(require-extension format)
(require-extension libsvm)
(require-extension srfi-42)

;; read in a sample dataset in svm-light format
(define problem (read-problem "australian_scale.txt"))

(format #t "Problem has ~d instances~&"
       (problem-num-instances problem))

;; create a model from dataset - uses default parameters
(define svm-model (svm-train problem (make-svm-parameter)))

;; display instances with actual and predicted class
(define *correct* 
  (sum-ec (: i (problem-num-instances problem))
          (begin
            (let ((actual (problem-get-label problem i))
                  (predicted (svm-predict svm-model (problem-get-instance problem i))))
              (format #t "Instance ~d: values ~a, class ~2d, predicted ~f ~a~&"
                      (+ 1 i)
                      (problem-get-instance-values (problem-get-instance problem i))
                      actual
                      predicted
                      (if (= actual predicted) 
                        "Y"
                        ""))
              ;; return a '1' for each correct prediction
              (if (= actual predicted) 1 0)))))

;; display summary of performance
(format #t "Proportion correct: ~4,1f%~&" 
        (/ (* 100 *correct*) (problem-num-instances problem)))