Re: 8 bit and FactorInteger ...

• To: mathgroup at smc.vnet.net
• Subject: [mg14527] Re: 8 bit and FactorInteger ...
• From: Paul Abbott <paul at physics.uwa.edu.au>
• Date: Thu, 29 Oct 1998 04:33:25 -0500
• Sender: owner-wri-mathgroup at wolfram.com

```Jens-Peer Kuska wrote:

> FactorIntegerForm[faci_]:=
>    DisplayForm[Infix[SuperscriptBox[Sequence @@ #] & /@
> faci,"\[Times]"]]

Nice. So things like

FactorInteger[10!]//FactorIntegerForm

work. Two questions:

[1] What is the easiest/best way to get the result back as a number
(i.e. remove the DisplayForm wrappers, etc)?

[2] Is there an easy way to associate FactorForm with FactorInteger
automatically?

Note however that

[1] if the exponent is 1 it is still printed.

[2] your code does not handle GaussianIntegers, e.g.,

FactorInteger[25,GaussianIntegers->True]//FactorIntegerForm

Here is a different approach by Paul Wellin with some additions by Stan
Wagon which handles unit exponents and Complex factors.  I expect that
you could extend your code (which makes nice use of Infix) to handle
the Complex case as well.

FactorForm[{}] = 1;

FactorForm[l_] :=  (
temp = RowBox[{#, "\[CenterDot]"}] &  /@
(MapThread[
If[#2 == 1,
If[Head[#1]===Complex,
StringJoin["(", ToString[#1], ")"],
ToString at #1], SuperscriptBox[ToString at #1, #2]]&,
Transpose[l]]);
SequenceForm@@DisplayForm/@
ReplacePart[temp, Drop[temp[[-1,1]],-1],{{-1,1}}])

FactorForm[FactorInteger[12333000, GaussianIntegers->True]]

Note that this is still not perfect: if you use TraditionalForm for
output (as I do) the String conversion changes \[ImaginaryI] into I.

Cheers,
Paul

____________________________________________________________________
Paul Abbott                                   Phone: +61-8-9380-2734
Department of Physics                           Fax: +61-8-9380-1014
The University of Western Australia           Nedlands WA  6907
mailto:paul at physics.uwa.edu.au AUSTRALIA
http://www.physics.uwa.edu.au/~paul

God IS a weakly left-handed dice player
____________________________________________________________________

```

• Prev by Date: nonlinear regress on multiple data sets?
• Next by Date: beep after calculation
• Previous by thread: nonlinear regress on multiple data sets?
• Next by thread: beep after calculation