Your T is a vector. You have an expression / another expression. The / operator is not ordinary division: it is matrix division, with A/B being similar to A * pinv(B) where * here indicates algebraic matrix multiplication. The numerator you have only has one column, but the denominator has length(T) columns, but the / operator requires that the number of columns be the same.
It is a lot more likely that you would want to use the ./ operator, which is element-by-element division.