anchor.diff:  (defvar *X*)
   (setf *X*
         (let ((temp
  -             (loop for ar in (read-data) collect
  +             (loop for ar in (read-data "./testData.txt") collect
                     (list 1 (elt ar 0)))))
           (make-array (list (length temp) (length (car temp))) :initial-contents temp)))
   
   (defvar *y*)
   (setf *y*
  -      (loop for ar in (read-data) collect
  +      (loop for ar in (read-data "./testData.txt") collect
              (elt ar 1)))
  +
  +(defvar *theta*)
  +(setf *theta* (make-array 2 :initial-element 0))
  +
  +(compute-cost *X* *theta* *y*)
  +(gradient-descent *X* *theta* *y* 0.01 1500)
  
positive.code:          (ar (make-array len :initial-contents ll)))
      ar))
  
  (defun read-data ()
    (let ((result))
      (with-open-file (f #P"./testData.txt"
                         :direction :input)
        (declare (inline *list-to-array))
        (do* ((l (read-line f) (read-line f nil))
  
negative.code:                (1+ rowNum))))
      result))
  
  (defun gradient-descent (X theta y alpha iterTime)
    (dotimes (i iterTime theta)
      (let ((pd (partial-derivative X theta y)))
        (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
  ;;;
  ;;;
  