Re: Variables in Iterator limits?
- To: mathgroup at smc.vnet.net
- Subject: [mg109629] Re: Variables in Iterator limits?
- From: "Kurt TeKolste" <tekolste at fastmail.net>
- Date: Sun, 9 May 2010 07:49:01 -0400 (EDT)
It would appear that in evaluating
Show[lines]/.testValues
you are first evaluating Show[lines] with no assigned value for kmax,
getting the error message and the full form of Show[lines] and then
evaluating that with kmax assigned, resulting in the graph
For comparison try Show[lines/.testValues]
ekt
On Sat, 08 May 2010 07:05 -0400, "AES" <siegman at stanford.edu> wrote:
> If I execute the following lines, I get the graphic that I want:
>
> x; Remove["Global`*"];
>
> lines := Graphics[ Table[ Line[{{k 10/kmax,-1},
> {k 10/kmax,1}}], {k,1,kmax}]]
>
> km = 30; Show[lines]
>
> If I execute the following lines, I get exactly the same graphic, all OK,
>
> x; Remove["Global`*"];
>
> lines := Graphics[ Table[ Line[{{k 10/kmax,-1},
> {k 10/kmax,1}}], {k,1,kmax}]]
>
> testValues = {kmax->30}; Show[lines] /. testValues
>
> -- except that I also get a beep, and an error msg in the Messages
> window:
>
> "Iterator {k,1,kmax} does not have appropriate bounds"
>
> (but no little red square in the graphics output cell).
>
> Same thing happens in the /. case if I do the two tests in reverse order.
>
> Seems like another annoying little Mathematica "gotcha" to me . . . ?
>
>