Solving Complex Matrix Operations

I have tried everything!

Answer 1

[Fabio Freschi]

You can do this in a for loop or using arrayfun

% your A vector
A = rand(1,1001);  % dummy vector

% calculation of the matrix B
B = arrayfun(@(a)[cos(-a) sin(-a) 0; -sin(-a) cos(-a) 0; 0 0 1],A,'UniformOutput',false);

Than you can access each matrix using the {} indexing, e.g. the first matrix is

B{1}

etc

[Missael Hernandez]

u_body=[y(:,1)];
v_body=[y(:,2)];
w_body=[y(:,3)];

phi=[y(:,7)];
theta=[y(:,8)];
psi=[y(:,9)];

Rz = arrayfun(@(a)[cosd(-a) sind(-a) 0; -sind(-a) cosd(-a) 0; 0 0 1],psi,'UniformOutput',false);
Ry = arrayfun(@(a)[cosd(-a) 0 -sind(-a) ; 0 1 0 ; sind(-a) 0  cosd(-a)],theta,'UniformOutput',false);
Rx = arrayfun(@(a)[1 0 0; 0 cosd(-a) sind(-a) ; 0 -sind(-a) cosd(-a)],phi,'UniformOutput',false);

Ok so phi, theta, and psi are three 1001X1 column vectors. I want to take phi_(1,m), theta_(1,m), and psi_(1,m), and plug them into Rx, Ry, and Rz respectively. Then I want to multiply those results to obtain a 3X3 matrix. How do I do that?

[Fabio Freschi]

% choose an index
index = 1;

% get the rotation matrix
R = Rx{index}*Ry{index}*Rz{index};

is this what you want?

[Missael Hernandez]

Yes but I want to do it for all 1001 values at the same time

[Fabio Freschi]

Add

R = cellfun(@(Rx,Ry,Rz)Rx*Ry*Rz,Rx,Ry,Rz,'UniformOutput',false);

[Missael Hernandez]

what if I want to multiply each individual R by another vector?