exercise4():
  Seek parameters for logistic regression example.
  We have N examples of D-dimensional data X.
  For a model
    y(x) = 1 / ( 1 + exp ( - ( w(0) + w(1)*h + w(2)*t ) ) )
  determine the weights w.
  MSE =  0.25

  Computed weights W =  [ 0.21823323 -0.0116291   0.26654793 -0.41607595 -0.19957398  1.27786828]
  New data:
[[ 1 29  2  2  0  1]
 [ 1 33  2  0  2  0]
 [ 1 22  0  1  1  0]]
  Caesarian recommendation?
[1. 1. 0.]

exercise4():
  Normal end of execution.