How to multiply two matrices together?
2 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Tristan
le 28 Oct 2013
Réponse apportée : Andrei Bobrov
le 28 Oct 2013
I need to create a new matrix C which is the sum of A multiplied by B(1)=1.7 and B(2)=1.1
>> A = [12 62 93 -8 22; 16 2 87 43 91; -4 17 -72 95 6]
A =
12 62 93 -8 22
16 2 87 43 91
-4 17 -72 95 6
>> B=[1.7 1.1]'
B =
1.7000
1.1000
I could just do:
>> A*1.7+A*1.1
ans =
33.6000 173.6000 260.4000 -22.4000 61.6000
44.8000 5.6000 243.6000 120.4000 254.8000
-11.2000 47.6000 -201.6000 266.0000 16.8000
but the real B I'm working with has too many numbers to just type them all
I tried bsxfun but it doesn't work
>> C=bsxfun(@times,A,B)
Error using bsxfun Non-singleton dimensions of the two input arrays must match each other.
0 commentaires
Réponse acceptée
Azzi Abdelmalek
le 28 Oct 2013
Modifié(e) : Azzi Abdelmalek
le 28 Oct 2013
Notice that A*B(1)+A*B(2)+...+A*B(n) is equal to A*(B(1)+B(2)+...B(n))
A = [12 62 93 -8 22; 16 2 87 43 91; -4 17 -72 95 6];
B=[1.7 1.1]';
C=A*sum(B)
2 commentaires
Azzi Abdelmalek
le 28 Oct 2013
A = [12 62 93 -8 22; 16 2 87 43 91; -4 17 -72 95 6];
B=[1.7 1.1]';
s=cell2mat(arrayfun(@(x) cos(A*x),B','un',0))
[n,m]=size(A);
p=numel(B);
C=sum(reshape(s,n,m,p),3)
Plus de réponses (1)
Voir également
Catégories
En savoir plus sur Operators and Elementary Operations dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!