The problem is to determine the net worth of the store's inventory. Clearly, we must sum 10,000 numbers where each number is a product of the number of each item and the price of this item. With 10,000 products in the store all this data must be organized in a systematic way. This product is called a row vector times a column vector or dotproduct of two column vectors. Here the net worth is the dotproduct of the inventory vector and the price vector.
T are n dimensional column vectors.
This product has n multiplications and n-1 additions, and we say it has order n operations . Another order n operation is multiplication of a column vector by a constant. Matrix operations which have order n operations are classified as BLAS1 which signifies basic linear algebra subroutine of order n to the first power operations. Most computers have BLAS1 subroutines which have been optimized for the best possible performance on that computer. Application to Investment.