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Re: question on changing 'type' of numbers

• To: mathgroup at smc.vnet.net
• Subject: [mg69490] Re: question on changing 'type' of numbers
• From: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>
• Date: Thu, 14 Sep 2006 06:55:18 -0400 (EDT)
• Organization: Uni Leipzig
• References: <ee8h72$j38$1@smc.vnet.net>

Hi,

a) Mathematica has no types, it has patterns
b) what may Round[], Floor[] and the Ceiling[] 
function
   do ? Convert a _Real into an _Integer ? in a 
way
   that give you the full access how the 
fractional term
   handled

Regards
  Jens


"Nasser Abbasi" <nma at 12000.org> schrieb im 
Newsbeitrag news:ee8h72$j38$1 at smc.vnet.net...
|I think of a the Head of expression as its 
'type'.
|
| One is supposed to be able to use Apply[f,expr] 
to change head of expression
| to f.
|
| But Why can't I use this to change the head of a 
Real number to Integer?
|
| In[122]:=
| Remove["Global`*"]
| x = 0.1
| Head[x]
|           -------------->Real
| Apply[Integer,x]
| Head[x]
|        ------------------->Real. I was expecting 
Intger
| x = Integer[x]
| Head[x]
|      ----------------> Now it says Integer
|
| any idea?
|
| ofcourse the question as to what should happen 
to the value of the variable
| if for example I change the head of 0.5 from 
Real to Integer is another
| matter. It seems in this case x remained 0.1 but 
only the head said Integer
|
| x
| ----->Integer[0.1]
|
| Now sure what the above really means :)
|
| Nasser
|