multiplying a matrix
Afficher commentaires plus anciens
i have a matrix
A=[3 5 7
5 6 0
5 9 4]
i want to square each element and add along row wise and display
for ex
3^2+5^2+7^2
ans is 89
so i need as
89
71
122
pleas guide
15 commentaires
Chandra Kurniawan
le 10 Jan 2012
3^2+5^2+7^2 = 83, right?
5^2+6^2+0^2 = 61, right?
FIR
le 10 Jan 2012
FIR
le 10 Jan 2012
Chandra Kurniawan
le 10 Jan 2012
what size of q?
FIR
le 10 Jan 2012
Andrei Bobrov
le 10 Jan 2012
sum(q(:,1:20).^2)
Walter Roberson
le 10 Jan 2012
You require summing terms that are individually q^2ir . You cannot raise a matrix (e.g., q is 2 x 99) to a vector power (e.g., r is 1:20)
Walter Roberson
le 10 Jan 2012
andrei, notice that both i and r also occur in the exponent.
Chandra Kurniawan
le 10 Jan 2012
q = rand(2,20);
r = 1 : 20;
n = 2;
for i = 1 : n
rsl{i} = q(i,:).^2 .* i .* r;
end
Is this, right?
Andrei Bobrov
le 10 Jan 2012
so?
i1 = 1:2;
r = 1:20;
out = sum(q.^(2*i1.'*r))
FIR
le 10 Jan 2012
Chandra Kurniawan
le 10 Jan 2012
Okay. Glad to help you.
Walter Roberson
le 10 Jan 2012
andrei, you cannot raise a matrix to a vector. You can raise a matrix to a scalar or a scalar to a matrix.
FIR
le 10 Jan 2012
Andrei Bobrov
le 10 Jan 2012
i1 = 1:2;
r = 1:20;
out = sum(q.^2.*(i1.'*r))
Réponse acceptée
Plus de réponses (1)
Andrei Bobrov
le 10 Jan 2012
B = sum(A.^2,2);
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