Attempted to access delta(-2); index must be a positive integer or logical. Error in ==> ANC at 20 h(n)=delta​(n-3)-2.70​83*delta(n​-4)+4.1861​*delta(n-5​)-3.0451*d​elta(n-6)+​0.73071*de​lta(n-7);

Dear all,

I got this error. please help me. thank you.

Attempted to access delta(-2); index must be a positive integer or logical.

Error in ==> ANC at 20
    h(n)=delta(n-3)-2.7083*delta(n-4)+4.1861*delta(n-5)-3.0451*delta(n-6)+0.73071*delta(n-7);

Answer 1

[Walter Roberson]

When n is 1, n-3 is -2

You loop over n is going to have trouble unless you start at n = 8

What you initialize h(1) through h(7) to is a good question.

By the way, consider conv() with fliplr([0, 0, 1, -2.7083, +4.1861, -3.0451, +0.73071])

[Kuheli Mondal]

Thank you................but if i start n=8 I can't get any point, by the way I send you the full code............can you help me?

clear
close all
N=20;           %order of the filter
mu=0.1;         %step size
fs=100;         %sampling frequency
fn=30;          %noise signal frequency
T=1/fs;
size=4;
A=2; 
n=0:1/fs:size;
w=zeros(N,1);
x=zeros(N,1);
h=zeros(1,N);
y=zeros(N,1);
for n=1:N
x(n)=A*sin(2*pi*fn*1/fs*n);  %noise signal
end
delta(n==0)=1;
for n=1:N
    h(n)=delta(n-3)-2.7083*delta(n-4)+4.1861*delta(n-5)-3.0451*delta(n-6)+0.73071*delta(n-7);
end

[Walter Roberson]

for n=1:N at the end should be replaced with for n=8:N

By the way, after your "for n=1:N", n is going to be left at its last value, N, so in the next line, n==0 is going to be false so no values in delta will be initialized. You do not otherwise initialize delta so your delta is going to be an empty array, which is a problem. You need your delta array to be at least N long.

Your code does not use x after you calculate it.