function [sk,n]=make_sk(wk);
%%%  This function makes the 512-pt sk[n] pulse required by Exercise 6.5 
%%%  in Computer Explorations in Signals & Systems by Buck/Daniel/Singer
%%%
%%%  Function call:  [sk,n]=make_sk(wk)
%%%
%%%  Variables:     
%%%      wk = pulse center frequency (rad/sec)
%%%      sk = pulse vector
%%%       n = vector of time indices

p=[hamming(75); zeros(437,1)];
n=(0:511)';
sk=p.*cos(wk*n);

return