problem with function sinc

hello everyone

i have a problem with the function sinc (i'm not so expert i started to use mathlab 3 months ago) and i wrote this:

x = 0:pi/100:2*pi;

y=sinc(x);

but i have an error:

Undefined function 'sinc' for input arguments of type 'double'.

someone can help me? thanks

Answer 1

[Birdman]

Adapt its formula as follows:

x = 0:pi/100:2*pi;
y=sin(pi*x)./(pi*x);%sinc function
plot(y)

[Jack]

It's also perhaps worth stating that some people (e.g. physicists) define as opposed to (which is more commonly used in the signal processing community).

[Birdman]

The OP can adapt the formula according to the need I guess. My aim was to give the idea on implementation.

[dert sgt]

thanks to everyone so it's imposible to use sinc(x)? because it's easier for example or something similar

[dert sgt]

yes jack someone uses

[Birdman]

Actually you should be able to use sinc(x) function but I guess you do not have signal processing toolbox or symbolic math toolbox which is required to use sinc(x). So, we have implemented the function according to its formula.

x = 0:pi/100:2*pi;
y=sin(pi*x)./(pi*x);%sinc function
plot(y)

or

x = 0:pi/100:2*pi;
y=sin(x)./x;%sinc function
plot(y)

[Jack]

While the singal processing toolbox has sinc() defined explicitly, you can always create a function that does this -- e.g. put the following in a file called sinc.m somewhere in your current path (or in ~/Documents/MATLAB/ or My Documents\MATLAB\)

function out = sinc(x)
% Deal with the removable singularity at 0 explicitly.
out = sin(x)./x;
out(x == 0) = 1;
end

[dert sgt]

thanks so much again you're fantastic!