Float objects represent real numbers using the native architecture‘s double-precision floating point representation.
| ROUNDS | = | INT2FIX(FLT_ROUNDS) |
| RADIX | = | INT2FIX(FLT_RADIX) |
| MANT_DIG | = | INT2FIX(DBL_MANT_DIG) |
| DIG | = | INT2FIX(DBL_DIG) |
| MIN_EXP | = | INT2FIX(DBL_MIN_EXP) |
| MAX_EXP | = | INT2FIX(DBL_MAX_EXP) |
| MIN_10_EXP | = | INT2FIX(DBL_MIN_10_EXP) |
| MAX_10_EXP | = | INT2FIX(DBL_MAX_10_EXP) |
| MIN | = | rb_float_new(DBL_MIN) |
| MAX | = | rb_float_new(DBL_MAX) |
| EPSILON | = | rb_float_new(DBL_EPSILON) |
Convert obj to a float.
/*
* call-seq:
* Float.induced_from(obj) => float
*
* Convert <code>obj</code> to a float.
*/
static VALUE
rb_flo_induced_from(klass, x)
VALUE klass, x;
{
switch (TYPE(x)) {
case T_FIXNUM:
case T_BIGNUM:
return rb_funcall(x, rb_intern("to_f"), 0);
case T_FLOAT:
return x;
default:
rb_raise(rb_eTypeError, "failed to convert %s into Float",
rb_obj_classname(x));
}
}
Return the modulo after division of flt by other.
6543.21.modulo(137) #=> 104.21 6543.21.modulo(137.24) #=> 92.9299999999996
/*
* call-seq:
* flt % other => float
* flt.modulo(other) => float
*
* Return the modulo after division of <code>flt</code> by <code>other</code>.
*
* 6543.21.modulo(137) #=> 104.21
* 6543.21.modulo(137.24) #=> 92.9299999999996
*/
static VALUE
flo_mod(x, y)
VALUE x, y;
{
double fy, mod;
switch (TYPE(y)) {
case T_FIXNUM:
fy = (double)FIX2LONG(y);
break;
case T_BIGNUM:
fy = rb_big2dbl(y);
break;
case T_FLOAT:
fy = RFLOAT(y)->value;
break;
default:
return rb_num_coerce_bin(x, y);
}
flodivmod(RFLOAT(x)->value, fy, 0, &mod);
return rb_float_new(mod);
}
Returns a new float which is the product of float and other.
/*
* call-seq:
* float * other => float
*
* Returns a new float which is the product of <code>float</code>
* and <code>other</code>.
*/
static VALUE
flo_mul(x, y)
VALUE x, y;
{
switch (TYPE(y)) {
case T_FIXNUM:
return rb_float_new(RFLOAT(x)->value * (double)FIX2LONG(y));
case T_BIGNUM:
return rb_float_new(RFLOAT(x)->value * rb_big2dbl(y));
case T_FLOAT:
return rb_float_new(RFLOAT(x)->value * RFLOAT(y)->value);
default:
return rb_num_coerce_bin(x, y);
}
}
flt ** other => float
Raises float the other power.
/*
* call-seq:
*
* flt ** other => float
*
* Raises <code>float</code> the <code>other</code> power.
*/
static VALUE
flo_pow(x, y)
VALUE x, y;
{
switch (TYPE(y)) {
case T_FIXNUM:
return rb_float_new(pow(RFLOAT(x)->value, (double)FIX2LONG(y)));
case T_BIGNUM:
return rb_float_new(pow(RFLOAT(x)->value, rb_big2dbl(y)));
case T_FLOAT:
return rb_float_new(pow(RFLOAT(x)->value, RFLOAT(y)->value));
default:
return rb_num_coerce_bin(x, y);
}
}
Returns a new float which is the sum of float and other.
/*
* call-seq:
* float + other => float
*
* Returns a new float which is the sum of <code>float</code>
* and <code>other</code>.
*/
static VALUE
flo_plus(x, y)
VALUE x, y;
{
switch (TYPE(y)) {
case T_FIXNUM:
return rb_float_new(RFLOAT(x)->value + (double)FIX2LONG(y));
case T_BIGNUM:
return rb_float_new(RFLOAT(x)->value + rb_big2dbl(y));
case T_FLOAT:
return rb_float_new(RFLOAT(x)->value + RFLOAT(y)->value);
default:
return rb_num_coerce_bin(x, y);
}
}
Returns a new float which is the difference of float and other.
/*
* call-seq:
* float + other => float
*
* Returns a new float which is the difference of <code>float</code>
* and <code>other</code>.
*/
static VALUE
flo_minus(x, y)
VALUE x, y;
{
switch (TYPE(y)) {
case T_FIXNUM:
return rb_float_new(RFLOAT(x)->value - (double)FIX2LONG(y));
case T_BIGNUM:
return rb_float_new(RFLOAT(x)->value - rb_big2dbl(y));
case T_FLOAT:
return rb_float_new(RFLOAT(x)->value - RFLOAT(y)->value);
default:
return rb_num_coerce_bin(x, y);
}
}
Returns float, negated.
/*
* call-seq:
* -float => float
*
* Returns float, negated.
*/
static VALUE
flo_uminus(flt)
VALUE flt;
{
return rb_float_new(-RFLOAT(flt)->value);
}
Returns a new float which is the result of dividing float by other.
/*
* call-seq:
* float / other => float
*
* Returns a new float which is the result of dividing
* <code>float</code> by <code>other</code>.
*/
static VALUE
flo_div(x, y)
VALUE x, y;
{
long f_y;
double d;
switch (TYPE(y)) {
case T_FIXNUM:
f_y = FIX2LONG(y);
return rb_float_new(RFLOAT(x)->value / (double)f_y);
case T_BIGNUM:
d = rb_big2dbl(y);
return rb_float_new(RFLOAT(x)->value / d);
case T_FLOAT:
return rb_float_new(RFLOAT(x)->value / RFLOAT(y)->value);
default:
return rb_num_coerce_bin(x, y);
}
}
true if flt is less than other.
/*
* call-seq:
* flt < other => true or false
*
* <code>true</code> if <code>flt</code> is less than <code>other</code>.
*/
static VALUE
flo_lt(x, y)
VALUE x, y;
{
double a, b;
a = RFLOAT(x)->value;
switch (TYPE(y)) {
case T_FIXNUM:
b = (double)FIX2LONG(y);
break;
case T_BIGNUM:
b = rb_big2dbl(y);
break;
case T_FLOAT:
b = RFLOAT(y)->value;
if (isnan(b)) return Qfalse;
break;
default:
return rb_num_coerce_relop(x, y);
}
if (isnan(a)) return Qfalse;
return (a < b)?Qtrue:Qfalse;
}
true if flt is less than or equal to other.
/*
* call-seq:
* flt <= other => true or false
*
* <code>true</code> if <code>flt</code> is less than
* or equal to <code>other</code>.
*/
static VALUE
flo_le(x, y)
VALUE x, y;
{
double a, b;
a = RFLOAT(x)->value;
switch (TYPE(y)) {
case T_FIXNUM:
b = (double)FIX2LONG(y);
break;
case T_BIGNUM:
b = rb_big2dbl(y);
break;
case T_FLOAT:
b = RFLOAT(y)->value;
if (isnan(b)) return Qfalse;
break;
default:
return rb_num_coerce_relop(x, y);
}
if (isnan(a)) return Qfalse;
return (a <= b)?Qtrue:Qfalse;
}
Returns -1, 0, or +1 depending on whether flt is less than, equal to, or greater than numeric. This is the basis for the tests in Comparable.
/*
* call-seq:
* flt <=> numeric => -1, 0, +1
*
* Returns -1, 0, or +1 depending on whether <i>flt</i> is less than,
* equal to, or greater than <i>numeric</i>. This is the basis for the
* tests in <code>Comparable</code>.
*/
static VALUE
flo_cmp(x, y)
VALUE x, y;
{
double a, b;
a = RFLOAT(x)->value;
switch (TYPE(y)) {
case T_FIXNUM:
b = (double)FIX2LONG(y);
break;
case T_BIGNUM:
b = rb_big2dbl(y);
break;
case T_FLOAT:
b = RFLOAT(y)->value;
break;
default:
return rb_num_coerce_cmp(x, y);
}
return rb_dbl_cmp(a, b);
}
Returns true only if obj has the same value as flt. Contrast this with Float#eql?, which requires obj to be a Float.
1.0 == 1 #=> true
/*
* call-seq:
* flt == obj => true or false
*
* Returns <code>true</code> only if <i>obj</i> has the same value
* as <i>flt</i>. Contrast this with <code>Float#eql?</code>, which
* requires <i>obj</i> to be a <code>Float</code>.
*
* 1.0 == 1 #=> true
*
*/
static VALUE
flo_eq(x, y)
VALUE x, y;
{
volatile double a, b;
switch (TYPE(y)) {
case T_FIXNUM:
b = FIX2LONG(y);
break;
case T_BIGNUM:
b = rb_big2dbl(y);
break;
case T_FLOAT:
b = RFLOAT(y)->value;
if (isnan(b)) return Qfalse;
break;
default:
return num_equal(x, y);
}
a = RFLOAT(x)->value;
if (isnan(a)) return Qfalse;
return (a == b)?Qtrue:Qfalse;
}
true if flt is greater than other.
/*
* call-seq:
* flt > other => true or false
*
* <code>true</code> if <code>flt</code> is greater than <code>other</code>.
*/
static VALUE
flo_gt(x, y)
VALUE x, y;
{
double a, b;
a = RFLOAT(x)->value;
switch (TYPE(y)) {
case T_FIXNUM:
b = (double)FIX2LONG(y);
break;
case T_BIGNUM:
b = rb_big2dbl(y);
break;
case T_FLOAT:
b = RFLOAT(y)->value;
if (isnan(b)) return Qfalse;
break;
default:
return rb_num_coerce_relop(x, y);
}
if (isnan(a)) return Qfalse;
return (a > b)?Qtrue:Qfalse;
}
true if flt is greater than or equal to other.
/*
* call-seq:
* flt >= other => true or false
*
* <code>true</code> if <code>flt</code> is greater than
* or equal to <code>other</code>.
*/
static VALUE
flo_ge(x, y)
VALUE x, y;
{
double a, b;
a = RFLOAT(x)->value;
switch (TYPE(y)) {
case T_FIXNUM:
b = (double)FIX2LONG(y);
break;
case T_BIGNUM:
b = rb_big2dbl(y);
break;
case T_FLOAT:
b = RFLOAT(y)->value;
if (isnan(b)) return Qfalse;
break;
default:
return rb_num_coerce_relop(x, y);
}
if (isnan(a)) return Qfalse;
return (a >= b)?Qtrue:Qfalse;
}
Returns the absolute value of flt.
(-34.56).abs #=> 34.56 -34.56.abs #=> 34.56
/*
* call-seq:
* flt.abs => float
*
* Returns the absolute value of <i>flt</i>.
*
* (-34.56).abs #=> 34.56
* -34.56.abs #=> 34.56
*
*/
static VALUE
flo_abs(flt)
VALUE flt;
{
double val = fabs(RFLOAT(flt)->value);
return rb_float_new(val);
}
Returns the smallest Integer greater than or equal to flt.
1.2.ceil #=> 2 2.0.ceil #=> 2 (-1.2).ceil #=> -1 (-2.0).ceil #=> -2
/*
* call-seq:
* flt.ceil => integer
*
* Returns the smallest <code>Integer</code> greater than or equal to
* <i>flt</i>.
*
* 1.2.ceil #=> 2
* 2.0.ceil #=> 2
* (-1.2).ceil #=> -1
* (-2.0).ceil #=> -2
*/
static VALUE
flo_ceil(num)
VALUE num;
{
double f = ceil(RFLOAT(num)->value);
long val;
if (!FIXABLE(f)) {
return rb_dbl2big(f);
}
val = f;
return LONG2FIX(val);
}
MISSING: documentation
/*
* MISSING: documentation
*/
static VALUE
flo_coerce(x, y)
VALUE x, y;
{
return rb_assoc_new(rb_Float(y), x);
}
See Numeric#divmod.
/*
* call-seq:
* flt.divmod(numeric) => array
*
* See <code>Numeric#divmod</code>.
*/
static VALUE
flo_divmod(x, y)
VALUE x, y;
{
double fy, div, mod, val;
volatile VALUE a, b;
switch (TYPE(y)) {
case T_FIXNUM:
fy = (double)FIX2LONG(y);
break;
case T_BIGNUM:
fy = rb_big2dbl(y);
break;
case T_FLOAT:
fy = RFLOAT(y)->value;
break;
default:
return rb_num_coerce_bin(x, y);
}
flodivmod(RFLOAT(x)->value, fy, &div, &mod);
if (FIXABLE(div)) {
val = round(div);
a = LONG2FIX(val);
}
else {
a = rb_dbl2big(div);
}
b = rb_float_new(mod);
return rb_assoc_new(a, b);
}
Returns true only if obj is a Float with the same value as flt. Contrast this with Float#==, which performs type conversions.
1.0.eql?(1) #=> false
/*
* call-seq:
* flt.eql?(obj) => true or false
*
* Returns <code>true</code> only if <i>obj</i> is a
* <code>Float</code> with the same value as <i>flt</i>. Contrast this
* with <code>Float#==</code>, which performs type conversions.
*
* 1.0.eql?(1) #=> false
*/
static VALUE
flo_eql(x, y)
VALUE x, y;
{
if (TYPE(y) == T_FLOAT) {
double a = RFLOAT(x)->value;
double b = RFLOAT(y)->value;
if (isnan(a) || isnan(b)) return Qfalse;
if (a == b) return Qtrue;
}
return Qfalse;
}
Returns true if flt is a valid IEEE floating point number (it is not infinite, and nan? is false).
/*
* call-seq:
* flt.finite? -> true or false
*
* Returns <code>true</code> if <i>flt</i> is a valid IEEE floating
* point number (it is not infinite, and <code>nan?</code> is
* <code>false</code>).
*
*/
static VALUE
flo_is_finite_p(num)
VALUE num;
{
double value = RFLOAT(num)->value;
#if HAVE_FINITE
if (!finite(value))
return Qfalse;
#else
if (isinf(value) || isnan(value))
return Qfalse;
#endif
return Qtrue;
}
Returns the largest integer less than or equal to flt.
1.2.floor #=> 1 2.0.floor #=> 2 (-1.2).floor #=> -2 (-2.0).floor #=> -2
/*
* call-seq:
* flt.floor => integer
*
* Returns the largest integer less than or equal to <i>flt</i>.
*
* 1.2.floor #=> 1
* 2.0.floor #=> 2
* (-1.2).floor #=> -2
* (-2.0).floor #=> -2
*/
static VALUE
flo_floor(num)
VALUE num;
{
double f = floor(RFLOAT(num)->value);
long val;
if (!FIXABLE(f)) {
return rb_dbl2big(f);
}
val = f;
return LONG2FIX(val);
}
Returns a hash code for this float.
/*
* call-seq:
* flt.hash => integer
*
* Returns a hash code for this float.
*/
static VALUE
flo_hash(num)
VALUE num;
{
double d;
char *c;
int i, hash;
d = RFLOAT(num)->value;
if (d == 0) d = fabs(d);
c = (char*)&d;
for (hash=0, i=0; i<sizeof(double);i++) {
hash = (hash * 971) ^ (unsigned char)c[i];
}
if (hash < 0) hash = -hash;
return INT2FIX(hash);
}
Returns nil, -1, or +1 depending on whether flt is finite, -infinity, or +infinity.
(0.0).infinite? #=> nil (-1.0/0.0).infinite? #=> -1 (+1.0/0.0).infinite? #=> 1
/*
* call-seq:
* flt.infinite? -> nil, -1, +1
*
* Returns <code>nil</code>, -1, or +1 depending on whether <i>flt</i>
* is finite, -infinity, or +infinity.
*
* (0.0).infinite? #=> nil
* (-1.0/0.0).infinite? #=> -1
* (+1.0/0.0).infinite? #=> 1
*/
static VALUE
flo_is_infinite_p(num)
VALUE num;
{
double value = RFLOAT(num)->value;
if (isinf(value)) {
return INT2FIX( value < 0 ? -1 : 1 );
}
return Qnil;
}
Return the modulo after division of flt by other.
6543.21.modulo(137) #=> 104.21 6543.21.modulo(137.24) #=> 92.9299999999996
/*
* call-seq:
* flt % other => float
* flt.modulo(other) => float
*
* Return the modulo after division of <code>flt</code> by <code>other</code>.
*
* 6543.21.modulo(137) #=> 104.21
* 6543.21.modulo(137.24) #=> 92.9299999999996
*/
static VALUE
flo_mod(x, y)
VALUE x, y;
{
double fy, mod;
switch (TYPE(y)) {
case T_FIXNUM:
fy = (double)FIX2LONG(y);
break;
case T_BIGNUM:
fy = rb_big2dbl(y);
break;
case T_FLOAT:
fy = RFLOAT(y)->value;
break;
default:
return rb_num_coerce_bin(x, y);
}
flodivmod(RFLOAT(x)->value, fy, 0, &mod);
return rb_float_new(mod);
}
Returns true if flt is an invalid IEEE floating point number.
a = -1.0 #=> -1.0 a.nan? #=> false a = 0.0/0.0 #=> NaN a.nan? #=> true
/*
* call-seq:
* flt.nan? -> true or false
*
* Returns <code>true</code> if <i>flt</i> is an invalid IEEE floating
* point number.
*
* a = -1.0 #=> -1.0
* a.nan? #=> false
* a = 0.0/0.0 #=> NaN
* a.nan? #=> true
*/
static VALUE
flo_is_nan_p(num)
VALUE num;
{
double value = RFLOAT(num)->value;
return isnan(value) ? Qtrue : Qfalse;
}
Rounds flt to the nearest integer. Equivalent to:
def round
return (self+0.5).floor if self > 0.0
return (self-0.5).ceil if self < 0.0
return 0
end
1.5.round #=> 2
(-1.5).round #=> -2
/*
* call-seq:
* flt.round => integer
*
* Rounds <i>flt</i> to the nearest integer. Equivalent to:
*
* def round
* return (self+0.5).floor if self > 0.0
* return (self-0.5).ceil if self < 0.0
* return 0
* end
*
* 1.5.round #=> 2
* (-1.5).round #=> -2
*
*/
static VALUE
flo_round(num)
VALUE num;
{
double f = RFLOAT(num)->value;
long val;
f = round(f);
if (!FIXABLE(f)) {
return rb_dbl2big(f);
}
val = f;
return LONG2FIX(val);
}
As flt is already a float, returns self.
/*
* call-seq:
* flt.to_f => flt
*
* As <code>flt</code> is already a float, returns <i>self</i>.
*/
static VALUE
flo_to_f(num)
VALUE num;
{
return num;
}
Returns flt truncated to an Integer.
/*
* call-seq:
* flt.to_i => integer
* flt.to_int => integer
* flt.truncate => integer
*
* Returns <i>flt</i> truncated to an <code>Integer</code>.
*/
static VALUE
flo_truncate(num)
VALUE num;
{
double f = RFLOAT(num)->value;
long val;
if (f > 0.0) f = floor(f);
if (f < 0.0) f = ceil(f);
if (!FIXABLE(f)) {
return rb_dbl2big(f);
}
val = f;
return LONG2FIX(val);
}
Returns flt truncated to an Integer.
/*
* call-seq:
* flt.to_i => integer
* flt.to_int => integer
* flt.truncate => integer
*
* Returns <i>flt</i> truncated to an <code>Integer</code>.
*/
static VALUE
flo_truncate(num)
VALUE num;
{
double f = RFLOAT(num)->value;
long val;
if (f > 0.0) f = floor(f);
if (f < 0.0) f = ceil(f);
if (!FIXABLE(f)) {
return rb_dbl2big(f);
}
val = f;
return LONG2FIX(val);
}
Returns a string containing a representation of self. As well as a fixed or exponential form of the number, the call may return ``NaN’’, ``Infinity’’, and ``-Infinity’’.
/*
* call-seq:
* flt.to_s => string
*
* Returns a string containing a representation of self. As well as a
* fixed or exponential form of the number, the call may return
* ``<code>NaN</code>'', ``<code>Infinity</code>'', and
* ``<code>-Infinity</code>''.
*/
static VALUE
flo_to_s(flt)
VALUE flt;
{
char buf[32];
double value = RFLOAT(flt)->value;
char *p, *e;
if (isinf(value))
return rb_str_new2(value < 0 ? "-Infinity" : "Infinity");
else if(isnan(value))
return rb_str_new2("NaN");
sprintf(buf, "%#.15g", value); /* ensure to print decimal point */
if (!(e = strchr(buf, 'e'))) {
e = buf + strlen(buf);
}
if (!ISDIGIT(e[-1])) { /* reformat if ended with decimal point (ex 111111111111111.) */
sprintf(buf, "%#.14e", value);
if (!(e = strchr(buf, 'e'))) {
e = buf + strlen(buf);
}
}
p = e;
while (p[-1]=='0' && ISDIGIT(p[-2]))
p--;
memmove(p, e, strlen(e)+1);
return rb_str_new2(buf);
}
Returns flt truncated to an Integer.
/*
* call-seq:
* flt.to_i => integer
* flt.to_int => integer
* flt.truncate => integer
*
* Returns <i>flt</i> truncated to an <code>Integer</code>.
*/
static VALUE
flo_truncate(num)
VALUE num;
{
double f = RFLOAT(num)->value;
long val;
if (f > 0.0) f = floor(f);
if (f < 0.0) f = ceil(f);
if (!FIXABLE(f)) {
return rb_dbl2big(f);
}
val = f;
return LONG2FIX(val);
}