function y = sinc(x)
% this function calculates the "sinc" of its argument,
% defined as
%                     sin(x)
%         sinc(x)  = ---------
%                       x
%                       
% Input arguments:      
%         x           a floating-point value; we treat it has
%                          having units of radians when taking sine
%                          
% we check to make sure that the argument is not zero before
% we perform the calculation; if it is, then we return 1, which
% is the proper limit as the argument approaches 0

   if (x == 0) 
     y = 1;
   else
     y = sin(x) / x;
   end


