1 files changed, 55 insertions, 0 deletions
diff --git a/bench.scm b/bench.scm
new file mode 100644
index 0000000..acb4a2c
--- /dev/null
+++ b/bench.scm
@@ -0,0 +1,55 @@
+
+(require (in-vicinity (implementation-vicinity) "pi.scm"))
+(require 'transcript)
+(define isqrt
+  (cond ((provided? 'inexact) sqrt)
+	(else (require 'root) integer-sqrt)))
+(define i/
+  (cond ((provided? 'inexact) /)
+	(else quotient)))
+(define around
+  (cond ((provided? 'inexact)
+	 (lambda (x)
+	   (cond ((>= 3000 (abs x) 3) (inexact->exact (round x)))
+		 (else x))))
+	(else identity)))
+
+(define (time-pi digits)
+  (let ((start-time (get-internal-run-time)))
+    (pi digits 4)
+    (i/ (* 1000 (- (get-internal-run-time) start-time))
+       internal-time-units-per-second)))
+
+(define (benchmark . arg)
+  (define file
+    (cond ((null? arg) "bench.log")
+	  (else (car arg))))
+  (do ((digits 50 (+ digits digits))
+       (t 0 (time-pi (+ digits digits))))
+      ((> t 3000)
+       (do ((tl '() (cons (time-pi digits) tl))
+	    (j 12 (+ -1 j)))
+	   ((zero? j)
+	    (let* ((avg (i/ (apply + tl) (length tl)))
+		   (dev (isqrt (i/ (apply
+				    + (map (lambda (x) (* (- x avg) (- x avg)))
+						 tl))
+				   (length tl)))))
+	      (and file (transcript-on file))
+	      (for-each display
+			(list digits " digits took " (around avg) " mSec +/- "
+			      (around dev) " mSec."))
+	      (newline)
+	      (let ((scaled-avg (i/ (* (i/ (* avg 1000) digits) 1000) digits)))
+		(for-each display
+			  (list " That is about " scaled-avg
+				" mSec/k-digit^2 +/- "
+				(around
+				 (i/ (* 100 (i/ (* (i/ (* dev 1000) digits)
+						   1000) digits))
+				     scaled-avg))
+				"%."))
+		(newline)
+		(and file (transcript-off)))
+	      ))))))
+(benchmark)