How to write a function for a nxm matrix

I am trying to write a function that will divide rows by the sum of the column for any size matrix. I have code that works for a 3x3 but am struggling with writing a function to work for any size matrix (for example 500x500).

identity = eye(3);
a2 = xlsread('IO.xlsx', 1, 'B2:D2')
b2 = xlsread('IO.xlsx', 1, 'B3:D3')
c2 = xlsread('IO.xlsx', 1, 'B4:D4')
Xj = xlsread('IO.xlsx', 1, 'B6:D6')
xij = [a2; b2; c2]
format short
A1 = xij(1,:)/Xj(1)
A2 = xij(2,:)/Xj(2)
A3 = xij(3,:)/Xj(3)
A = [A1; A2; A3]
f = randi(200, 3, 1); 
y = [inv(identity - A)]*f

Any guidance would be helpful thanks.

Answer 1

[dpb]

"divide rows by the sum of the column for any size matrix."

x=bsxfun(@rdivide,x,sum(x));

bsxfun takes care of the singleton expansion for you automagically for such cases. The above does the computation in place; assign to a new variable if need to keep the old intact, of course.

[Violet]

Grazie mille!