multiplying a matrix
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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 Comments
Chandra Kurniawan
on 10 Jan 2012
3^2+5^2+7^2 = 83, right?
5^2+6^2+0^2 = 61, right?
FIR
on 10 Jan 2012
FIR
on 10 Jan 2012
Chandra Kurniawan
on 10 Jan 2012
what size of q?
FIR
on 10 Jan 2012
Andrei Bobrov
on 10 Jan 2012
sum(q(:,1:20).^2)
Walter Roberson
on 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
on 10 Jan 2012
andrei, notice that both i and r also occur in the exponent.
Chandra Kurniawan
on 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
on 10 Jan 2012
so?
i1 = 1:2;
r = 1:20;
out = sum(q.^(2*i1.'*r))
FIR
on 10 Jan 2012
Chandra Kurniawan
on 10 Jan 2012
Okay. Glad to help you.
Walter Roberson
on 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
on 10 Jan 2012
Andrei Bobrov
on 10 Jan 2012
i1 = 1:2;
r = 1:20;
out = sum(q.^2.*(i1.'*r))
Accepted Answer
More Answers (1)
Andrei Bobrov
on 10 Jan 2012
B = sum(A.^2,2);
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