The N-Point Moving Average (MA) Filter

- Write a Matlab code to load the input signal x[n],

clc
clear all
close all

N = input('Enter Order of Filter: ');
n = 0:N-1;

for k=n
y(k)=(1/N)*(sum(x(k:-1:k-N+1)))
end

plot(y(n))

I have such a solution for step 1, but I get an error. 'Unrecognized function or variable' x '.'

clc
clear all
close all

N = input('Enter Order of Filter: ');
n = 0:N-1;
x = 5;
for k=n
y(k)=(1/N)*(sum(x(k:-1:k-N+1)))
end

plot(y(n))

I get this error when I enter any value for X. 'Array indices must be positive integers or logical values.' How can I fix this problem?

- Then the reduce the noise of this signal using the given MA filter.

I do not know how to reduce the noise, I could not find a useful resource.

- Finally plot the original signal and the filtered one in the same figure.

Answer 1

[vidyesh]

Hello,

I see that you're working on implementing an N-point moving average filter in MATLAB and are encountering a couple of issues. Let's address these errors step by step:

The error 'Unrecognized function or variable x' is due to x not being defined before it's used in the loop. In MATLAB, you need to define all the variables before you can use them. Ensure that x is an existing array with your input signal data before the loop starts.

Regarding the error stating 'Array indices must be positive integers or logical values', note that MATLAB indexing begins at 1. When assigning values to y(k), it is crucial to ensure that the indices used to access elements of x fall within the permissible range. This means indices should be greater than or equal to 1 and less than or equal to the length of the array x. Any attempt to access x using an index outside this range will result in an error.

For more information on arrays, refer the below documentation page:

https://www.mathworks.com/help/matlab/math/array-indexing.html

Hope this helps.