Re: Recalculating values in tables?
- To: mathgroup at smc.vnet.net
- Subject: [mg63905] Re: Recalculating values in tables?
- From: Peter Pein <petsie at dordos.net>
- Date: Sat, 21 Jan 2006 01:50:55 -0500 (EST)
- References: <dqqbtt$lu1$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
AES schrieb:
> If I'm evaluating a table with something like
>
> Table[ {initialExpressions; f1, f2, Sqrt[(f1-f2)/(f1*f2)}, {iterator} ]
>
> where f1, f2, f3 are slow-to-evaluate functions (possibly with
> explicit variables, which will be the same for all three calls to the
> f's), I'm tempted to assume that Mathematica will be smart enough to
> evaluate f1, f2 and f3 just once, not three times, for each line in the
> Table. Is this low risk?
>
> Or should I always take the messier of route of coding these functions
> explicitly in my initialExpressions using something like
>
> Table[ { initialExpressions;
> g1=f1;
> g2=f2;
> g3=f3;
> g1, g2, Sqrt[(g1-g2)/(g1*g2)}, {iterator} ]
>
> Just wondering how far to trust Mathematica in situations like this?
>
Hi AES,
if I understand you correctly, you want
Table[
Module[{g1,g2,g3},
initialExpressions;
{g1,g2,g3}={f1,f2,f3};
{g1, g2, Sqrt[(g1-g2)/(g1*g2)]}],
{iterator}]
?
Peter