Re: copying values of entries between matrices

*To*: mathgroup at smc.vnet.net*Subject*: [mg77985] Re: [mg77952] copying values of entries between matrices*From*: Sseziwa Mukasa <mukasa at jeol.com>*Date*: Thu, 21 Jun 2007 05:33:10 -0400 (EDT)*References*: <200706200937.FAA10111@smc.vnet.net>

On Jun 20, 2007, at 5:37 AM, text.tex wrote: > Hi, > here is my problem: > I have a 18x18 matrix called entMatr. > I want to copy the values of the elements of the lower left half of > entMatr into a 171x1 matrix called dOneCol. > I had tried a 3-nested loop for copying the values from entMatr to > dOneCol; the current version where I tried to replace the loop over > the rows of dOneCol with a counter q produces a result, however the > result is not what I want... > > I'd greatly appreciate any pointers how to get this working! One immediate problem is that the first element of a list in Mathematica has index 1 not 0. The code you sent looks like a straightforward translation of C code, which is not generally a good match to Mathematica style. Here's an alternative way to generate entMatr; entMatr=Array[If[#2<=#1,#2,Subscript[m,#1,#2]]&,{18,18}] You can extract the matrix elements as follows: dOneCol=Flatten[Table[entMatr[[j,i]],{i,18},{j,i,18}],1] Regards, Ssezi

**References**:**copying values of entries between matrices***From:*"text.tex" <Clausenator@gmail.com>