Using pagemtimes multiplying from left and right side

I have a 3D array I need to multiply on left and right sides by a constant 3x3 matrix, take a cholesky decomposition and multiply it by a random vector, I am trying to avoid for loops. The arrays are P 6x6xN and F 3x6. The equivalent for loop multiplication is
for i=1:length(Pf)
w = chol(Fn*Pf(:,:,i)*Fn')*randn(3,1);
out(:,i) = out(:,i) + w;
end

Respuestas (1)

You can use pagemtimes to perform both multiplications but, since chol accept only matrices (2D arrays) as arguments, you'll still need a loop. Try the code below:
n = size(Pf, 3);
aux = pagemtimes(Fn, Pf);
aux = pagemtimes(aux, Fn');
for i = 1:n
aux (:,:,i) = chol(aux(:,:,i));
end
aux = pagemtimes(aux, rand(3,1,n));
If you desire retrieve the steps taken, you may avoid overwriting the aux variable renaming the sucessive results as aux1, aux2 etc, or other names of your preference.

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Productos

Versión

R2020b

Preguntada:

el 3 de Mayo de 2021

Respondida:

el 29 de Ag. de 2022

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