multiplying 2 matrices with difference sizes

Mnr
2015 12 15
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更新时间：2015 12 16
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Hello all,
I have a 12x16 matrix, M,
[ 0 0 1 0 0 0 0 -1 0 1 0 0 -1 0 0 0;0 0 0 1 0 0 1 0 0 0 0 0 -1 0 1 0;0 -1 0 0 -1 0 1 0 0 1 0 0 0 0 0 0;0 0 0 1 0 -1 0 0 0 0 1 0 0 1 0 0;0 0 1 0 0 0 0 0 -1 0 0 0 0 0 1 1;1 0 0 0 0 -1 0 0 0 1 0 0 0 0 1 0;0 0 0 1 0 0 0 -1 -1 0 0 -1 0 0 0 0;0 -1 0 0 0 -1 0 0 0 0 0 -1 0 0 0 1;1 0 0 0 0 0 1 0 0 0 0 0 0 1 0 1; 0 0 1 0 -1 0 0 0 0 0 0 -1 0 1 0 0; 0 -1 0 0 0 0 0 0 -1 0 1 0 -1 0 0 0;1 0 0 0 -1 0 0 -1 0 0 1 0 0 0 0 0]
and a 12x4 matrix P,
[0.8033 - 0.5956i -0.4224 - 0.9064i -0.7512 + 0.6600i -0.6502 - 0.7597i; -0.9993 + 0.0363i -0.9690 + 0.2473i 0.8134 + 0.5817i -0.7593 - 0.6507i; 0.6407 + 0.7678i -0.4739 - 0.8806i -0.9973 - 0.0735i 0.3493 + 0.9370i; 0.7352 + 0.6778i 0.9006 + 0.4346i -0.9478 + 0.3189i 0.9575 + 0.2883i;-0.1797 + 0.9837i 0.7638 - 0.6455i 0.6129 + 0.7902i -0.7013 + 0.7129i;0.8619 - 0.5071i -0.9843 + 0.1766i -0.3126 + 0.9499i -0.8056 + 0.5925i;-0.8067 + 0.5910i 0.4202 - 0.9074i 0.7392 - 0.6735i 0.6508 - 0.7592i;-0.8884 - 0.4590i -0.5747 - 0.8183i 0.8557 + 0.5174i 0.5900 - 0.8074i;-0.9836 + 0.1801i -0.3134 + 0.9496i 0.8707 - 0.4919i 0.6079 - 0.7940i; -0.8750 - 0.4841i -0.9497 + 0.3131i -0.8134 - 0.5817i 0.9811 - 0.1937i;-0.3354 + 0.9421i 0.5805 - 0.8143i -0.2518 + 0.9678i -0.8530 + 0.5218i;-0.6454 - 0.7638i -0.9661 + 0.2582i 0.6314 + 0.7755i 0.4847 - 0.8747i]
where the number of columns in P is the same as the number of non-zero elements in each row of M. I would like to multiply each row of M (non-zero elements) with a row of P in a fast way. Can someone help me please? Thank you!

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Roger Stafford
Roger Stafford 2015-12-16

1 个投票

A = M.';
A = (reshape((A(A~=0)),4,12).').*P; % The element-by-element product
This of course depends on each row of M having exactly four nonzero elements. Otherwise you will receive error messages. I assume you meant element-by-element multiplication.

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