function y = mysinc(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

endfunction