Function to generate Walsh Code

This function generate Walsh codes, refer to file for more description

This function generates Walsh Codes. The difference between this function and other functions available to generate walsh code is :
1. you can call this function directly in your script, you will have to pass only the value of 'a' (length of code is 2 ^ a)
2. this function can return you both the walsh matrix and randomly selected row (you may need just one sequence for your script)

for usage details refer to file.
syntax: var = walshcode(x)
x = (0, 1, 2, 3, 4, ....)
==> length of code y = 2 .^ x = (1, 2, 4, 8, 16, ....)
by default the var will be a matrix (y x y) for getting any one sequence go to the file and invoke another built in function by removing '%' (refer file)