Drexel dragonThe Math ForumDonate to the Math Forum



Search All of the Math Forum:

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.


Math Forum » Discussions » Software » comp.soft-sys.math.mathematica

Topic: Is there way to use something like Assuming with the function SIgn?
Replies: 3   Last Post: Nov 24, 2012 2:40 AM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Eduardo Mendes

Posts: 6
Registered: 11/4/12
Re: Is there way to use something like Assuming with the function SIgn?
Posted: Nov 24, 2012 2:30 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Hello

Many thanks.

Ed

On Nov 23, 2012, at 12:01 PM, Bob Hanlon <hanlonr357@gmail.com> wrote:

> "Assuming[assum, expr] evaluates expr with assum appended to
> $Assumptions, so that assum is included in the default assumptions
> used by functions such as Refine, Simplify, and Integrate."
>
> list = {1, -2, a, 3};
>
> Assuming[a < 0, Simplify[Sign[list]]]
>
> {1, -1, -1, 1}
>
> However, more compactly
>
> Simplify[Sign[list], a < 0]
>
> {1, -1, -1, 1}
>
>
> Bob Hanlon
>
>
> On Fri, Nov 23, 2012 at 3:25 AM, Eduardo Mendes <emammendes@hotmail.com> wrote:

>> Hello
>>
>> I was wondering there is something similar to what can be done with Integrate, Reduce and Limit. Something like
>>
>> list={1,-2,a,3}
>>
>> Assuming[a<0,Sign[list]]
>>
>> Mathematica returns {1,-1,Sign[a],1} and I would like to see something like {1,-1,-1,1}. Can that be done?
>>
>> Many thanks
>>
>> Ed
>>
>>

>





Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2014. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.