Changeset 30525

Timestamp:

02/26/09 00:19:09 (4 years ago)

Author:

miyamuko

Message:

lang/xyzzy/pci-code: (transform-prefs) p18 2.5 似ている製品

Files:

• lang/xyzzy/pci-code/site-lisp/chapter2/recommendations.l (modified) (1 diff)

lang/xyzzy/pci-code/site-lisp/chapter2/recommendations.l

@@ -172 +172 @@
 ;(get-recommendations *critics* "Toby")
 ;(get-recommendations *critics* "Toby" :similarity #'sim-distance)
+
+
+;;; p18 2.5 似ている製品
+
+(defun transform-prefs (prefs)
+  (labels ((items (prefs person)
+             (mapcar #'car ($ prefs person)))
+           (ratings (prefs person items)
+             (mapcar #'(lambda (item)
+                         ($ prefs person item))
+                     items))
+           (persons (prefs)
+             (mapcar #'car prefs))
+           (all-items (prefs)
+             (remove-duplicates
+              (mapcan #'(lambda (person)
+                          (items prefs person))
+                      (persons prefs))
+              :test #'string=)))
+    (mapcar #'(lambda (item)
+                (cons item
+                      (remove-if-not #'cdr
+                                     (mapcar #'(lambda (person)
+                                                 (cons person ($ prefs person item)))
+                                             (persons prefs)))))
+            (all-items prefs))))
+
+;(transform-prefs *critics*)
+
+;(let ((movies (transform-prefs *critics*)))
+;  (top-matches movies "Superman Returns"))