More pathes from Tadasi Saito.

As discussed in ruby-dev ML:
  E,PI, etc are disabled.
  BigDecimal op String disabled.
  to_f changed.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@4091 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

5 files changed, 263 insertions, 174 deletions

diff --git a/ext/bigdecimal/MANIFEST b/ext/bigdecimal/MANIFEST
index 7408e05284..8e9415eeea 100644
--- a/ext/bigdecimal/MANIFEST
+++ b/ext/bigdecimal/MANIFEST
@@ -7,10 +7,10 @@ depend
 extconf.rb
 bigdecimal_en.html
 bigdecimal_ja.html
-lib/jacobian.rb
-lib/newton.rb
-lib/ludcmp.rb
-lib/bigdecimal-rational.rb
+lib/bigdecimal/jacobian.rb
+lib/bigdecimal/newton.rb
+lib/bigdecimal/ludcmp.rb
+lib/bigdecimal/util.rb
 sample/linear.rb
 sample/nlsolve.rb
 sample/pi.rb
diff --git a/ext/bigdecimal/bigdecimal.c b/ext/bigdecimal/bigdecimal.c
index 4a04d2a94a..8f86108e4f 100644
--- a/ext/bigdecimal/bigdecimal.c
+++ b/ext/bigdecimal/bigdecimal.c
@@ -9,6 +9,7 @@
  * of this BigDecimal distribution.
  *
  * NOTES:
+ *  For the notes other than listed bellow,see ruby CVS log.
  *  2003-04-17
  *    Bug in negative.exp(n) reported by Hitoshi Miyazaki fixed.
  *  2003-03-28
@@ -34,11 +35,16 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <errno.h>
+#include <float.h>
+#include <math.h>
 #include "ruby.h"
 #include "math.h"
 #include "version.h"
-
-/* #define USE_MUTABLE_METHOD */
+ 
+/* #define ENABLE_NUMERIC_STRING */
+/* #define ENABLE_TRIAL_METHOD   */
+/* #define ENABLE_BANG_METHOD    */
 
 VALUE rb_cBigDecimal;
 
@@ -96,7 +102,6 @@ do_coerce(VALUE *x, VALUE *y)
 {
     VALUE ary;
     VALUE a[2];
-
     a[0] = *x; a[1] = *y;
     ary = rb_rescue(coerce_body, (VALUE)a, coerce_rescue, (VALUE)a);
     if (TYPE(ary) != T_ARRAY || RARRAY(ary)->len != 2) {
@@ -135,7 +140,6 @@ ToValue(Real *p)
 static Real *
 GetVpValue(VALUE v, int must)
 {
-    double dv;
     Real *pv;
     VALUE bg;
     char szD[128];
@@ -153,40 +157,14 @@ GetVpValue(VALUE v, int must)
     case T_FIXNUM:
         sprintf(szD, "%d", FIX2INT(v));
         return VpCreateRbObject(VpBaseFig() * 2 + 1, szD);
-    case T_FLOAT:
-        pv = VpCreateRbObject(VpDblFig()*2,"0");
-        dv = RFLOAT(v)->value;
-        /* From float */
-        if (isinf(dv)) {
-            VpException(VP_EXCEPTION_INFINITY,"Computation including infinity",0);
-            if(dv==VpGetDoublePosInf()) {
-                VpSetPosInf(pv);
-            } else {
-                VpSetNegInf(pv);
-            }
-        } else
-        if (isnan(dv)) {
-            VpException(VP_EXCEPTION_NaN,"Computation including NaN(Not a number)",0);
-            VpSetNaN(pv);
-        } else {
-            if (VpIsNegDoubleZero(dv)) {
-                VpSetNegZero(pv);
-            } else if(dv==0.0) {
-                VpSetPosZero(pv);
-            } else if(dv==1.0) {
-                VpSetOne(pv);
-            } else if(dv==-1.0) {
-                VpSetOne(pv);
-                pv->sign = -pv->sign;
-            } else {
-                VpDtoV(pv,dv);
-            }
-        }
-        return pv;
+
+#ifdef ENABLE_NUMERIC_STRING
     case T_STRING:
         SafeStringValue(v);
         return VpCreateRbObject(strlen(RSTRING(v)->ptr) + VpBaseFig() + 1,
                                 RSTRING(v)->ptr);
+#endif /* ENABLE_NUMERIC_STRING */
+
     case T_BIGNUM:
         bg = rb_big2str(v, 10);
         return VpCreateRbObject(strlen(RSTRING(bg)->ptr) + VpBaseFig() + 1,
@@ -449,15 +427,43 @@ BigDecimal_induced_from(VALUE self, VALUE x)
 }
 
 static VALUE
+BigDecimal_to_f(VALUE self)
+{
+    ENTER(1);
+    Real *p;
+    double d, d2, da;
+    S_LONG e;
+
+    GUARD_OBJ(p,GetVpValue(self,1));
+    if(VpVtoD(&d, &e, p)!=1) return rb_float_new(d);
+    errno = 0;
+    d2 = pow(10.0,(double)e);
+    da = fabs(d);
+    if(errno == ERANGE  || da > (DBL_MAX / d2) || da < (DBL_MIN / d2)) {
+        U_LONG nc = VpNumOfChars(p)+1;
+        char *psz = ALLOCA_N(char, nc);
+        VpToString(p, psz, 0);
+        rb_raise(rb_eRangeError, "BigDecimal %s out of Float range", psz);
+    }
+    return rb_float_new(d*d2);
+}
+
+static VALUE
 BigDecimal_coerce(VALUE self, VALUE other)
 {
     ENTER(2);
     VALUE obj;
     Real *b;
-    GUARD_OBJ(b,GetVpValue(other,1));
-    obj = rb_ary_new();
-    obj = rb_ary_push(obj, b->obj);
-    obj = rb_ary_push(obj, self);
+    if(TYPE(other) == T_FLOAT) {
+       obj = rb_ary_new();
+       obj = rb_ary_push(obj,other);
+       obj = rb_ary_push(obj,BigDecimal_to_f(self));
+    } else {
+       GUARD_OBJ(b,GetVpValue(other,1));
+       obj = rb_ary_new();
+       obj = rb_ary_push(obj, b->obj);
+       obj = rb_ary_push(obj, self);
+    }
     return obj;
 }
 
@@ -677,14 +683,14 @@ BigDecimal_div(VALUE self, VALUE r)
     ENTER(5);
     Real *c=NULL, *res=NULL, *div = NULL;
     r = BigDecimal_divide(&c, &res, &div, self, r);
-    SAVE(c);SAVE(res);SAVE(div);
     if(r!=(VALUE)0) return r; /* coerced by other */
+    SAVE(c);SAVE(res);SAVE(div);
     /* a/b = c + r/b */
     /* c xxxxx
        r 00000yyyyy  ==> (y/b)*BASE >= HALF_BASE
      */
     /* Round */
-    if(VpIsDef(c)) {
+    if(VpIsDef(c) && (!VpIsZero(c))) {
        VpInternalRound(c,0,c->frac[c->Prec-1],(VpBaseVal()*res->frac[0])/div->frac[0]);
     }
     return ToValue(c);
@@ -731,8 +737,8 @@ BigDecimal_mod(VALUE self, VALUE r) /* %: a%b = a - (a.to_f/b).floor * b */
     Real *div=NULL, *mod=NULL;
 
     obj = BigDecimal_DoDivmod(self,r,&div,&mod);
-    SAVE(div);SAVE(mod);
     if(obj!=(VALUE)0) return obj;
+    SAVE(div);SAVE(mod);
     return ToValue(mod);
 }
 
@@ -867,19 +873,6 @@ BigDecimal_mult2(VALUE self, VALUE b, VALUE n)
 }
 
 static VALUE
-BigDecimal_dup(VALUE self)
-{
-    ENTER(5);
-    Real *c, *a;
-    U_LONG mx;
-    GUARD_OBJ(a,GetVpValue(self,1));
-    mx = a->Prec *(VpBaseFig() + 1);
-    GUARD_OBJ(c,VpCreateRbObject(mx, "0"));
-    VpAsgn(c, a, 1);
-    return ToValue(c);
-}
-
-static VALUE
 BigDecimal_abs(VALUE self)
 {
     ENTER(5);
@@ -967,7 +960,6 @@ BigDecimal_truncate(int argc, VALUE *argv, VALUE self)
     ENTER(5);
     Real *c, *a;
     int iLoc;
-    int sw;
     U_LONG mx;
     VALUE vLoc;
 
@@ -1081,9 +1073,7 @@ BigDecimal_split(VALUE self)
     VpSzMantissa(vp,psz1);
     s = 1;
     if(psz1[0]=='-') {
-        int i=0;
-        s = -1;
-        while(psz1[i]=psz1[i+1]) i++ ;
+        s = -1; ++psz1;
     }
     if(psz1[0]=='N') s=0; /* NaN */
     e = VpExponent10(vp);
@@ -1151,6 +1141,25 @@ BigDecimal_power(VALUE self, VALUE p)
 }
 
 static VALUE
+BigDecimal_global_new(int argc, VALUE *argv, VALUE self)
+{
+    ENTER(5);
+    Real *pv;
+    S_LONG mf;
+    VALUE  nFig;
+    VALUE  iniValue;
+
+    if(rb_scan_args(argc,argv,"11",&iniValue,&nFig)==1) {
+        mf = 0;
+    } else {
+        mf = GetPositiveInt(nFig);
+    }
+    SafeStringValue(iniValue);
+    GUARD_OBJ(pv,VpCreateRbObject(mf, RSTRING(iniValue)->ptr));
+    return ToValue(pv);
+}
+
+static VALUE
 BigDecimal_new(int argc, VALUE *argv, VALUE self)
 {
     ENTER(5);
@@ -1183,6 +1192,14 @@ BigDecimal_limit(int argc, VALUE *argv, VALUE self)
 }
 
 static VALUE
+BigDecimal_sign(VALUE self)
+{ /* sign */
+    int s = GetVpValue(self,1)->sign;
+    return INT2FIX(s);
+}
+
+#ifdef ENABLE_TRIAL_METHOD
+static VALUE
 BigDecimal_e(VALUE self, VALUE nFig)
 {
     ENTER(5);
@@ -1223,13 +1240,6 @@ BigDecimal_exp(VALUE self, VALUE nFig)
 }
 
 static VALUE
-BigDecimal_sign(VALUE self)
-{ /* sign */
-    int s = GetVpValue(self,1)->sign;
-    return INT2FIX(s);
-}
-
-static VALUE
 BigDecimal_sincos(VALUE self, VALUE nFig)
 {
     ENTER(5);
@@ -1252,9 +1262,9 @@ BigDecimal_sincos(VALUE self, VALUE nFig)
     rb_ary_push(obj, objCos);
     return obj;
 }
+#endif /* ENABLE_TRIAL_METHOD */
 
-
-#ifdef USE_MUTABLE_METHOD
+#ifdef ENABLE_BANG_METHOD
 /**** Following methods are all MUTABLE and not currently activated. ****/
 static void
 CheckAssign(VALUE x, VALUE y)
@@ -1348,7 +1358,7 @@ BigDecimal_mult3(VALUE self, VALUE c, VALUE a, VALUE b)
     f = VpMult(cv,av,bv);
     return INT2NUM(f);
 }
-#endif /* USE_MUTABLE_METHOD */
+#endif /* ENABLE_BANG_METHOD */
 
 void
 Init_bigdecimal(void)
@@ -1359,13 +1369,14 @@ Init_bigdecimal(void)
     /* Class and method registration */
     rb_cBigDecimal = rb_define_class("BigDecimal",rb_cNumeric);
 
+    /* Global function */
+    rb_define_global_function("BigDecimal", BigDecimal_global_new, -1);
+
     /* Class methods */
     rb_define_singleton_method(rb_cBigDecimal, "mode", BigDecimal_mode, 2);
     rb_define_singleton_method(rb_cBigDecimal, "new", BigDecimal_new, -1);
     rb_define_singleton_method(rb_cBigDecimal, "limit", BigDecimal_limit, -1);
-    rb_define_singleton_method(rb_cBigDecimal, "E", BigDecimal_e, 1);
     rb_define_singleton_method(rb_cBigDecimal, "double_fig", BigDecimal_double_fig, 0);
-    rb_define_singleton_method(rb_cBigDecimal, "PI", BigDecimal_pi, 1);
     rb_define_singleton_method(rb_cBigDecimal, "induced_from",BigDecimal_induced_from, 1);
     rb_define_singleton_method(rb_cBigDecimal, "_load", BigDecimal_load, 1);
 
@@ -1417,8 +1428,8 @@ Init_bigdecimal(void)
     rb_define_method(rb_cBigDecimal, "modulo", BigDecimal_mod, 1);
     rb_define_method(rb_cBigDecimal, "remainder", BigDecimal_remainder, 1);
     rb_define_method(rb_cBigDecimal, "divmod", BigDecimal_divmod, 1);
-    rb_define_method(rb_cBigDecimal, "dup", BigDecimal_dup, 0);
-    rb_define_method(rb_cBigDecimal, "to_f", BigDecimal_dup, 0); /* to_f === dup */
+    /* rb_define_method(rb_cBigDecimal, "dup", BigDecimal_dup, 0); */
+    rb_define_method(rb_cBigDecimal, "to_f", BigDecimal_to_f, 0);
     rb_define_method(rb_cBigDecimal, "abs", BigDecimal_abs, 0);
     rb_define_method(rb_cBigDecimal, "sqrt", BigDecimal_sqrt, 1);
     rb_define_method(rb_cBigDecimal, "fix", BigDecimal_fix, 0);
@@ -1428,8 +1439,6 @@ Init_bigdecimal(void)
     rb_define_method(rb_cBigDecimal, "ceil", BigDecimal_ceil, -1);
     rb_define_method(rb_cBigDecimal, "power", BigDecimal_power, 1);
     rb_define_method(rb_cBigDecimal, "**", BigDecimal_power, 1);
-    rb_define_method(rb_cBigDecimal, "exp", BigDecimal_exp, 1);
-    rb_define_method(rb_cBigDecimal, "sincos", BigDecimal_sincos, 1);
     rb_define_method(rb_cBigDecimal, "<=>", BigDecimal_comp, 1);
     rb_define_method(rb_cBigDecimal, "==", BigDecimal_eq, 1);
     rb_define_method(rb_cBigDecimal, "===", BigDecimal_eq, 1);
@@ -1451,20 +1460,27 @@ Init_bigdecimal(void)
     rb_define_method(rb_cBigDecimal, "truncate",  BigDecimal_truncate, -1);
     rb_define_method(rb_cBigDecimal, "_dump", BigDecimal_dump, -1);
 
-#ifdef USE_MUTABLE_METHOD
+#ifdef ENABLE_TRIAL_METHOD
+    rb_define_singleton_method(rb_cBigDecimal, "E", BigDecimal_e, 1);
+    rb_define_singleton_method(rb_cBigDecimal, "PI", BigDecimal_pi, 1);
+    rb_define_method(rb_cBigDecimal, "exp", BigDecimal_exp, 1);
+    rb_define_method(rb_cBigDecimal, "sincos", BigDecimal_sincos, 1);
+#endif /* ENABLE_TRIAL_METHOD */
+
+#ifdef ENABLE_BANG_METHOD
     rb_define_singleton_method(rb_cBigDecimal, "assign!", BigDecimal_assign, 3);
     rb_define_singleton_method(rb_cBigDecimal, "add!", BigDecimal_add3, 3);
     rb_define_singleton_method(rb_cBigDecimal, "sub!", BigDecimal_sub3, 3);
     rb_define_singleton_method(rb_cBigDecimal, "mult!", BigDecimal_mult3, 3);
     rb_define_singleton_method(rb_cBigDecimal, "div!",BigDecimal_divmod4, 4);
-#endif /* USE_MUTABLE_METHOD */
+#endif /* ENABLE_BANG_METHOD */
 }
 
 /*
  *
  *  ============================================================================
  *
- *  vp_ routines begins here
+ *  vp_ routines begin from here.
  *
  *  ============================================================================
  *
@@ -2064,7 +2080,7 @@ VpAlloc(U_LONG mx, char *szVal)
 VP_EXPORT int
 VpAsgn(Real *c, Real *a, int isw)
 {
-    U_LONG j, n;
+    U_LONG n;
     if(VpIsNaN(a)) {
         VpSetNaN(c);
         return 0;
@@ -2080,7 +2096,7 @@ VpAsgn(Real *c, Real *a, int isw)
         VpSetSign(c,(isw*VpGetSign(a)));    /* set sign */
         n =(a->Prec < c->MaxPrec) ?(a->Prec) :(c->MaxPrec);
         c->Prec = n;
-        for(j=0;j < n; ++j) c->frac[j] = a->frac[j];
+        memcpy(c->frac, a->frac, n * sizeof(U_LONG));
         /* Needs round ? */
         if(c->Prec < a->Prec) {
             VpInternalRound(c,n,(n>0)?a->frac[n-1]:0,a->frac[n]);
@@ -2093,7 +2109,6 @@ VpAsgn(Real *c, Real *a, int isw)
     return c->Prec*BASE_FIG;
 }
 
-
 /*
  *   c = a + b  when operation =  1 or 2
  *  = a - b  when operation = -1 or -2.
@@ -2602,7 +2617,7 @@ VpMult(Real *c, Real *a, Real *b)
     VpSetSign(c,VpGetSign(a)*VpGetSign(b));    /* set sign  */
     Carry = 0;
     nc = ind_c = MxIndAB;
-    for(i = 0; i <= nc; i++) c->frac[i] = 0;        /* Initialize c  */
+    memset(c->frac, 0, (nc + 1) * sizeof(U_LONG));        /* Initialize c  */
     c->Prec = nc + 1;        /* set precision */
     for(nc = 0; nc < MxIndAB; ++nc, --ind_c) {
         if(nc < MxIndB) {    /* The left triangle of the Fig. */
@@ -3113,7 +3128,7 @@ static void
 VpFormatSt(char *psz,S_INT fFmt)
 {
     U_LONG ie;
-    U_LONG i, j;
+    U_LONG i;
     S_INT nf = 0;
     char ch;
     int fDot = 0;
@@ -3131,8 +3146,7 @@ VpFormatSt(char *psz,S_INT fFmt)
         if(ch == 'E') break;
         nf++;
         if(nf > fFmt) {
-            for(j = ie; j >= i; --j)
-            psz[j + 1] = psz[j];
+            memmove(psz + i + 1, psz + i, ie - i + 1);
             ++ie;
             nf = 0;
             psz[i] = ' ';
@@ -3283,7 +3297,7 @@ VpCtoV(Real *a, char *int_chr, U_LONG ni, char *frac, U_LONG nf, char *exp_chr,
     mi = ni;
     me = ne;
     signe = 1;
-    for(i=0;i < ma;++i) a->frac[i] = 0;
+    memset(a->frac, 0, ma * sizeof(U_LONG));
     if(ne > 0) {
         i = 0;
         if(exp_chr[0] == '-') {
@@ -3398,24 +3412,51 @@ Final:
  * DBLE_FIG ... Number of digits in a double variable.
  *
  *  m -> d*10**e, 0<d<BASE
+ * [Returns]
+ *   0 ... Zero
+ *   1 ... Normal
+ *   2 ... Infinity
+ *  -1 ... NaN
  */
-VP_EXPORT void
+VP_EXPORT int
 VpVtoD(double *d, S_LONG *e, Real *m)
 {
     U_LONG ind_m, mm, fig;
     double div;
+    int    f = 1;
 
-    fig =(DBLE_FIG + BASE_FIG - 1) / BASE_FIG;
+    if(VpIsNaN(m)) {
+        *d = VpGetDoubleNaN();
+        *e = 0;
+        f = -1; /* NaN */
+        goto Exit;
+    } else
     if(VpIsPosZero(m)) {
         *d = 0.0;
         *e = 0;
+        f  = 0;
         goto Exit;
     } else
     if(VpIsNegZero(m)) {
         *d = VpGetDoubleNegZero();
         *e = 0;
+        f  = 0;
+        goto Exit;
+    } else
+    if(VpIsPosInf(m)) {
+        *d = VpGetDoublePosInf();
+        *e = 0;
+        f  = 2;
+        goto Exit;
+    } else
+    if(VpIsNegInf(m)) {
+        *d = VpGetDoubleNegInf();
+        *e = 0;
+        f  = 2;
         goto Exit;
     }
+    /* Normal number */
+    fig =(DBLE_FIG + BASE_FIG - 1) / BASE_FIG;
     ind_m = 0;
     mm = Min(fig,(m->Prec));
     *d = 0.0;
@@ -3435,7 +3476,7 @@ Exit:
         printf("   DBLE_FIG = %ld\n", DBLE_FIG);
     }
 #endif /*_DEBUG */
-    return;
+    return f;
 }
 
 /*
@@ -3479,7 +3520,7 @@ VpDtoV(Real *m, double d)
     /* Now val = 0.xxxxx*BASE**ne */
 
     mm = m->MaxPrec;
-    for(ind_m = 0;ind_m < mm;ind_m++) m->frac[ind_m] = 0;
+    memset(m->frac, 0, mm * sizeof(U_LONG));
     for(ind_m = 0;val > 0.0 && ind_m < mm;ind_m++) {
         val *=(double)((S_INT)BASE);
         i =(U_LONG) val;
@@ -3684,7 +3725,7 @@ Exit:
 VP_EXPORT void
 VpActiveRound(Real *y, Real *x, int f, int nf)
 {
-    int n,i,j,ix,ioffset;
+    int n,i,ix,ioffset;
     U_LONG v;
     U_LONG div;
 
@@ -3700,7 +3741,7 @@ VpActiveRound(Real *y, Real *x, int f, int nf)
     ix = (nf + ((int)BASE_FIG))/((int)BASE_FIG)-1;
     if(ix<0 || ((U_LONG)ix)>=y->Prec) goto Exit; /* Unable to round */
     ioffset = nf - ix*((int)BASE_FIG);
-    for(j=ix+1;j<(int)y->Prec;++j) y->frac[j] = 0;
+    memset(y->frac+ix+1, 0, (y->Prec - (ix+1)) * sizeof(U_LONG));
     /* VpNmlz(y); */
     v = y->frac[ix];
     /* drop digits after pointed digit */
@@ -3929,6 +3970,7 @@ Exit:
     return 1;
 }
 
+#ifdef ENABLE_TRIAL_METHOD
 /*
  * Calculates pi(=3.141592653589793238462........).
  */
@@ -4216,6 +4258,7 @@ Exit:
     VpFree(r);
     VpFree(z);
 }
+#endif /* ENABLE_TRIAL_METHOD */
 
 #ifdef _DEBUG
 int
diff --git a/ext/bigdecimal/bigdecimal.h b/ext/bigdecimal/bigdecimal.h
index 3debb52826..940647b446 100644
--- a/ext/bigdecimal/bigdecimal.h
+++ b/ext/bigdecimal/bigdecimal.h
@@ -131,7 +131,7 @@ VP_EXPORT S_LONG VpExponent10(Real *a);
 VP_EXPORT void VpSzMantissa(Real *a,char *psz);
 VP_EXPORT void VpToString(Real *a,char *psz,int fFmt);
 VP_EXPORT int VpCtoV(Real *a,char *int_chr,U_LONG ni,char *frac,U_LONG nf,char *exp_chr,U_LONG ne);
-VP_EXPORT void VpVtoD(double *d,S_LONG *e,Real *m);
+VP_EXPORT int VpVtoD(double *d,S_LONG *e,Real *m);
 VP_EXPORT void VpDtoV(Real *m,double d);
 VP_EXPORT void VpItoV(Real *m,S_INT ival);
 VP_EXPORT int VpSqrt(Real *y,Real *x);
diff --git a/ext/bigdecimal/bigdecimal_en.html b/ext/bigdecimal/bigdecimal_en.html
index 04dd83a429..5344720adc 100644
--- a/ext/bigdecimal/bigdecimal_en.html
+++ b/ext/bigdecimal/bigdecimal_en.html
@@ -81,21 +81,29 @@ to create BigDecimal objects,the program would like:<BR>
 <CODE><PRE>
    require 'bigdecimal'
    a=BigDecimal::new("0.123456789123456789")
-   b=BigDecimal::new("123456.78912345678",40)
+   b=BigDecimal("123456.78912345678",40)
    c=a+b
 </PRE></CODE>
 
 <H3>List of methods</H3>
-In the following explanations,n specifies the minimum number of resulting significant digits,
-not exactly but slightly excess memories will be allocated to newly created object.
 In 32 bits integer system,every 4 digits(in decimal) are computed simultaneously.
 This means the number of significant digits in BigDecimal is always a multiple of 4.
+<P>
+Some more methods are available in Ruby code (not C code). 
+To use them,just require util.rb as:
+<PRE><CODE>
+require "bigdecimal/util.rb"
+</CODE></PRE>
+String to BigDecimal conversion, BigDecimal to String conversion 
+(in "nnnnnn.mmmm" form not in "0.xxxxxEn" form) etc are defined.
+For details,see the util.rb code.
 
 <H4><U>Class methods</U></H4>
 <UL>
 <LI><B>new</B></LI><BLOCKQUOTE>
 "new" method creates a new BigDecimal object.<BR>
-a=BigDecimal::new(s[,n])<BR>
+a=BigDecimal::new(s[,n]) or<BR>
+a=BigDecimal(s[,n]) or<BR>
 where:<BR>
 s: Initial value string.<BR>
 n: Maximum number of significant digits of a. n must be a Fixnum object.
@@ -187,18 +195,6 @@ Base value used in the BigDecimal calculation.
 On 32 bits integer system,the value of BASE is 10000.<BR>
 b = BigDecimal::BASE<BR>
 </BLOCKQUOTE>
-
-<LI><B>E</B></LI><BLOCKQUOTE>
-e = BigDecimal::E(n)<BR>
-where e(=2.718281828....) is the base value of natural logarithm.<BR>
-n specifies the length of significant digits of e.
-
-</BLOCKQUOTE>
-<LI><B>PI</B></LI><BLOCKQUOTE>
-e = BigDecimal::PI(n)<BR>
-returns at least n digits of the ratio of the circumference of a circle to its diameter
-(pi=3.14159265358979....) using J.Machin's formula.<BR>
-</BLOCKQUOTE>
 </UL>
 
 <H4><U>Instance methods</U></H4>
@@ -394,14 +390,15 @@ means a = 0.xxxxxxx*10**n.
 
 </BLOCKQUOTE>
 <LI><B>to_f</B></LI><BLOCKQUOTE>
-same as dup method.
-creates a new BigDecimal object having same value.
+Creates a new Float object having (nearly) the same value.
+Use split method if you want to convert by yourself.
 </BLOCKQUOTE>
 
 </BLOCKQUOTE>
 <LI><B>sign</B></LI><BLOCKQUOTE>
-returns the 'attribute' of a.
 n = a.sign <BR>
+returns positive value if a &gt; 0,negative value if a &lt; 0,
+otherwise zero if a == 0.<BR>
 where the value of n means that a is:<BR>
 n = BigDecimal::SIGN_NaN(0) : a is NaN<BR>
 n = BigDecimal::SIGN_POSITIVE_ZERO(1) : a is +0<BR>
@@ -455,28 +452,13 @@ where "0x112344" is the address,
 '0.314E1' is the value,4 is the number of the significant digits,
 and 12 is the maximum number of the significant digits 
 the object can hold.
-
 </BLOCKQUOTE>
-<LI><B>dup</B></LI><BLOCKQUOTE>
-creates a new BigDecimal object having same value.
 
-</BLOCKQUOTE>
 <LI><B>sqrt</B></LI><BLOCKQUOTE>
 c = a.sqrt(n)<BR>
 computes square root value of a with significant digit number n at least.<BR>
-
-</BLOCKQUOTE>
-<LI><B>sincos</B></LI><BLOCKQUOTE>
-computes and returns sine and cosine value of a with significant digit number n at least.<BR>
-sin,cos = a.sincos(n)<BR>
-Computation may return bad results unless |a|<2*3.1415..... 
 </BLOCKQUOTE>
-<LI><B>exp</B></LI><BLOCKQUOTE>
-c = a.exp(n)<BR>
-computes the base of natural logarithm value(e=2.718281828....) powered by a
-with significant digit number n at least.<BR>
 
-</BLOCKQUOTE>
 <LI><B>**</B></LI><BLOCKQUOTE>
 c = a ** n<BR>
 returns the value of a powered by n.
@@ -507,6 +489,41 @@ same as ==,used in case statement.
 <LI>&gt;</LI>
 <LI>&gt;=</LI>
 </UL>
+
+<H4><U>Class methods(trial version)</U></H4>
+Following class methods are in trial stage, and not usable in default.
+Uncomment /* #define ENABLE_TRIAL_METHOD */ in bigdecimal.c, compile and install 
+again if you want to use.
+<UL>
+<LI><B>E</B></LI><BLOCKQUOTE>
+e = BigDecimal::E(n)<BR>
+where e(=2.718281828....) is the base value of natural logarithm.<BR>
+n specifies the length of significant digits of e.
+
+</BLOCKQUOTE>
+<LI><B>PI</B></LI><BLOCKQUOTE>
+e = BigDecimal::PI(n)<BR>
+returns at least n digits of the ratio of the circumference of a circle to its diameter
+(pi=3.14159265358979....) using J.Machin's formula.<BR>
+</BLOCKQUOTE>
+</UL>
+
+<H4><U>Instance methods(trial version)</U></H4>
+Following instance methods are in trial stage, and not usable in default.
+Uncomment /* #define ENABLE_TRIAL_METHOD */ in bigdecimal.c, compile and install 
+again if you want to use.
+<UL>
+<LI><B>sincos</B></LI><BLOCKQUOTE>
+computes and returns sine and cosine value of a with significant digit number n at least.<BR>
+sin,cos = a.sincos(n)<BR>
+Computation may return bad results unless |a|<2*3.1415..... 
+</BLOCKQUOTE>
+<LI><B>exp</B></LI><BLOCKQUOTE>
+c = a.exp(n)<BR>
+computes the base of natural logarithm value(e=2.718281828....) powered by a
+with significant digit number n at least.<BR>
+</BLOCKQUOTE>
+</UL>
 <HR>
 
 <H3>About 'coerce'</H3>
@@ -521,7 +538,9 @@ same as ==,used in case statement.
 BigDecimal object and the operation is performed,otherwise an error occures.</DD>
 </DL>
 
-Attention must be paid when a String is to be translated to BigDecimal.
+String is not translated to BigDecimal in default.
+Uncomment /* #define ENABLE_NUMERIC_STRING */ in bigdecimal.c, compile and install 
+again if you want to enable string to BigDecimal conversion.
 Translation stops without error at the character representing non digit.
 For instance,"10XX" is translated to 10,"XXXX" is translated to 0.<BR>
 String representing zero or infinity such as "Infinity","+Infinity","-Infinity",and "NaN" can also be translated to BigDecimal unless false is specified by mode method.<BR>
diff --git a/ext/bigdecimal/bigdecimal_ja.html b/ext/bigdecimal/bigdecimal_ja.html
index 56bebaa863..caa1326c92 100644
--- a/ext/bigdecimal/bigdecimal_ja.html
+++ b/ext/bigdecimal/bigdecimal_ja.html
@@ -84,7 +84,7 @@ bigdecimal.c,bigdecimal.h
 <PRE>
 require 'bigdecimal'
 a=BigDecimal::new("0.123456789123456789")
-b=BigDecimal::new("123456.78912345678",40)
+b=BigDecimal("123456.78912345678",40)
 c=a+b
 </PRE>
 </CODE>
@@ -92,18 +92,27 @@ c=a+b
 �Ƃ����悤�Ȋ����Ŏg�p���܂��B
 
 <H3>���\�b�h�ꗗ</H3>
-�ȉ��̂悤�ȃ��\�b�h�����p�”\�ł��B<BR>
-�L�q��ABigDecimal �I�u�W�F�N�g�� a,b,c,r�ŁAString�i������j�I�u�W�F�N�g��
- s�A������ n �ŕ\�L���܂��B�܂��A�u�L�������v�Ƃ� BigDecimal �����x��ۏ؂���
-�����ł��B�҂�����ł͂���܂���A�኱�̗]�T�������Čv�Z����܂��B�܂��A
+�ȉ��̃��\�b�h�����p�”\�ł��B
+�u�L�������v�Ƃ� BigDecimal �����x��ۏ؂��錅���ł��B
+�҂�����ł͂���܂���A�኱�̗]�T�������Čv�Z����܂��B�܂��A
 �Ⴆ�΂R�Q�r�b�g�̃V�X�e���ł͂P�O�i�łS�����Ɍv�Z���܂��B�]���āA����ł́A
 �����́u�L�������v�͂S�̔{���ƂȂ��Ă��܂��B
+<P>
+�ȉ��̃��\�b�h�ȊO�ɂ��A(C �ł͂Ȃ�) Ruby �\�[�X�̌`��
+�񋟂���Ă�����̂�����܂��B�Ⴆ�΁A�����񂩂� BigDecimal �ւ�
+�ϊ���A"0.xxxxxEn" �Ƃ����`���ł͂Ȃ� "nnnnn.mmmm" �̌`���̕�����
+�֕ϊ����郁�\�b�h��������܂��B���p����ɂ�
+<PRE><CODE>
+require "bigdecimal/util.rb"
+</CODE></PRE>
+�̂悤�ɂ��܂��B�ڍׂ� util.rb �̓��e���Q�Ƃ��ĉ������B
 
 <H4><U>�N���X���\�b�h</U></H4>
 <UL>
 <LI><B>new</B></LI><BLOCKQUOTE>
 �V���� BigDecimal �I�u�W�F�N�g�𐶐����܂��B<BR>
-a=BigDecimal::new(s[,n])<BR>
+a=BigDecimal::new(s[,n]) �܂���<BR>
+a=BigDecimal(s[,n])<BR>
 s �͏����l�𕶎���Ŏw�肵�܂��D
 n �͕K�v�ȗL�������ia �̍ő�L�������j�𐮐��Ŏw�肵�܂��B
 n �� 0 �܂��͏ȗ����ꂽ�Ƃ��́An �̒l�� s �̗L�������Ƃ݂Ȃ���܂��B
@@ -195,17 +204,6 @@ double_fig�͈ȉ��� C �v���O�����̌��ʂƓ����ł��B
 �����Ŏg�p������̒l�ł��B������ 32 �r�b�g�̏����n�ł�10000�ł��B<BR>
 b = BigDecimal::BASE<BR>
 </BLOCKQUOTE>
-
-<LI><B>E</B></LI><BLOCKQUOTE>
-���R�ΐ��̒�e(=2.718281828....)���v�Z���܂��i�����Ƀe�C���[�W�J�Łj�B<BR>
-e = BigDecimal::E(n)<BR>
-n�͕K�v�ȗL�������𐮐��Ŏw�肵�܂��B
-</BLOCKQUOTE>
-<LI><B>PI</B></LI><BLOCKQUOTE>
-�~����(=3.14159265358979....)���v�Z���܂��iJ�DMachin�̌�����p���܂��j�B<BR>
-e = BigDecimal::PI(n)<BR>
-n �͕K�v�ȗL�������𐮐��Ŏw�肵�܂��B
-</BLOCKQUOTE>
 </UL>
 
 <H4><U>�C���X�^���X���\�b�h</U></H4>
@@ -374,8 +372,9 @@ i �͒l�ɉ����� Fixnum �� Bignum �ɂȂ�܂��B
 a �� Infinity �� NaN �̂Ƃ��Ai �� nil �ɂȂ�܂��B
 </BLOCKQUOTE>
 <LI><B>to_f</B></LI><BLOCKQUOTE>
-dup �ƑS�������ł��B
-�����l�� BigDecimal �I�u�W�F�N�g�𐶐����܂��B
+Float �I�u�W�F�N�g�ɕϊ����܂��B
+��肫�ߍׂ����l���K�v�Ȃ�� split ���\�b�h�𗘗p����
+���������B
 </BLOCKQUOTE>
 <LI><B>to_s[(n)]</B></LI><BLOCKQUOTE>
 ������ɕϊ����܂�("0.xxxxxEn"�̌`�ɂȂ�܂��j�B<BR>
@@ -391,7 +390,7 @@ n = a.exponent <BR>
 </BLOCKQUOTE>
 
 <LI><B>sign</B></LI><BLOCKQUOTE>
-�l�̑�����Ԃ��܂��B
+�l����(sign &gt; 0)�A��(sign &lt; 0)�A���̑�(sigh==0)�ł��邩�̏���Ԃ��܂��B
 n = a.sign <BR>
 �Ƃ����Ƃ� n �̒l�� a ���ȉ��̂Ƃ����Ӗ����܂��B<BR>
 () �̒��̐����́A���ۂ̒l�ł�(<A HREF="#STRUCT">�u�����\���v</A>���Q��)�B<BR>
@@ -443,28 +442,6 @@ p a=BigDecimal::new("3.14",10)<BR>
 �ŏ���16�i���̓I�u�W�F�N�g�̃A�h���X�A���� '0.314E1' �͒l�A
 ����4�͌��݂̗L������(�\�����኱�傫�����Ƃ�����܂�)�A
 �Ō�̓I�u�W�F�N�g����蓾��ő包���ɂȂ�܂��B
-
-</BLOCKQUOTE>
-<LI><B>dup</B></LI><BLOCKQUOTE>
-�����l�� BigDecimal �I�u�W�F�N�g�𐶐����܂��B
-</BLOCKQUOTE>
-<LI><B>sqrt</B></LI><BLOCKQUOTE>
-a�̗L���� n ���̕������in �̕������ł͂���܂���j�B
-����܂��A�����Ƀj���[�g���@�Ōv�Z���܂��B<BR>
-c = a.sqrt(n)<BR>
-</BLOCKQUOTE>
-<LI><B>sincos</B></LI><BLOCKQUOTE>
-a �̗L���� n ���� sin �� cos �𓯎��Ɂi�e�C���[�W�J�Łj�v�Z���āA
- sin �� cos �̔z���Ԃ��܂��B
-n �͕K�v�ȗL�������ł��i n �� sin �� cos ���v�Z����킯�ł͂���܂���j�B
-<BR>
-sin,cos = a.sincos(n)<BR>
-|a|<2*3.1415....�łȂ��Ɛ������������v�Z�ł��Ȃ����Ƃ�����܂��B
-</BLOCKQUOTE>
-<LI><B>exp</B></LI><BLOCKQUOTE>
-���R�ΐ��̒�e(=2.718281828....)�� a ����v�Z���܂��B<BR>
-c = a.exp(n)<BR>
-n �͕K�v�ȗL�������ł��B
 </BLOCKQUOTE>
 <LI><B>**</B></LI><BLOCKQUOTE>
 a �� n ����v�Z���܂��B���͐����B<BR>
@@ -476,6 +453,11 @@ c = a ** n<BR>
 c = a.power(n)<BR>
 ���ʂƂ��� c �̗L������ a �� n �{�ȏ�ɂȂ�̂Œ��ӁB
 </BLOCKQUOTE>
+<LI><B>sqrt</B></LI><BLOCKQUOTE>
+a�̗L���� n ���̕������in �̕������ł͂���܂���j��
+�j���[�g���@�Ōv�Z���܂��B<BR>
+c = a.sqrt(n)<BR>
+</BLOCKQUOTE>
 
 <LI><B>&lt=&gt</B></LI><BLOCKQUOTE>
 a==b �Ȃ� 0�Aa &gt b �Ȃ� 1�Aa &lt b �Ȃ� -1 �ɂȂ�܂��B<BR>
@@ -493,11 +475,56 @@ c = a &lt=&gt b
 <LI><B>&gt</B></LI>
 <LI><B>&gt=</B></LI>
 </UL>
+
+<H4><U>(�]���i�K��)�N���X���\�b�h</U></H4>
+�ȉ��̃N���X���\�b�h�́A�܂��]���i�K�ł��̂ŁA�ʏ�ł�
+�g�p�ł��܂���B�g�p����ɂ� bigdecimal.c ��
+�u/* #define ENABLE_TRIAL_METHOD   */�v
+�̃R�����g���O���A�ăR���p�C���E�ăC���X�g�[�����K�v�ł��B
+
+<UL>
+<LI><B>E</B></LI><BLOCKQUOTE>
+���R�ΐ��̒�e(=2.718281828....)���v�Z���܂��i�����Ƀe�C���[�W�J�Łj�B<BR>
+e = BigDecimal::E(n)<BR>
+n�͕K�v�ȗL�������𐮐��Ŏw�肵�܂��B
+</BLOCKQUOTE>
+<LI><B>PI</B></LI><BLOCKQUOTE>
+�~����(=3.14159265358979....)���v�Z���܂��iJ�DMachin�̌�����p���܂��j�B<BR>
+e = BigDecimal::PI(n)<BR>
+n �͕K�v�ȗL�������𐮐��Ŏw�肵�܂��B
+</BLOCKQUOTE>
+</UL>
+
+<H4><U>(�]���i�K��)�C���X�^���X���\�b�h</U></H4>
+�ȉ��̃C���X�^���X���\�b�h�́A�܂��]���i�K�ł��̂ŁA�ʏ�ł�
+�g�p�ł��܂���B�g�p����ɂ� bigdecimal.c ��
+�u/* #define ENABLE_TRIAL_METHOD   */�v
+�̃R�����g���O���āA�ăR���p�C���E�ăC���X�g�[�����K�v�ł��B
+<UL>
+<LI><B>sincos</B></LI><BLOCKQUOTE>
+a �̗L���� n ���� sin �� cos �𓯎��Ɂi�e�C���[�W�J�Łj�v�Z���āA
+ sin �� cos �̔z���Ԃ��܂��B
+n �͕K�v�ȗL�������ł��i n �� sin �� cos ���v�Z����킯�ł͂���܂���j�B
+<BR>
+sin,cos = a.sincos(n)<BR>
+|a| &lt; 2*3.1415....�łȂ��Ɛ������������v�Z�ł��Ȃ����Ƃ�����܂��B
+</BLOCKQUOTE>
+<LI><B>exp</B></LI><BLOCKQUOTE>
+���R�ΐ��̒�e(=2.718281828....)�� a ����v�Z���܂��B<BR>
+c = a.exp(n)<BR>
+n �͕K�v�ȗL�������ł��B
+</BLOCKQUOTE>
+</UL>
+
 <H3>coerce�ɂ‚���</H3>
 BigDecimal �I�u�W�F�N�g���Z�p���Z�q�̍��ɂ���Ƃ��́ABigDecimal �I�u�W�F�N�g��
 �E�ɂ���I�u�W�F�N�g��(�K�v�Ȃ�) BigDecimal �ɕϊ����Ă���v�Z���܂��B
 �]���āABigDecimal �I�u�W�F�N�g�ȊO�ł����l���Ӗ�������̂Ȃ�E�ɒu����
-���Z�͉”\�ł��B<BR><BR>
+���Z�͉”\�ł��B<BR>
+�������A������́i�ʏ�j���l�Ɏ����ϊ����邱�Ƃ͂ł��܂���B
+������𐔒l�Ɏ����ϊ��Ɏ����ϊ��������ꍇ�� bigfloat.c ��
+�u/* #define ENABLE_NUMERIC_STRING */�v�̃R�����g���O���Ă���A
+�ăR���p�C���A�ăC���X�g�[������K�v������܂��B
 ������Ő��l��^����ꍇ�͒��ӂ��K�v�ł��B���l�ɕϊ��ł��Ȃ�����������ƁA
 �P�ɕϊ����~�߂邾���ŃG���[�ɂ͂Ȃ�܂���B"10XX"�Ȃ�P�O�A"XXXX"�͂O
 �ƈ����܂��B<BR>