anchor.diff:        (loop for ind from 0 to (1- (length theta)) do
              (setf (elt theta ind)
                    (- (elt theta ind) (* alpha (elt pd ind)))))
  -      (print theta))))
  +                                        ;(print theta)
  +      )))
   
   ;;; exercise below
   
  
positive.code:       (loop for ar in (read-data "./testdata/ex2data1.txt") collect
             (elt ar 2)))
  
  
  
negative.code:     (setf result
            (loop for r from 0 to rowNum for temp = (array-slice X r) sum
                 (if (= (nth r y) 1)
                     (- (log (logistic-regression (array-multiply temp theta))))
                     (- (log (- 1 (logistic-regression (array-multiply temp theta))))))))
      (/ result rowNum)))
  
  (defun partial-derivative-lr (X theta y)
  