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]] >