I am currently writing a matlab function that I have embedded in a simulink model.

Now when compiling I get the error message that simulink expect indx_p11 to be a scalar but it is a [:?,1] where I use this to extract data slices from the matrix. Similar error messages exist for the other indx_p variables.

Initially the lines with indx_p11 = zeros(1,1) was not present as I hoped to preallocate them and hence fix the dimensions. The error messages were exactly the same.

I have no idea how to fix this.

Can somebody please help?

P.S.: Inside matlab it works as intended. Simulink seems to be stricter here but I don’t know how to solve it.

function indx = GetMtrxInterval(temp,press,property_matrix)

indx = zeros(4,1);
indx_p11 = zeros(1,1);
indx_p12 = zeros(1,1);
indx_p21 = zeros(1,1);
indx_p22 = zeros(1,1);

press_intervals_idx = find(diff(property_matrix(:,2))); % contains indexes of pressure values after which the pressure changes in properties STOFF table


if press >= min(property_matrix(:,2)) && press <= max(property_matrix(:,2))
    %find slice of table with max(pressure<press)
    indx_p12 = find(press<property_matrix(:,2),1) - 1;
    indx_p11 = press_intervals_idx(find(indx_p12==press_intervals_idx,1)-1)+1;

    %find slice of table with min(pressure>press)
    indx_p21 = indx_p12 + 1;
    indx_p22 = press_intervals_idx(find(indx_p12==press_intervals_idx,1)+1);

    %find temperature interval for lower pressure slice
    if temp >= min(property_matrix(indx_p11:indx_p12,1)) && temp <= max(property_matrix(indx_p11:indx_p12,1))
        %find temperature interval for lower pressure slice
        if temp == property_matrix(indx_p11,1)
            indx_t11 = indx_p11;
            indx_t12 = indx_t11+1;
        else
            indx_t12 = indx_p11 + find(temp<=property_matrix(indx_p11:indx_p12,1),1) - 1;
            indx_t11 = indx_t12-1;
        end
    end


indx = [indx_t11; ...
    indx_t12; ...
    indx_t21; ...
    indx_t22];
end