How can I replace non positive elements of matrix with a certain number

For example A=[7 4 2 1 -0.2 -3]

I want to get [7 4 2 0 0 ]

Answer 1

[Walter Roberson]

max(A,0)

if the replacement is to be 0 for all values less than 0.

Otherwise,

B = A;
B(A<0) = new number

for any other replacement number

[Lily]

thanks