Copying a small quadratic matrix into a bigger quadratic matrix
Subject: Copying a small quadratic matrix into a bigger quadratic matrix
From: Prof. Dr. Eberhard Franz
Date: Thu, 15 Apr 2010 17:43:10 +0200
Thank you, it works perfectly.
-----Urspr?ngliche Nachricht-----
Von: Leo Butler [mailto:l.butler at ed.ac.uk]
Gesendet: Sonntag, 11. April 2010 19:04
An: Eberhard Franz
Cc: maxima at math.utexas.edu
Betreff: Re: [Maxima] Copying a small quadratic matrix into a bigger quadratic matrix
On Thu, 8 Apr 2010, Eberhard Franz wrote:
< Hi everybody,
<
< I just want to copy e.g. a 4x4 matrix into e.g. 6x6 at a certain location. I
< found that this could be done via two nested loops:
<
< for i:3 thru 6 step 1 do for j:3 thru 6 step 1 do Kge2_ex[i,j]:Kge2[i-2,j-2];
<
< Is there any smarter way?
genmatrix with a lambda function can do the trick,
genmatrix(lambda([i,j], if i<5 and j<5 then A[i,j] else 0), 6,6);
or some variation on this.
Leo
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