How to fix "Undefined function 'sinc' for input arguments of type 'double'." Error

I found a code to use for my project far field diffraction generator however, I got an error called, Undefined function 'sinc' for input arguments of type 'double'.

How can i fix this?

Here is my code:

%------------------------------------------------------------------------
%-----Fraunhofer diffraction from a rectangular aperture-----------------
%------------------------------------------------------------------------
clc
close all
clear all
%------------------------------------------------------------------------
lambda=500e-9; k=(2*pi)/lambda; % wavelength of light in vaccuum
a=1e-6; b=1e-6; % dimensions of diffracting rectangular aperture
                % a is along Z and b is along Y
Io=100.0; % relative intensity
R=1.0e-3; % distance of screen from aperture
Y=(-0.25e-2:1e-5:0.25e-2); Z=Y ; % coordinates of screen
beta=k*b*Y/(2*R*pi);alpha=k*a*Z./(2*R*pi); % intermediate variable
 % diffracted intensity
for i=1:length(Y)
    for j=1:length(Z)
I(i,j)=Io.*((sinc(alpha(j)).^2).*(sinc(beta(i))).^2);
    end
end
%------------------------------------------------------------------------
   
 figure(1)
 imshow(I)
 title('Fraunhofer Diffraction','fontsize',14)
 fh = figure(1);
 set(fh, 'color', 'white'); 
 
 %------------------------------------------------------------------------

Answer 1

[KALYAN ACHARJYA]

I didnot find any error, when I run the code in my system (2015b)

clc;
clear all;
close all;
lambda=500e-9; k=(2*pi)/lambda; % wavelength of light in vaccuum
a=1e-6; b=1e-6; % dimensions of diffracting rectangular aperture
                % a is along Z and b is along Y
Io=100.0; % relative intensity
R=1.0e-3; % distance of screen from aperture
Y=(-0.25e-2:1e-5:0.25e-2); Z=Y ; % coordinates of screen
beta=k*b*Y/(2*R*pi);alpha=k*a*Z./(2*R*pi); % intermediate variable
 % diffracted intensity
for i=1:length(Y)
    for j=1:length(Z)
I(i,j)=Io.*((sinc(alpha(j)).^2).*(sinc(beta(i))).^2);
    end
end
%------------------------------------------------------------------------
 figure(1)
 imshow(I)
 title('Fraunhofer Diffraction','fontsize',14)
 fh = figure(1);
 set(fh, 'color', 'white'); 
 
 %------------------------------------------------------------------------
    

[Ege Tunç]

well, when i update matlab and install other tools, issue has been solved. But I don't know why it happened or how it's solved

[Steven Lord]

The sinc function is defined in Signal Processing Toolbox (for numeric arrays) and Symbolic Math Toolbox (for symbolic arrays.) You didn't have Signal Processing Toolbox installed before but now you do.

[Sean]

is this code for near field or far field?