
array value[3] = [1.11, 2.22, 3.33]

  plot for [V in value] f(V)

> I did do a fair bit of searching trying to find a work around or a trick 
> and did  not find anything. So it looks like most people like me believe 
> what they read and are not profiting form this excellent feature.
> 
> Regards.  Peter.