Jaccard Coefficients

gistfile1.lisp

(defconstant +main-set-length+ 1000)
(defconstant +subset-length+ 129)
(defconstant +subsets-quantity+ 1000)

(defun create-first-set ()
  (let ((*set* (make-array +main-set-length+ :fill-pointer 0)))
    (dotimes (i +main-set-length+)
      (vector-push (random 1000) *set*))
    (return-from create-first-set *set*)))

(defun get-subset (set)
  (let ((*subset* (make-array +subset-length+ :fill-pointer 0)))
    (dotimes (i +subset-length+)
      (vector-push (elt set (random +main-set-length+)) *subset*))
    (return-from get-subset *subset*)))

(defun get-subsets (set)
  (let ((*subsets* (make-array +subsets-quantity+ :fill-pointer 0)))
    (dotimes (i +subsets-quantity+)
      (vector-push (get-subset set) *subsets*))
    (return-from get-subsets *subsets*)))

(defun sets-intersection (first-set second-set)
  (remove ()
          (map 'vector
               (lambda (item)
                 (find item second-set))
               first-set)))

(defun jaccard-index (first-set second-set)
  (let ((isection (sets-intersection first-set second-set)))
    (/ (length (sets-intersection first-set second-set))
       (+ (length first-set)
          (length second-set)
          (- (length (sets-intersection first-set second-set)))))))


(defvar *sets* (get-subsets (create-first-set)))

(dotimes (i +subsets-quantity+)
  (do ((j i (1+ j)))
    ((>= i +subsets-quantity+))
    (format t
            "~D ~D ~F~%"
            i j
            (jaccard-index (elt *sets* i)
                           (elt *sets* j)))))