Re: Piecewise inside a Module or Block, I don't understand this
- To: mathgroup at smc.vnet.net
- Subject: [mg83300] Re: Piecewise inside a Module or Block, I don't understand this
- From: "W. Craig Carter" <ccarter at mit.edu>
- Date: Sat, 17 Nov 2007 05:17:25 -0500 (EST)
- References: <fhjs9v$4vg$1@smc.vnet.net> <473DA496.5050509@gmail.com>
>> a[c_, d_] :=
>> Module[{e, f}, e = d^2; f = c^2;
>> Return[Piecewise[{e, 0 < x < 1/2}, {f, 1/2 < x <= 1}]]];
>> a[1,2] (*doen't return what I had anticipated*)
>
> All this is just about a syntax error you made.
>
> First, note that, as posted, none of the above examples works: they both
Cher Jean-Marc,
I don't get an error when I cut and paste this expression.
Math6.01
And, the posted work-around works just fine:
aAlt[c_, d_] :=
Module[{e, f}, e = d^2; f = c^2;
{{e, 0 < x < 1/2}, {f, 1/2 < x <= 1}}];
Piecewise@aAlt[1,2]
Note, that this seems to be peculiar to Piecewise: e.g,
a[c_, d_] :=
Module[{e, f}, e = d^2; f = c^2;
Return[MyUnAssignedFunction[{e, 0 < x < 1/2}, {f, 1/2 < x <= 1}]]];
` a[1,2]
works as I hoped.
PS: My goal here was to write a function that made a calculation of the
bounds, and then returned a piecewise function of x that had the bounds
as explicitly calculated.