RE: Conditionals with multiple tests?
- To: mathgroup at smc.vnet.net
- Subject: [mg24119] RE: [mg24104] Conditionals with multiple tests?
- From: Wolf Hartmut <hwolf at debis.com>
- Date: Wed, 28 Jun 2000 02:11:41 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
> -----Original Message-----
> From: A. E. Siegman [SMTP:siegman at stanford.edu]
To: mathgroup at smc.vnet.net
> Sent: Tuesday, June 27, 2000 6:52 AM
> To: mathgroup at smc.vnet.net
> Subject: [mg24104] Conditionals with multiple tests?
>
> Let's say I want to assign values to three variables p1, p2, p3 that
> will depend on five different (and nonoverlapping) tests test1 to test 5.
>
> One way to do this is obviously
>
> p1 = Which[test1, value11, test2, value12, . . . ]
> p2 = Which[test1, value21, test2, value22, . . . ]
> p3 = Which[test1, value31, test2, value32, . . . ]
>
> But a more compact and (for me anyway) neater approach is
>
> Which[test1, p1=value11; p2=value21; p3=value31,
> test2, p1=value21; p2=value22; p3=value32,
> test3, . . .
> test4, . . .
> test5, . . . ]
>
> Is this form legal? That is, can one use:
>
> Which[test1, expr1, test2, expr2, . . .]
>
> where expr1, expr2, . . . may be compound expressions?
>
> (I would say that The Mathematica Book is not at all clear on this
> point, as regards either Which[] or If[].)
>
> If not, is there a legal way to implement the basic objective?
>
[Wolf Hartmut]
absolutely legal ("everything is an expression"). Perhaps you also should
consider the possibility
{p1, p2, p3} =
Which[test1, {value11, value21, value31},
test2, {value12, value22, value32}, ...]