find function size mismatch in simulink

I have a simulink model initialised and run from a Matlab script. Part of the model uses a Matlab function block and to avoid expensive calls to functions not available compiled in simulink I am pre-calculating a number of things and am trying to look up values in the simulink matlab function block.

I have an Mx6 array which is a horizontal concatenation of an Mx3 array of input position vectors:

InVecs = ([x1 y1 z1]; ... [xm ym zm])

and an Mx3 array of output magnetic vectors

OutVecs = ([Bx1 By1 Bz1]; ... [Bxm Bym Bzm])

MAG = [InVecs OutVecs];

Essentially the function which takes the input vector [x1 y1 z1] and returns the output vector [Bx1 By1 Bz1] is very expensive to use in simulink as it requires some extrinsic calls. Hence I am pre-calculating all of them.

When using find in MATLAB something like: index = find(MAG(:,1:3)==vec,1), where vec is a [1x3] vector which is any of the input vectors in InVecs. MATLAB is happy to return the index of this vector. However, in Simulink, a size mismatch error is thrown: (this is for M = 501, but it may be larger or smaller)

Size mismatch (size [501 x 3] ~= size [1 x 3]).

for the line of code:

result = find(MAG(:,1:3)==relES.',1); (relES is a [3x1], hence using the transpose here)

Is there a way of using find like this in Simulink or is there another way to achieve what I'm looking for?

Thanks!

Answer 1

[Kushagr Gupta]

I would recommend looking at the ' ismember ' and ' intersect ' functions that can be used as a workaround to find the index of required row in the matrix.