Re: copying values of entries between matrices
- To: mathgroup at smc.vnet.net
- Subject: [mg78026] Re: [mg77952] copying values of entries between matrices
- From: DrMajorBob <drmajorbob at bigfoot.com>
- Date: Thu, 21 Jun 2007 05:54:20 -0400 (EDT)
- References: <4034280.1182335833295.JavaMail.root@m35>
- Reply-to: drmajorbob at bigfoot.com
Clear[lowerDiagonal]
lowerDiagonal[m_?MatrixQ] :=
Flatten[m[[#, Range@#]] & /@ Range@Length@m]
entMatr = RandomReal[{0, 1}, {18, 18}];
lowerDiagonal[entMatr] // Length
171
Bobby
On Wed, 20 Jun 2007 04:37:37 -0500, text.tex <Clausenator at gmail.com> 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!
> Thanks,
> Claus
>
> This is what I tried:
>
> <pre>
> (* initialize entMatr *)
> entMatr = Table[Subscript[m, i, j], {i, 18}, {j, 18}];
>
> (* fill the lower left half of entMatr with some values *)
> For[i = 1, i < 18 + 1, i++,
> For[j = i, j < 18 + 1, j++,
> entMatr[[j, i]] = i
> ]
> ]
>
> (* initialize dOneCol *)
> dOneCol = Table[Subscript[n, x], {x, 171}];
>
> (* attempt to copy the values from entMatr to dOneCol *)
> q = 0;
> For[k = 1, k < 18 + 1, k++,
> For[p = k, p < 18 + 1, p++,
> dOneCol[[q]] = entMatr[[p,k]]
> q++
> ]
> ]
> dOneCol
> </pre>
>
>
>
-- =
DrMajorBob at bigfoot.com