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: How to remove the "0." from "0. + 1.41774i"
Replies: 9   Last Post: Jun 22, 2013 8:41 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Christoph Lhotka

Posts: 41
Registered: 3/2/10
Re: How to remove the "0." from "0. + 1.41774i"
Posted: Jun 22, 2013 8:41 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Hello,

On 06/22/2013 10:21 PM, Richard Fateman wrote:
> On 6/22/2013 8:40 AM, Christoph Lhotka wrote:
>> Dear mathgroup,
>>
>> there is indeed a very elegant solution to these kind of problems.
>> It took
>> me some while (looking up the documentation center) but I think this
>> works fine:

> Well, there are lots of little problems with this solution, some of
> which have to do
> with the semantics of N, so that 1/2+2I looks like floats, and
> 2^5000+2I looks like
> 1.4124...x10^1505 + 0. I. with a red box around the 0.
>


of course my definition of format did not take your cases into account (it was meant to work on realistic approximate complex numbers), but for sure you can modify the definition to satisfy your needs.

> but also there is an issue that FullForm[%] is peculiar.
>


FullForm works as expected, also pattern matching works (in terms of the
interpreted expression).

> So the idea of changing the display format in $Post processing is a
> possibility,
> it rapidly becomes less elegant if you expect it to cover every
> eventuality, and
> probably not possible if you want FullForm to work.
> RJF
>


I think, that you did not see the main point. It is not the definition of format it is the mechanism that allows to implement any output format in terms of interpreted expressions.

Here I merge your approach of a previous post with mine to work in a more
elegant way:

In[1]:= format[c_Complex]:=
Interpretation[
Re[c]+i Im[c],c]

In[2]:= $Post=#/.c_Complex:>format[c]&
Out[2]= #1/. c_Complex:>format[c]&

In[3]:= c1=1/2+2I
Out[3]= 1/2+2 i

In[4]:= c1^2
Out[4]= -(15/4)+2 i

In[5]:= c1=2^5000+2I;

In[6]:= Im[c1]
Out[6]= 2

In[7]:= FullForm[0.+1.i]
Out[7]//FullForm= Plus[0.`,Times[1.`,i]]

In[8]:= c1/.c_Complex:>Im[c]
Out[8]= 2

In[9]:= Clear[$Post]

I like this!





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.