IIR Filter for loop Code

Can anyone help to code this one using for loop code?

the given filter coefficient

b0 = 0.05

b1 = 0.03

b2 = 0.02

a1 = 0.5

a2 = 0.5

Answer 1

[Mathieu NOE]

hello

if you want to simply plot the bode diagram :

Fs = 1000; % assumed for now ...sampling frequency
b0 = 0.05
b1 = 0.03
b2 = 0.02
a1 = 0.5
a2 = 0.5

numd = [b0 b1 b2];
dend = [1 a1 a2];

dbode(numd,dend,1/Fs);

[Mathieu NOE]

Hi

if my contribution has helped you, do you mind accepting it ?

tx

[Robert Manalo]

Hi sorry for the delay but this one really this means a lot and thank you but im refering to this kind of code:

b0 = 0.05;

b1 = 0.03;

b2 = 0.02;

a1 = 0.5;

a2 = a1;

x = [1 0 0 0 0 0 0 0];

xsize = size(x);

x1 = [0 0 x];

for i=3:xsize(2)

y(i-2) = (b0*x1(i) + b1*x1(i-1) + b2*x1(i-2)) ;

yn = [0 0 y];

end

can you still help continuing....? i dont know if im in the right path

[Mathieu NOE]

ok , so it's about doing a time simulation

you can use filter to do it - you are not obliged to write the recursion yourself (unless it is required)

as it seems you are looking for an impulse response see also dimpulse

b0 = 0.05;
b1 = 0.03;
b2 = 0.02;
a1 = 0.5;
a2 = 0.5;
numd = [b0 b1 b2];
dend = [1 a1 a2];

x = [1 0 0 0 0 0 0 0 0 0 0 0 0 0]; % looks like you're looking for the impulse response ? 
y = filter(numd,dend,x);
figure(1)
plot(y)

% the same impulse response can be obtainde by 
figure(2)
dimpulse(numd,dend);

[Robert Manalo]

thank you mate for this one but what i need is the iir filter using "for loop" code and not about the plotting can you still help me?

[Mathieu NOE]

sure

here you are .

BTW I noticed I made a sign error in the beginning :

dend = [1 -a1 -a2]; % instead of dend = [1 a1 a2];

code updated - see at the end the demo of for loop coding

you can see the 3 methods do show the same result (fortunately !)

clc
clearvars

b0 = 0.05;
b1 = 0.03;
b2 = 0.02;
a1 = 0.5;
a2 = 0.5;
numd = [b0 b1 b2];
dend = [1 -a1 -a2];

x = [1 0 0 0 0 0 0 0 0 0 0 0 0 0]; % looks like you're looking for the impulse response ? 
y = filter(numd,dend,x);

figure(1)
plot(y)

% the same impulse response can be obtainde by 
figure(2)
dimpulse(numd,dend);

% manual for loop coding 
x = [1 0 0 0 0 0 0 0 0 0 0 0 0 0];
samples = length(x);

y(1) = b0*x(1) + 0 + 0  + 0 + 0;
y(2) = b0*x(2) + b1*x(1) + 0  + a1*y(1) + 0;

for k = 3:samples 
    y(k) = b0*x(k) + b1*x(k-1) + b2*x(k-2)  + a1*y(k-1) + a2*y(k-2);
end

figure(3)
plot(y)