Set zero in certain rows of an array to value x

Hi,

I have an 3x6 array A:

A=[1 1 0 1 0 1;1 1 0 0 1 1; 1 1 0 1 1 1];

x=1000000;

Now i want to set all zeros in row 2 and 3 to 1.000.000. The zeros in row 1 shall stay zero, so

A(A==0)=x;

doesn`t work, because it makes every zero in the whole array to value 1000000.

I tried it with help of an if-condition, but it doesn´t work either:

if A(2:3,:)==0

A(2:3,:)=x;

end

I will greatly appreciate any assistance.

Answer 1

[Jan]

A = [1 1 0 1 0 1;1 1 0 0 1 1; 1 1 0 1 1 1];
x = 1000000;

% all zeros in row 2 and 3 to 1.000.000
match       = (A == 0);
match(1, :) = false;  % Do not access 1st row
A(match)    = x

or

B         = A(2:3, :);
B(B == 0) = x;
A(2:3, :) = B

[Max Bornemann]

Thank you! I´m really impressed of how fast I receive answers here, genious!

Answer 2

[Andrei Bobrov]

A((A + [0;2;2]) == 2) = 1e6;

[Max Bornemann]

Thank you!