Re: Weird Print Result

*To*: mathgroup at smc.vnet.net*Subject*: [mg74154] Re: Weird Print Result*From*: dh <dh at metrohm.ch>*Date*: Mon, 12 Mar 2007 22:13:30 -0500 (EST)*Organization*: hispeed.ch*References*: <et36rq$qgu$1@smc.vnet.net>

Hi Bruce, consider your last line: Print /@ X[[1]]. Presumably you wanted: Print @ X[[1]] or Print[ X[[1]] ]. What you did, is to map Print on the first level of X[[1]]. As the output of Print is Null and as the Head of X[[1]] is Plus, you created: Plus[Null,Null,Null,Null]. This gives 4 Null, correct? Daniel Bruce Colletti 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]] >