need difference equation and for loop help
need difference equation and for loop help
(OP)
I'm attempting to solve a difference equation
y(k+1) = -0.5*y(k) + x(k)
where y(0) = 0 and x(k) is in my case a unit step function ie = 1
well, i'm trying to solve this using a for loop, but am having some trouble. The code i've generated gets an error, "Index into matrix is negative or zero."
Any ideas?
My code is below.
k = 0 ; %counter variable
y = 0; %y(k)
x = 1; %x(k), unit step function
for k = 0 : 5
y(k+1) = -.5*y(k) + x;
y(k) = y(k+1)
end
y(k+1) = -0.5*y(k) + x(k)
where y(0) = 0 and x(k) is in my case a unit step function ie = 1
well, i'm trying to solve this using a for loop, but am having some trouble. The code i've generated gets an error, "Index into matrix is negative or zero."
Any ideas?
My code is below.
k = 0 ; %counter variable
y = 0; %y(k)
x = 1; %x(k), unit step function
for k = 0 : 5
y(k+1) = -.5*y(k) + x;
y(k) = y(k+1)
end





RE: need difference equation and for loop help
If k is zero and you call y(k) what else would you expect?
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: need difference equation and for loop help
xnuke
"Do you think you used enough dynamite there, Butch?"
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.