convolution of 2 discrete signal

hi. this is my code:

clc
clear all
 
n=-2:1:12;
nx = -2:8 ; nh = 0:12; % Set time vectors for x and h
x = usD(n-1) - usD(n-6); % Compute values of x
h = tri((nh-6)/4); % Compute values of h
y = conv(x,h); % Compute the convolution of x with h

ny=(nx(1) + nh(1)) + (0:(length(nx) + length(nh) - 2)) ;

subplot(3,1,1) ; stem(nx,x,'k','filled');
xlabel('n') ; ylabel('x'); axis([-2,20,0,4]);
subplot(3,1,2) ; stem(nh,h,'k','filled') ;
xlabel('n') ; ylabel('h'); axis([-2,20,0,4]);
subplot(3,1,3) ; stem(ny,y,'k','filled');
xlabel('n') ; ylabel('y'); axis([-2,20,0,4]);
 
function z = usD(n)
z = double(n >= 0); % Set output to one for non-
% negative arguments
I = find(round(n) ~= n); % Index non-integer values of n
z(I) = NaN ;
end

function d= tri(n)
....
....
....
end

in this code i want to stem conv(x,h). i need to define function tri in the last. can u help me.

the result:

[KALYAN ACHARJYA]

Please do share tri function file. Is the x and h having same length?

Answer 1

[Pramil]

Hi Hadimargo,

Based on your code, and result image, it looks like you want to create a triangular waveform. Here’s how you can define the "tri" function:

function d = tri(n)

% Create triangular waveform centered at zero

d = max(1 - abs(n), 0);

end

This function will generate a triangular waveform with a peak value of 1 and a base width of 2 units. You can adjust the function as needed to fit your specific requirements.

Here’s your complete code with the "tri" function defined:

clc
clear all

n = -2:1:12;
nx = -2:12; nh = 0:14; % Set time vectors for x and h
x = usD(n-1) - usD(n-6); % Compute values of x
h = tri((nh-6)/4); % Compute values of h
y = conv(x,h); % Compute the convolution of x with h
ny = (nx(1) + nh(1)) + (0:(length(nx) + length(nh) - 2));
subplot(3,1,1); stem(nx,x,'k','filled');
xlabel('n'); ylabel('x'); axis([-2,20,0,4]);
subplot(3,1,2); stem(nh,h,'k','filled');
xlabel('n'); ylabel('h'); axis([-2,20,0,4]);
subplot(3,1,3); stem(ny,y,'k','filled');
xlabel('n'); ylabel('y'); axis([-2,20,0,4]);

function z = usD(n)
    z = double(n >= 0); % Set output to one for non-negative arguments
    I = find(round(n) ~= n); % Index non-integer values of n
    z(I) = NaN;
end

function d = tri(n)
    % Create triangular waveform centered at zero
    d = max(1 - abs(n), 0);
end 

This should give you the desired convolution plot.