Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2007
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2007

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Weird Print Result

  • To: mathgroup at smc.vnet.net
  • Subject: [mg74167] Re: [mg74122] Weird Print Result
  • From: Bob Hanlon <hanlonr at cox.net>
  • Date: Tue, 13 Mar 2007 03:40:31 -0500 (EST)
  • Reply-to: hanlonr at cox.net

Put a semi-colon after the Print statement. 

The output of--vice the action (print) of--a Print statement is a Null. You mapped Print onto a Plus with four terms and the result is the Plus of four Nulls (4 Null). Similarly,

Print /@ (A*B)

A

B

Null^2

Times of two Nulls is Null squared. Again, a semi-colon would have suppress the output of--but not the action of--the Print.


Bob Hanlon


---- Bruce Colletti <vze269bv at verizon.net> wrote: 
> Re Mathematica 5.2 under WinXP.
> 
> The code below creates the correct output, except for a strange concluding "4 Null."
> 
> What does this weird last line of output mean (list length?), why does it print, and how can it be suppressed?
> 
> Thankx.
> 
> Bruce
> 
> 
> n = 2;
> T = Array[p, {n, n}];
> X0 = Array[x, {n}];
> X = (Expand /@ (X0.MatrixPower[T, 2]));
> Print /@ X[[1]]
> 



  • Prev by Date: Re: Noob evaluation question
  • Next by Date: Re: Noob evaluation question
  • Previous by thread: Re: Weird Print Result
  • Next by thread: Re: Weird Print Result