Re: Evaluating expressions in pure functions
- To: mathgroup at smc.vnet.net
- Subject: [mg28462] Re: Evaluating expressions in pure functions
- From: "Allan Hayes" <hay at haystack.demon.co.uk>
- Date: Fri, 20 Apr 2001 04:24:12 -0400 (EDT)
- References: <9bm576$j3j@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Max,
Here are some techniques:
Evaluate/@(Exp[2*3*#]&)
E^(6*#1) &
{2*3+4,#}&/.x_Times:>RuleCondition[x]
{6+5,#1}&
{2*3+4*5,#}&/.x_Times:>RuleCondition[x]
{6+20,#1}&
[
(!) But note that RuleCondition is an internal symbol and is barely
documented:
?RuleCondition
RuleCondition is an internal symbol.
RuleCondition[a] is equivalent to RuleCondition[a,True]
]
To avoid evaluationg both the products, we can use
ReplacePart[{2*3+4*5, #}&,{2*3+3*4, #}&[[1,1,1]], {1,1,1}]
{6+4 5,#1}&
--
Allan
---------------------
Allan Hayes
Mathematica Training and Consulting
Leicester UK
www.haystack.demon.co.uk
hay at haystack.demon.co.uk
Voice: +44 (0)116 271 4198
Fax: +44 (0)870 164 0565
"Max Ulbrich" <ulbrich at biochem.mpg.de> wrote in message
news:9bm576$j3j at smc.vnet.net...
> Hi,
>
> I have the following problem:
> I have a pure function with a product of numbers in it.
> Mathematica doesn't evaluate the product:
>
> Exp[2*3*#]&
>
> I just want to get
>
> Exp[6*#]&
>
> How can I make Mathematica do this?
> Thanks,
>
> Max
>
>