Write a function mymatmin that finds the minimum value in each column of a matrix argument and returns a vector of the column minimums. An example of calling the function follows:

>> mat = randi(20,3,4) mat = 2 20 20 17 6 20 20 3 11 4 10 9

>> mymatmin(mat) ans = 2 4 10 3

However, you cannot use MATLAB's built-in min function to solve the problem. You must use nested-for loop to solve this problem.