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# Float

`Float` objects represent real numbers using the native architecture's double-precision floating point representation.

### Public Instance Methods

flt % other => float click to toggle source

Return the modulo after division of `flt` by `other`.

```6543.21.modulo(137)      #=> 104.21
6543.21.modulo(137.24)   #=> 92.9299999999996
```
```
static VALUE
flo_mod(VALUE x, VALUE 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_VALUE(y);
break;
default:
return rb_num_coerce_bin(x, y, '%');
}
flodivmod(RFLOAT_VALUE(x), fy, 0, &mod);
return DBL2NUM(mod);
}
```
float * other => float click to toggle source

Returns a new float which is the product of `float` and `other`.

```
static VALUE
flo_mul(VALUE x, VALUE y)
{
switch (TYPE(y)) {
case T_FIXNUM:
return DBL2NUM(RFLOAT_VALUE(x) * (double)FIX2LONG(y));
case T_BIGNUM:
return DBL2NUM(RFLOAT_VALUE(x) * rb_big2dbl(y));
case T_FLOAT:
return DBL2NUM(RFLOAT_VALUE(x) * RFLOAT_VALUE(y));
default:
return rb_num_coerce_bin(x, y, '*');
}
}
```
flt ** other => float click to toggle source

Raises `float` the `other` power.

```
static VALUE
flo_pow(VALUE x, VALUE y)
{
switch (TYPE(y)) {
case T_FIXNUM:
return DBL2NUM(pow(RFLOAT_VALUE(x), (double)FIX2LONG(y)));
case T_BIGNUM:
return DBL2NUM(pow(RFLOAT_VALUE(x), rb_big2dbl(y)));
case T_FLOAT:
return DBL2NUM(pow(RFLOAT_VALUE(x), RFLOAT_VALUE(y)));
default:
return rb_num_coerce_bin(x, y, rb_intern("**"));
}
}
```
float + other => float click to toggle source

Returns a new float which is the sum of `float` and `other`.

```
static VALUE
flo_plus(VALUE x, VALUE y)
{
switch (TYPE(y)) {
case T_FIXNUM:
return DBL2NUM(RFLOAT_VALUE(x) + (double)FIX2LONG(y));
case T_BIGNUM:
return DBL2NUM(RFLOAT_VALUE(x) + rb_big2dbl(y));
case T_FLOAT:
return DBL2NUM(RFLOAT_VALUE(x) + RFLOAT_VALUE(y));
default:
return rb_num_coerce_bin(x, y, '+');
}
}
```
float + other => float click to toggle source

Returns a new float which is the difference of `float` and `other`.

```
static VALUE
flo_minus(VALUE x, VALUE y)
{
switch (TYPE(y)) {
case T_FIXNUM:
return DBL2NUM(RFLOAT_VALUE(x) - (double)FIX2LONG(y));
case T_BIGNUM:
return DBL2NUM(RFLOAT_VALUE(x) - rb_big2dbl(y));
case T_FLOAT:
return DBL2NUM(RFLOAT_VALUE(x) - RFLOAT_VALUE(y));
default:
return rb_num_coerce_bin(x, y, '-');
}
}
```
-float => float click to toggle source

Returns float, negated.

```
static VALUE
flo_uminus(VALUE flt)
{
return DBL2NUM(-RFLOAT_VALUE(flt));
}
```
float / other => float click to toggle source

Returns a new float which is the result of dividing `float` by `other`.

```
static VALUE
flo_div(VALUE x, VALUE y)
{
long f_y;
double d;

switch (TYPE(y)) {
case T_FIXNUM:
f_y = FIX2LONG(y);
return DBL2NUM(RFLOAT_VALUE(x) / (double)f_y);
case T_BIGNUM:
d = rb_big2dbl(y);
return DBL2NUM(RFLOAT_VALUE(x) / d);
case T_FLOAT:
return DBL2NUM(RFLOAT_VALUE(x) / RFLOAT_VALUE(y));
default:
return rb_num_coerce_bin(x, y, '/');
}
}
```
flt < other => true or false click to toggle source

`true` if `flt` is less than `other`.

```
static VALUE
flo_lt(VALUE x, VALUE y)
{
double a, b;

a = RFLOAT_VALUE(x);
switch (TYPE(y)) {
case T_FIXNUM:
b = (double)FIX2LONG(y);
break;

case T_BIGNUM:
b = rb_big2dbl(y);
break;

case T_FLOAT:
b = RFLOAT_VALUE(y);
if (isnan(b)) return Qfalse;
break;

default:
return rb_num_coerce_relop(x, y, '<');
}
if (isnan(a)) return Qfalse;
return (a < b)?Qtrue:Qfalse;
}
```
flt <= other => true or false click to toggle source

`true` if `flt` is less than or equal to `other`.

```
static VALUE
flo_le(VALUE x, VALUE y)
{
double a, b;

a = RFLOAT_VALUE(x);
switch (TYPE(y)) {
case T_FIXNUM:
b = (double)FIX2LONG(y);
break;

case T_BIGNUM:
b = rb_big2dbl(y);
break;

case T_FLOAT:
b = RFLOAT_VALUE(y);
if (isnan(b)) return Qfalse;
break;

default:
return rb_num_coerce_relop(x, y, rb_intern("<="));
}
if (isnan(a)) return Qfalse;
return (a <= b)?Qtrue:Qfalse;
}
```
flt <=> numeric => -1, 0, +1 click to toggle source

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`.

```
static VALUE
flo_cmp(VALUE x, VALUE y)
{
double a, b;

a = RFLOAT_VALUE(x);
if (isnan(a)) return Qnil;
switch (TYPE(y)) {
case T_FIXNUM:
b = (double)FIX2LONG(y);
break;

case T_BIGNUM:
if (isinf(a)) {
if (a > 0.0) return INT2FIX(1);
else return INT2FIX(-1);
}
b = rb_big2dbl(y);
break;

case T_FLOAT:
b = RFLOAT_VALUE(y);
break;

default:
if (isinf(a) && (!rb_respond_to(y, rb_intern("infinite?")) ||
!RTEST(rb_funcall(y, rb_intern("infinite?"), 0, 0)))) {
if (a > 0.0) return INT2FIX(1);
return INT2FIX(-1);
}
return rb_num_coerce_cmp(x, y, rb_intern("<=>"));
}
return rb_dbl_cmp(a, b);
}
```
flt == obj => true or false click to toggle source

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
```
```
static VALUE
flo_eq(VALUE x, VALUE 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_VALUE(y);
if (isnan(b)) return Qfalse;
break;
default:
return num_equal(x, y);
}
a = RFLOAT_VALUE(x);
if (isnan(a)) return Qfalse;
return (a == b)?Qtrue:Qfalse;
}
```
flt == obj => true or false click to toggle source

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
```
```
static VALUE
flo_eq(VALUE x, VALUE 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_VALUE(y);
if (isnan(b)) return Qfalse;
break;
default:
return num_equal(x, y);
}
a = RFLOAT_VALUE(x);
if (isnan(a)) return Qfalse;
return (a == b)?Qtrue:Qfalse;
}
```
flt > other => true or false click to toggle source

`true` if `flt` is greater than `other`.

```
static VALUE
flo_gt(VALUE x, VALUE y)
{
double a, b;

a = RFLOAT_VALUE(x);
switch (TYPE(y)) {
case T_FIXNUM:
b = (double)FIX2LONG(y);
break;

case T_BIGNUM:
b = rb_big2dbl(y);
break;

case T_FLOAT:
b = RFLOAT_VALUE(y);
if (isnan(b)) return Qfalse;
break;

default:
return rb_num_coerce_relop(x, y, '>');
}
if (isnan(a)) return Qfalse;
return (a > b)?Qtrue:Qfalse;
}
```
flt >= other => true or false click to toggle source

`true` if `flt` is greater than or equal to `other`.

```
static VALUE
flo_ge(VALUE x, VALUE y)
{
double a, b;

a = RFLOAT_VALUE(x);
switch (TYPE(y)) {
case T_FIXNUM:
b = (double)FIX2LONG(y);
break;

case T_BIGNUM:
b = rb_big2dbl(y);
break;

case T_FLOAT:
b = RFLOAT_VALUE(y);
if (isnan(b)) return Qfalse;
break;

default:
return rb_num_coerce_relop(x, y, rb_intern(">="));
}
if (isnan(a)) return Qfalse;
return (a >= b)?Qtrue:Qfalse;
}
```
abs => float click to toggle source

Returns the absolute value of flt.

```(-34.56).abs   #=> 34.56
-34.56.abs     #=> 34.56
```
```
static VALUE
flo_abs(VALUE flt)
{
double val = fabs(RFLOAT_VALUE(flt));
return DBL2NUM(val);
}
```
angle → 0 or float click to toggle source

Returns 0 if the value is positive, pi otherwise.

```
static VALUE
float_arg(VALUE self)
{
if (isnan(RFLOAT_VALUE(self)))
return self;
return rb_call_super(0, 0);
}
```
arg → 0 or float click to toggle source

Returns 0 if the value is positive, pi otherwise.

```
static VALUE
float_arg(VALUE self)
{
if (isnan(RFLOAT_VALUE(self)))
return self;
return rb_call_super(0, 0);
}
```
ceil => integer click to toggle source

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
```
```
static VALUE
flo_ceil(VALUE num)
{
double f = ceil(RFLOAT_VALUE(num));
long val;

if (!FIXABLE(f)) {
return rb_dbl2big(f);
}
val = f;
return LONG2FIX(val);
}
```
coerce(p1) click to toggle source

MISSING: documentation

```
static VALUE
flo_coerce(VALUE x, VALUE y)
{
return rb_assoc_new(rb_Float(y), x);
}
```
denominator() click to toggle source
```
static VALUE
float_denominator(VALUE self)
{
double d = RFLOAT_VALUE(self);
if (isinf(d) || isnan(d))
return INT2FIX(1);
return rb_call_super(0, 0);
}
```
divmod(numeric) => array click to toggle source

See `Numeric#divmod`.

```
static VALUE
flo_divmod(VALUE x, VALUE y)
{
double fy, div, mod;
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_VALUE(y);
break;
default:
return rb_num_coerce_bin(x, y, rb_intern("divmod"));
}
flodivmod(RFLOAT_VALUE(x), fy, &div, &mod);
a = dbl2ival(div);
b = DBL2NUM(mod);
return rb_assoc_new(a, b);
}
```
eql?(obj) => true or false click to toggle source

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
```
```
static VALUE
flo_eql(VALUE x, VALUE y)
{
if (TYPE(y) == T_FLOAT) {
double a = RFLOAT_VALUE(x);
double b = RFLOAT_VALUE(y);

if (isnan(a) || isnan(b)) return Qfalse;
if (a == b) return Qtrue;
}
return Qfalse;
}
```
fdiv(p1) click to toggle source
```
static VALUE
flo_quo(VALUE x, VALUE y)
{
return rb_funcall(x, '/', 1, y);
}
```
finite? → true or false click to toggle source

Returns `true` if flt is a valid IEEE floating point number (it is not infinite, and `nan?` is `false`).

```
static VALUE
flo_is_finite_p(VALUE num)
{
double value = RFLOAT_VALUE(num);

#if HAVE_FINITE
if (!finite(value))
return Qfalse;
#else
if (isinf(value) || isnan(value))
return Qfalse;
#endif

return Qtrue;
}
```
floor => integer click to toggle source

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
```
```
static VALUE
flo_floor(VALUE num)
{
double f = floor(RFLOAT_VALUE(num));
long val;

if (!FIXABLE(f)) {
return rb_dbl2big(f);
}
val = f;
return LONG2FIX(val);
}
```
hash => integer click to toggle source

Returns a hash code for this float.

```
static VALUE
flo_hash(VALUE num)
{
double d;
int hash;

d = RFLOAT_VALUE(num);
/* normalize -0.0 to 0.0 */
if (d == 0.0) d = 0.0;
hash = rb_memhash(&d, sizeof(d));
return INT2FIX(hash);
}
```
infinite? → nil, -1, +1 click to toggle source

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
```
```
static VALUE
flo_is_infinite_p(VALUE num)
{
double value = RFLOAT_VALUE(num);

if (isinf(value)) {
return INT2FIX( value < 0 ? -1 : 1 );
}

return Qnil;
}
```
abs => float click to toggle source

Returns the absolute value of flt.

```(-34.56).abs   #=> 34.56
-34.56.abs     #=> 34.56
```
```
static VALUE
flo_abs(VALUE flt)
{
double val = fabs(RFLOAT_VALUE(flt));
return DBL2NUM(val);
}
```
modulo(other) => float click to toggle source

Return the modulo after division of `flt` by `other`.

```6543.21.modulo(137)      #=> 104.21
6543.21.modulo(137.24)   #=> 92.9299999999996
```
```
static VALUE
flo_mod(VALUE x, VALUE 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_VALUE(y);
break;
default:
return rb_num_coerce_bin(x, y, '%');
}
flodivmod(RFLOAT_VALUE(x), fy, 0, &mod);
return DBL2NUM(mod);
}
```
nan? → true or false click to toggle source

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
```
```
static VALUE
flo_is_nan_p(VALUE num)
{
double value = RFLOAT_VALUE(num);

return isnan(value) ? Qtrue : Qfalse;
}
```
numerator() click to toggle source
```
static VALUE
float_numerator(VALUE self)
{
double d = RFLOAT_VALUE(self);
if (isinf(d) || isnan(d))
return self;
return rb_call_super(0, 0);
}
```
phase → 0 or float click to toggle source

Returns 0 if the value is positive, pi otherwise.

```
static VALUE
float_arg(VALUE self)
{
if (isnan(RFLOAT_VALUE(self)))
return self;
return rb_call_super(0, 0);
}
```
quo(p1) click to toggle source
```
static VALUE
flo_quo(VALUE x, VALUE y)
{
return rb_funcall(x, '/', 1, y);
}
```
round([ndigits]) => integer or float click to toggle source

Rounds flt to a given precision in decimal digits (default 0 digits). Precision may be negative. Returns a a floating point number when ndigits is more than one.

```1.5.round      #=> 2
(-1.5).round   #=> -2
```
```
static VALUE
flo_round(int argc, VALUE *argv, VALUE num)
{
VALUE nd;
double number, f;
int ndigits = 0, i;
long val;

if (argc > 0 && rb_scan_args(argc, argv, "01", &nd) == 1) {
ndigits = NUM2INT(nd);
}
number  = RFLOAT_VALUE(num);
f = 1.0;
i = abs(ndigits);
while  (--i >= 0)
f = f*10.0;

if (isinf(f)) {
if (ndigits < 0) number = 0;
}
else {
if (ndigits < 0) number /= f;
else number *= f;
number = round(number);
if (ndigits < 0) number *= f;
else number /= f;
}

if (ndigits > 0) return DBL2NUM(number);

if (!FIXABLE(number)) {
return rb_dbl2big(number);
}
val = number;
return LONG2FIX(val);
}
```
to_f => flt click to toggle source

As `flt` is already a float, returns self.

```
static VALUE
flo_to_f(VALUE num)
{
return num;
}
```
to_i => integer click to toggle source
to_int => integer

Returns flt truncated to an `Integer`.

```
static VALUE
flo_truncate(VALUE num)
{
double f = RFLOAT_VALUE(num);
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);
}
```
to_int => integer click to toggle source

Returns flt truncated to an `Integer`.

```
static VALUE
flo_truncate(VALUE num)
{
double f = RFLOAT_VALUE(num);
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);
}
```
to_r() click to toggle source
```
static VALUE
float_to_r(VALUE self)
{
VALUE f, n;

float_decode_internal(self, &f, &n);
}
```
to_s => string click to toggle source

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`''.

```
static VALUE
flo_to_s(VALUE flt)
{
char buf[32];
double value = RFLOAT_VALUE(flt);
char *p, *e;

if (isinf(value))
return rb_usascii_str_new2(value < 0 ? "-Infinity" : "Infinity");
else if(isnan(value))
return rb_usascii_str_new2("NaN");

snprintf(buf, sizeof(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.) */
snprintf(buf, sizeof(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_usascii_str_new2(buf);
}
```
truncate => integer click to toggle source

Returns flt truncated to an `Integer`.

```
static VALUE
flo_truncate(VALUE num)
{
double f = RFLOAT_VALUE(num);
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);
}
```
zero? → true or false click to toggle source

Returns `true` if flt is 0.0.

```
static VALUE
flo_zero_p(VALUE num)
{
if (RFLOAT_VALUE(num) == 0.0) {
return Qtrue;
}
return Qfalse;
}
```