How to ignore negative indices or assign it to zero in a loop

6 views (last 30 days)
x=[1 2 -1 -3 -4]
h=[0 1 3]
n=length(x)
m=length(h)
y=zeros(n,m)
for i=1:n
for j=1:m
if i-j>0
y(i,j)=h(j)*x(i-j+1)
else
y(i,j)=0 % My problem is here to assign if the element x(i-j) does not exist return zero
%but it is ignoring all the element in the matrix that is (i-j)< zero
end
end
end
I have tried approach this problem by setting up a matrix, however i did not start loop from zero since it is same both way if i am right

Accepted Answer

Stephan
Stephan on 5 May 2021
Edited: Stephan on 5 May 2021
It is not needed to make the elements zero - they are already, because you preallocated y with zeros:
x=[1 2 -1 -3 -4]
h=[0 1 3]
n=length(x)
m=length(h)
y=zeros(n,m)
for i=1:n
for j=1:m
if i-j>0
y(i,j)=h(j)*x(i-j+1)
end
end
end
gives:
% alot of stuff
% ...
y =
0 0 0
0 0 0
0 2 0
0 -1 6
0 -3 -3
  3 Comments

Sign in to comment.

More Answers (0)

Categories

Find more on Programming in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!