How to multiply vectors not the same size to create 3d tensor?

Hi! I have a function that receives a few scalars along with a few vectors that calculates a certain value. I use the following for loop in order to fill in a 3D tensor that contains all results from all possible combinations of these three vectors:

Z3 = zeros(length(T), length(Rtry), length(theta));
x = 0;
y = 0;
z = 0;
for tt = t_obs
    x = x+1;
    y = 0;
    for rr = Rtry
        y = y+1;
        z = 0;
        for mm = mu
            z = z + 1;
            Z3(x, y, z) = toint(3, Rtry(y), t_obs(x), RT1, t_obs, dRdtT1, mu(z));
        end
    end
end

I want to vectorize this code but I'm having some trouble understanding how. I wrote this line

Ztry = toint(3, Rtry, t_obs, RT1, t_obs, dRdtT1, mu);

but I get the following error

Error using  * 
Incorrect dimensions for matrix multiplication. Check that the number of columns in the first matrix matches the
number of rows in the second matrix. To operate on each element of the matrix individually, use TIMES (.*) for
elementwise multiplication.

that occures in the following function:

function getTime = getShockFrameTime(t, r, mu)
c = 29979245800; %cm/s
getTime = t + r*mu/c;
end

with t, r and mu being the vectors t_obs, Rtry and mu, respectively.

The vectors are different lengths and I want it to return a 3D tensor, not a vector.

Thank you in advance :)

Answer 1

[Voss]

One thing you can do is reshape your vectors as desired and use .*, for example:

t_obs = [1 2 3]*1e-6;
Rtry = [4 5 6 7]*1e2;
mu = [8 9];

result = getShockFrameTime(t_obs, Rtry, mu);

size(result)

ans = 1×3

3 4 2

disp(result)

(:,:,1) =

   1.0e-05 *

    0.1107    0.1133    0.1160    0.1187
    0.2107    0.2133    0.2160    0.2187
    0.3107    0.3133    0.3160    0.3187


(:,:,2) =

   1.0e-05 *

    0.1120    0.1150    0.1180    0.1210
    0.2120    0.2150    0.2180    0.2210
    0.3120    0.3150    0.3180    0.3210

function getTime = getShockFrameTime(t, r, mu)
c = 29979245800; %cm/s
getTime = reshape(t,[],1) + reshape(r,1,[]).*reshape(mu,1,1,[])/c;
% reshaping like this, size(getTime) is [numel(t) numel(r) numel(mu)]
% adjust as necessary
end

[Voss]

@Noya Linder: Did this answer work for you?