From: sheepman <sheepman@...>
Date: 2005-01-04T11:19:50+09:00
Subject: [ruby-dev:25399] Re: rand uniformity

こんにちは、sheepman です。

符合を忘れていました。

Index: bignum.c
===================================================================
RCS file: /src/ruby/bignum.c,v
retrieving revision 1.109
diff -u -r1.109 bignum.c
--- bignum.c	3 Sep 2004 09:00:51 -0000	1.109
+++ bignum.c	4 Jan 2005 02:15:29 -0000
@@ -2015,11 +2015,14 @@
 	return rb_float_new(rand_buf[0]);
     }
     v = bignew(len,1);
+    RBIGNUM(v)->sign = RBIGNUM(max)->sign;
+    len--;
+    BDIGITS(v)[len] = BDIGITS(max)[len] * rand_buf[len];    
     while (len--) {
 	BDIGITS(v)[len] = ((BDIGIT)~0) * rand_buf[len];
     }
 
-    return rb_big_modulo((VALUE)v, max);
+    return v;
 }
 
 /*

-- 
sheepman / TAMURA Takashi
sheepman@tcn.zaq.ne.jp http://sheepman.parfait.ne.jp/