;;; -*- mode: lisp; syntax: common-lisp -*-

(in-package :svm)

(defun test (kernel positive-data negative-data filename

&key (border 5) (scale 10))

"Requires two-dimensional integer data. Outputs a PPM file."

(let* ((decision-fn (svm kernel positive-data negative-data)) ; :iterations 1))

(minx (min (reduce #'min positive-data :key #'first)

(reduce #'min negative-data :key #'first)))

(miny (min (reduce #'min positive-data :key #'second)

(reduce #'min negative-data :key #'second)))

(maxx (max (reduce #'max positive-data :key #'first)

(reduce #'max negative-data :key #'first)))

(maxy (max (reduce #'max positive-data :key #'second)

(reduce #'max negative-data :key #'second)))

(width (* ( (- maxx minx) (* 2 border)) scale))

(height (* ( (- maxy miny) (* 2 border)) scale)))

(with-open-file (s filename :direction :output :if-exists :supersede)

(format s "P3~%~d ~d~%5~%" width height)

(flet ((closep (p q)

(let ((d (v- p q)))

(< (scalar-product d d) 0.5d0))))

(dotimes (y height)

(dotimes (x width)

(let ((pos (list (- ( minx (/ x scale)) border)

(- ( miny (/ y scale)) border))))

(cond ((member pos positive-data :test #'closep)

(format s "0 255 0~%"))

((member pos negative-data :test #'closep)

(format s "255 0 0~%"))

((funcall decision-fn pos)

(format s "255 255 255~%"))

(t (format s "0 0 0~%"))))))))))

;;; Some sample tests

(defparameter *positive-set*

'((8 8) (8 20) (8 44) (8 56) (12 32) (16 16) (16 48)

(24 20) (24 32) (24 44) (28 8) (32 52) (36 16)))

(defparameter *negative-set*

'((36 24) (36 36) (44 8) (44 44) (44 56)

(48 16) (48 28) (56 8) (56 44) (56 52)))

# nil

(test linear-kernel *positive-set* *negative-set* "linear-test.ppm")

# nil

(test (polynomial-kernel 3 nil) *positive-set* *negative-set* "polynomial-test.ppm")

# nil

(test (gaussian-kernel 2.5d0) *positive-set* *negative-set* "gaussian-test.ppm")