MATLAB: Array index in symsum

Question

Hi,

I try to define this function

syms k;
error = @(c, r)symsum((abs(Data(k,:)-c)-r).^2,k,1,119);

Where Data is a 119×3 matrix, and c and r are 1×3. I get this error:

Error using sym/subsindex (line 737)
Invalid indexing or function definition. When defining a function, ensure that
the arguments are symbolic variables and the body of the function is a SYM
expression. When indexing, the input must be numeric, logical, or ':'.

I understand the error is in the index k of Data, but I don't know how to fix it.

Any one can help me?

Thanks

Answer 1

Symbolic variables cannot be used as indices. You need to sum() definite values instead.

sum(abs(Data(1:119,:)-c)-r).^2)

You might need to use bsxfun() to get the right sizes of variables.