* guile: some internal improvements

guile/examples/msg-graphs

@@ -29,7 +29,7 @@ Sun..Sat) that match EXPR. If PLAIN-TEXT is true, use a plain-text
 display, otherwise, use a graphical window."
   (mu:plot
     (sort
-      (mu:tabulate-messages
+      (mu:tabulate
 	(lambda (msg)
 	  (tm:hour (localtime (mu:date msg)))) expr)
       (lambda (x y) (< (car x) (car y))))
@@ -41,7 +41,7 @@ Sun..Sat) that match EXPR. If PLAIN-TEXT is true, use a plain-text
 display, otherwise, use a graphical window."
   (mu:plot
     (mu:weekday-numbers->names
-      (sort (mu:tabulate-messages
+      (sort (mu:tabulate
 	      (lambda (msg)
 		(tm:wday (localtime (mu:date msg)))) expr)
 	(lambda (x y) (< (car x) (car y)))))
@@ -54,7 +54,7 @@ display, otherwise, use a graphical window."
   (mu:plot
     (mu:month-numbers->names
       (sort
-	(mu:tabulate-messages
+	(mu:tabulate
 	  (lambda (msg)
 	    (tm:mon (localtime (mu:date msg)))) expr)
 	(lambda (x y) (< (car x) (car y)))))
@@ -66,10 +66,10 @@ display, otherwise, use a graphical window."
 Sun..Sat) that match EXPR. If PLAIN-TEXT is true, use a plain-text
 display, otherwise, use a graphical window."
   (mu:plot
-    (sort (mu:tabulate-messages
+    (sort (mu:tabulate
 	    (lambda (msg)
 	      (string->number
-		(format #f "~d~2'0d"	
+		(format #f "~d~2'0d"
 		  (+ 1900 (tm:year (localtime (mu:date msg))))
 		  (tm:mon (localtime (mu:date msg))))))
 	    expr)
@@ -84,7 +84,7 @@ display, otherwise, use a graphical window."
 Sun..Sat) that match EXPR. If PLAIN-TEXT is true, use a plain-text
 display, otherwise, use a graphical window."
   (mu:plot
-    (sort (mu:tabulate-messages
+    (sort (mu:tabulate
 	    (lambda (msg)
 	      (+ 1900 (tm:year (localtime (mu:date msg))))) expr)
       (lambda (x y) (< (car x) (car y))))
@@ -118,7 +118,7 @@ display, otherwise, use a graphical window."
       ((string= what "per-hour")  (per-hour expr text))
       ((string= what "per-day")   (per-day expr text))
       ((string= what "per-month") (per-month expr text))
-      ((string= what "per-year-month") (per-year-month expr text)) 
+      ((string= what "per-year-month") (per-year-month expr text))
       ((string= what "per-year")  (per-year expr text))
       (else (begin
 	      (display msg)

guile/mu-guile.texi

@@ -1,4 +1,4 @@
-\input texinfo.tex    @c -*-texinfo-*-
+\\input texinfo.tex    @c -*-texinfo-*-
 @c %**start of header
 @setfilename mu-guile.info
 @settitle mu-guile user manual
@@ -663,7 +663,7 @@ probably be a bit more elegant.
 @t{mu-guile} offers some convenience functions to determine various statistics
 about the messages in the database.
 
-@code{(mu:tabulate-messages <function> [<search-expr>])} applies
+@code{(mu:tabulate <function> [<search-expr>])} applies
 @t{<function>} to each message matching @t{<search-expr>} (leave empty to
 match @emph{all} messages), and returns a associative list (a list of pairs)
 with each of the different results of @t{<function>} and their frequencies.
@@ -683,7 +683,7 @@ exec guile -s $0 $@
 (define weekday-table
   (mu:weekday-numbers->names
     (sort
-      (mu:tabulate-messages
+      (mu:tabulate
 	(lambda (msg)
 	  (tm:wday (localtime (mu:date msg)))))
       (lambda (a b) (< (car a) (car b))))))
@@ -751,7 +751,7 @@ exec guile -s $0 $@
 
 (define (mail-per-hour-table)
   (sort
-    (mu:tabulate-messages
+    (mu:tabulate
       (lambda (msg)
 	(tm:hour (localtime (mu:date msg)))))
     (lambda (x y) (< (car x) (car y)))))

guile/mu/stats.scm

@@ -21,17 +21,22 @@
   :use-module (mu message)
   :use-module (srfi srfi-1)
   :use-module (ice-9 i18n)
-  :export ( mu:tabulate-messages
-	    mu:average-messages
+  :use-module (ice-9 r5rs)
+  :export ( mu:tabulate
+	    mu:average
+	    mu:stddev
 	    mu:weekday-numbers->names
 	    mu:month-numbers->names))
 
-(define* (mu:tabulate-messages func #:optional (expr #t))
+
+(define* (mu:tabulate func #:optional (expr #t))
   "Execute FUNC for each message matching EXPR, and return an alist
 with maps each result of FUNC to its frequency. FUNC is a function
 takes a <mu-message> instance as its argument. For example, to
 tabulate messages by weekday, one could use:
-   (mu:tabulate-messages (lambda(msg) (tm:wday (localtime (date msg)))))."
+   (mu:tabulate (lambda(msg) (tm:wday (localtime (date msg))))), and
+get back a list like
+   ((1 . 2) (2 . 5)(3 . 4)(4 . 4)(5 . 12)(6 . 7)(7. 2))."
   (let ((table '()))
     (mu:for-each-message
       (lambda(msg)
@@ -41,34 +46,52 @@ tabulate messages by weekday, one could use:
       expr)
     table))
 
+(define (average lst)
+  "Calculate the average of a list LST of numbers, or #f if undefined."
+  (if (null? lst)
+    #f
+    (/ (apply + lst) (length lst))))
+
+(define (stddev lst)
+  "Calculate the standard deviation of a list LST of numbers or #f if
+undefined."
+  (let* ((avg (average lst))
+	  (sosq (if avg
+		  (apply + (map (lambda (x)(* (- x avg) (- x avg))) lst)))))
+    (if sosq
+      (sqrt (/ sosq (length lst))))))
+
+
+(define* (mu:average func #:optional (expr #t))
+  "Get the average value of FUNC applied to all messages matching
+EXPR (or #t for all). Returns #f if undefined."
+  (average (map func (mu:message-list expr))))
+
+(define* (mu:stddev func #:optional (expr #t))
+  "Get the standard deviation for the the values of FUNC applied to
+all messages matching EXPR (or #t for all). Returns #f if undefined."
+  (stddev (map func (mu:message-list expr))))
+
+
+(define* (mu:max func #:optional (expr #t))
+  "Get the maximum value of FUNC applied to all messages matching
+EXPR (or #t for all). Returns #f if undefined."
+  (apply max (map func (mu:message-list expr))))
+
+(define* (mu:min func #:optional (expr #t))
+  "Get the minimum value of FUNC applied to all messages matching
+EXPR (or #t for all). Returns #f if undefined."
+  (apply min (map func (mu:message-list expr))))
 
-(define* (mu:average-messages func #:optional (expr #t))
-  "Execute FUNC for each message matching EXPR, and return the average
-value of the results of FUNC.  FUNC is a function that takes a
-<mu-message> instance as its argument, and returns some number. For
-example, to get the average message size of messages related to
-icecream:  (mu:average (lambda(msg) (size msg)) \"icecream\" ."
-(let ((count 0) (sum 0))
-  (mu:for-each-message
-    (lambda (msg)
-      (set! count (+1 count))
-      (set! sum (+ sum (func msg))))
-    expr)
-  (if (= count 0)
-    0
-    (exact->inexact (/ sum count)))))
 
 ;; a list of abbreviated, localized day names
 (define day-names
-  (map
-    (lambda (num)
-      (locale-day-short num))
-      (iota 7 1)))
+  (map locale-day-short (iota 7 1)))
 
 (define (mu:weekday-numbers->names table)
   "Convert a list of pairs with the car denoting a day number (0-6)
 into a list of pairs with the car replaced by the corresponding day
-name (abbreviated)."
+name (abbreviated) for the current locale."
     (map
       (lambda (pair)
 	(cons (list-ref day-names (car pair)) (cdr pair)))
@@ -76,10 +99,7 @@ name (abbreviated)."
 
 ;; a list of abbreviated, localized month names
 (define month-names
-  (map
-    (lambda (num)
-      (locale-month-short num))
-      (iota 12 1)))
+  (map locale-month-short (iota 12 1)))
 
 (define (mu:month-numbers->names table)
     "Convert a list of pairs with the car denoting a month number (0-11)