How to write this equation?....want optimized code?

http://latex.codecogs.com/gif.latex?W=\Sigma%20_{k}{\alpha%20_{k}}y_{k}x_{k}

here...alpha is 7x1 matrix(7 elements). 'y' limit is 10x1(10 elements). 'x' limit is 7x50(350 elements).

Answer 1

[Walter Roberson]

The formula you give only makes sense if alpha, y, and x, are all the same length, in which case it would be

sum( alpha .* y .* x )

Otherwise the subscript k makes no sense.

Your arrays are also not the proper size in the proper order in order for matrix multiplication to be intended. (y * alpha transpose * x) could work for matrix multiplication (in which case the multiplication would produce 10 x 50), but then the summation would not make sense. And besides, the order in the equation is not right.