how to ignore an index error?
4 views (last 30 days)
Show older comments
I have this code and I want to ignore the error when the index exceeds array bounds or when they are 0.
for j=1:N
for i=1:N
u(i,j)=(c(i,j)+u(i-1,j)+u(i+1,j)+u(i,j-1)+u(i,j+1))/4
end
end
I just want to ignore u(0, j), u(N + 1, j), u(i, 0) and u(i, N + 1) or assign them the value 0.
Thank you so much!
1 Comment
dpb
on 14 Dec 2019
Edited: dpb
on 14 Dec 2019
There is no 0-index array element so assigning it any value, zero or not, is out of the question.
You could put the expression in a try...catch...end construct but reconstructing the expression to maintain arrays in bounds would be the better solution.
filter2() possibly would be of use here altho the expression appears somewhat unusual with five terms dividing by four...
Accepted Answer
dpb
on 14 Dec 2019
H=[0 1 0;1 0 1; 0 1 0]; % filter coefficients
u(2:end-1,2:end-1)=(c(2:end-1,2:end-1)+filter2(H,u,'valid'))/4; % apply filtered u to c
0 Comments
More Answers (0)
See Also
Categories
Find more on Matrices and Arrays in Help Center and File Exchange
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!