anchor.diff:        (loop for ar in (read-data "./testdata/ex2data1.txt") collect
              (elt ar 2)))
   
  +(defvar *theta*)
  +(setf *theta* (make-array 3 :initial-element 0))
   
  +(compute-cost *X* *theta* *y*)
  +(partial-derivative-lr *X* *theta* *y*)
  
positive.code:         (rowNum (1- (elt (array-dimensions X) 0))))
      (setf result
            (loop for c from 0 to colNum collect
                  (loop for r from 0 to rowNum for temp = (array-slice X r) sum
                       (* (- (logistic-regression (array-multiply temp theta)) (elt y r))
                          (elt temp c)))))
      result))
  
  (defun gradient-descent-lr (X theta y alpha iterTime)
  
negative.code:       (loop for ind from 0 to (1- (length theta)) do
             (setf (elt theta ind)
                   (- (elt theta ind) (* alpha (elt pd ind)))))
                                          ;(print theta)
        )))
  
  ;;; exercise below
  
  