n=100; k=10;
  y = randn (1,n);  % generate random vector y
  X = randn (k,n);  % generate random matrix X
  b = y / X
  b = 0.1457109  -0.0777564  -0.0712427  -0.0166193   0.0292955  -0.0079111   0.2265894  -0.0561589  -0.1752146  -0.2577663