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: declaring variables
Replies: 3   Last Post: Sep 16, 1996 10:33 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Victoria Steblina

Posts: 18
Registered: 12/7/04
Re: declaring variables
Posted: Sep 13, 1996 1:00 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

dh61@rs3.hrz.th-darmstadt.de (Burkhardt Goedde) wrote:

>Dear math users,
>just a simple problem, but I got no answer from thew book.
>Re[x + I y] gives
>Re[x + I y]
>whereas
>Re[2 + 3 I]
>gives 2
>How could I tell Mathematica that x and y are real numbers?


There is a package <<Algebra`ReIm` that lets you specify that given
variables are purely real. Try the following:

In[5]:= Needs["Algebra`ReIm`"]

Im[x]^=0;

Im[y]^=0;

Re[x + I y]

Im[x + I y]

Out[8]= x
Out[9]= y

The up definitions make the assignment associated with x and y rather
than
with Im...

Hope this helps
Vicki

________________________________________________________________________

Victoria Steblina Email: vvs124@rsphy1.anu.edu.au
Optical Sciences Centre Tel: 61 6 249 5129
Australian National University Fax: 61 6 249 5184








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.