Finish new stats.

src/brmember.scm

@@ -87,6 +87,8 @@
 
   brmember-spec-fee
 
+  brmember-age
+
   brmember-tests!
   )
 
@@ -492,6 +494,18 @@
 	       #f))
 	 #f)))
 
+ (define (brmember-age mr)
+   (let ((born (brmember-info mr 'born #f)))
+     (if born
+	 (let ((lst (string-split born "-")))
+	   (if (null? lst)
+	       #f
+	       (let ((y (string->number (car lst))))
+		 (if y		     
+		     (- (current-year) y)
+		     #f))))
+	 #f)))
+
  ;; Self-tests
  (define (brmember-tests!)
    (run-tests

src/cal-period.scm

@@ -28,6 +28,7 @@
 (module
     cal-period
     (
+     current-year
      *current-month*
      *current-day*
 
@@ -85,6 +86,9 @@
   ;; Type tag
   (define TAG-CAL-PERIOD (make-tag CAL-PERIOD))
 
+  (define (current-year)
+    (cal-month-year (*current-month*)))
+
   ;; Current month - if changed, we get the actual state for given month.
   (define *current-month*
     (make-parameter

src/mbase-query.scm

@@ -47,6 +47,13 @@
   (define (members-base-oldest-month mb)
     (make-cal-month 2015 1))
 
+  (define (members-average-age mrs)
+    (let* ((ages (map brmember-age mrs))
+	   (valid (filter (lambda (x) x) ages))
+	   (num (length valid))
+	   (sum (foldl + 0 valid)))
+      (exact->inexact (/ sum num))))
+
   ;; Returns dictionary with statistics about the members base.
   (define (mbase-info mb-arg)
     (let* ((members (find-members-by-predicate mb-arg brmember-usable?))
@@ -81,10 +88,10 @@
 				   (map (lambda (v)
 					  (min 0 v))
 					mbals))))
-	   ;; debts of fees
+	   (di13 (ldict-set di12 'age
-	   ;; add average age of active members
+			    (members-average-age active-members)))
 	   )
-      di12))
+      di13))
 
   ;; Returns a list two lists: keys, data.
   ;; Each data record contains values for all keys.
@@ -93,6 +100,7 @@
 	   '(month
 	     total active suspended students destroyed invalid
 	     expected balance advance debt
+	     age
 	     )))
       (let mloop ((data '())
 		  (month (members-base-oldest-month mb)))