Class: Float
| Relationships & Source Files | |
| Super Chains via Extension / Inclusion / Inheritance | |
| Class Chain: 
          self,
           ::Numeric | |
| Instance Chain: 
          self,
           ::Numeric,::Comparable | |
| Inherits: | Numeric | 
| Defined in: | numeric.c, complex.c, numeric.rb, rational.c | 
Overview
A Float object represents a sometimes-inexact real number using the native architecture’s double-precision floating point representation.
Floating point has a different arithmetic and is an inexact number. So you should know its esoteric system. See following:
You can create a Float object explicitly with:
You can convert certain objects to Floats with:
- 
Method #Float.
What’s Here
First, what’s elsewhere. Class Float:
- 
Inherits from class Numeric. 
Here, class Float provides methods for:
Querying
- 
#finite?: Returns whether selfis finite.
- 
#hash: Returns the integer hash code for self.
- 
#infinite?: Returns whether selfis infinite.
- 
#nan?: Returns whether selfis a NaN (not-a-number).
Comparing
- 
#<: Returns whether selfis less than the given value.
- 
#<=: Returns whether selfis less than or equal to the given value.
- 
#<=>: Returns a number indicating whether selfis less than, equal to, or greater than the given value.
- 
#== (aliased as #=== and #eql?): Returns whether selfis equal to the given value.
- 
#>: Returns whether selfis greater than the given value.
- 
#>=: Returns whether selfis greater than or equal to the given value.
Converting
- 
#% (aliased as #modulo): Returns selfmodulo the given value.
- 
#*: Returns the product of selfand the given value.
- 
#**: Returns the value of selfraised to the power of the given value.
- 
#+: Returns the sum of selfand the given value.
- 
#-: Returns the difference of selfand the given value.
- 
#/: Returns the quotient of selfand the given value.
- 
#ceil: Returns the smallest number greater than or equal to self.
- 
#coerce: Returns a 2-element array containing the given value converted to a Float and {self}
- 
#divmod: Returns a 2-element array containing the quotient and remainder results of dividing selfby the given value.
- 
#fdiv: Returns the Floatresult of dividingselfby the given value.
- 
#floor: Returns the greatest number smaller than or equal to self.
- 
#next_float: Returns the next-larger representable Float. 
- 
#prev_float: Returns the next-smaller representable Float. 
- 
#quo: Returns the quotient from dividing selfby the given value.
- 
#round: Returns selfrounded to the nearest value, to a given precision.
- 
#to_i (aliased as #to_int): Returns selftruncated to an::Integer.
- 
#to_s (aliased as #inspect): Returns a string containing the place-value representation of selfin the given radix.
- 
#truncate: Returns selftruncated to a given precision.
Constant Summary
- 
    DIG =
    # File 'numeric.c', line 6316The minimum number of significant decimal digits in a double-precision floating point. Usually defaults to 15. INT2FIX(DBL_DIG) 
- 
    EPSILON =
    # File 'numeric.c', line 6368The difference between 1 and the smallest double-precision floating point number greater than 1. Usually defaults to 2.2204460492503131e-16. DBL2NUM(DBL_EPSILON) 
- 
    INFINITY =
    # File 'numeric.c', line 6372An expression representing positive infinity. DBL2NUM(HUGE_VAL) 
- 
    MANT_DIG =
    # File 'numeric.c', line 6309The number of base digits for the doubledata type.Usually defaults to 53. INT2FIX(DBL_MANT_DIG) 
- 
    MAX =
    # File 'numeric.c', line 6361The largest possible integer in a double-precision floating point number. Usually defaults to 1.7976931348623157e+308. DBL2NUM(DBL_MAX) 
- 
    MAX_10_EXP =
    # File 'numeric.c', line 6344The largest positive exponent in a double-precision floating point where 10 raised to this power minus 1. Usually defaults to 308. INT2FIX(DBL_MAX_10_EXP) 
- 
    MAX_EXP =
    # File 'numeric.c', line 6330The largest possible exponent value in a double-precision floating point. Usually defaults to 1024. INT2FIX(DBL_MAX_EXP) 
- 
    MIN =
    # File 'numeric.c', line 6355:MIN. 0.0.next_float returns the smallest positive floating point number including denormalized numbers.The smallest positive normalized number in a double-precision floating point. Usually defaults to 2.2250738585072014e-308. If the platform supports denormalized numbers, there are numbers between zero and Float 
- 
    MIN_10_EXP =
    # File 'numeric.c', line 6337The smallest negative exponent in a double-precision floating point where 10 raised to this power minus 1. Usually defaults to -307. INT2FIX(DBL_MIN_10_EXP) 
- 
    MIN_EXP =
    # File 'numeric.c', line 6323The smallest possible exponent value in a double-precision floating point. Usually defaults to -1021. INT2FIX(DBL_MIN_EXP) 
- 
    NAN =
    # File 'numeric.c', line 6376An expression representing a value which is “not a number”. DBL2NUM(nan("")) 
- 
    RADIX =
    # File 'numeric.c', line 6303The base of the floating point, or number of unique digits used to represent the number. Usually defaults to 2 on most systems, which would represent a base-10 decimal. INT2FIX(FLT_RADIX) 
Instance Attribute Summary
- 
    
      #finite?  ⇒ Boolean 
    
    readonly
    Returns trueifselfis notInfinity,-Infinity, orNaN,falseotherwise:
- 
    
      #infinite?  ⇒ Boolean 
    
    readonly
    Returns: 
- 
    
      #nan?  ⇒ Boolean 
    
    readonly
    Returns trueifselfis a NaN,falseotherwise.
- 
    
      #negative?  ⇒ Boolean 
    
    readonly
    Returns trueiffloatis less than 0.
- 
    
      #positive?  ⇒ Boolean 
    
    readonly
    Returns trueiffloatis greater than 0.
- 
    
      #zero?  ⇒ Boolean 
    
    readonly
    Returns trueiffloatis 0.0.
::Numeric - Inherited
| #finite? | Returns  | 
| #infinite? | Returns  | 
| #integer? | Returns  | 
| #negative? | Returns  | 
| #nonzero? | Returns  | 
| #positive? | Returns  | 
| #real? | Returns  | 
| #zero? | Returns  | 
Instance Method Summary
- 
    
      #%(other)  ⇒ Float 
      (also: #modulo)
    
    Returns selfmodulootheras a float.
- 
    
      #*(other)  ⇒ Numeric 
    
    Returns a new Float which is the product of selfandother:
- 
    
      #**(other)  ⇒ Numeric 
    
    Raises selfto the power ofother:
- 
    
      #+(other)  ⇒ Numeric 
    
    Returns a new Float which is the sum of selfandother:
- 
    
      #-(other)  ⇒ Numeric 
    
    Returns a new Float which is the difference of selfandother:
- 
    
      #-  ⇒ Float 
    
    Returns float, negated.
- 
    
      #/(other)  ⇒ Numeric 
    
    Returns a new Float which is the result of dividing selfbyother:
- 
    
      #<(other)  ⇒ Boolean 
    
    Returns trueifselfis numerically less thanother:
- 
    
      #<=(other)  ⇒ Boolean 
    
    Returns trueifselfis numerically less than or equal toother:
- 
    
      #<=>(other)  ⇒ 1, ... 
    
    Returns a value that depends on the numeric relation between selfandother:
- #==
- #===
- 
    
      #>(other)  ⇒ Boolean 
    
    Returns trueifselfis numerically greater thanother:
- 
    
      #>=(other)  ⇒ Boolean 
    
    Returns trueifselfis numerically greater than or equal toother:
- 
    
      #abs  ⇒ Float 
    
    Returns the absolute value of float.
- 
    
      #angle  ⇒ 0, Float 
    
    Alias for #arg. 
- 
    
      #arg  ⇒ 0, Float 
      (also: #angle, #phase)
    
    Returns 0 if the value is positive, pi otherwise. 
- 
    
      #ceil(ndigits = 0)  ⇒ Float, Integer 
    
    Returns the smallest number greater than or equal to selfwith a precision ofndigitsdecimal digits.
- 
    
      #coerce(other)  ⇒ Array 
    
    Returns a 2-element array containing otherconverted to a Float andself:
- 
    
      #denominator  ⇒ Integer 
    
    Returns the denominator (always positive). 
- 
    
      #divmod(other)  ⇒ Array 
    
    Returns a 2-element array [q, r], where.
- #eql? ⇒ Boolean
- 
    
      #fdiv(other)  ⇒ Numeric 
    
    Alias for #quo. 
- 
    
      #floor(ndigits = 0)  ⇒ Float, Integer 
    
    Returns the largest number less than or equal to selfwith a precision ofndigitsdecimal digits.
- 
    
      #hash  ⇒ Integer 
    
    Returns the integer hash value for self.
- 
    
      #inspect  ⇒ String 
    
    Alias for #to_s. 
- #magnitude
- 
    
      #modulo(other)  ⇒ Float 
    
    Alias for #%. 
- 
    
      #next_float  ⇒ Float 
    
    Returns the next-larger representable Float. 
- 
    
      #numerator  ⇒ Integer 
    
    Returns the numerator. 
- 
    
      #phase  ⇒ 0, Float 
    
    Alias for #arg. 
- 
    
      #prev_float  ⇒ Float 
    
    Returns the next-smaller representable Float. 
- 
    
      #quo(other)  ⇒ Numeric 
      (also: #fdiv)
    
    Returns the quotient from dividing selfbyother:
- 
    
      #rationalize([eps])  ⇒ Rational 
    
    Returns a simpler approximation of the value (flt-|eps| <= result <= flt+|eps|). 
- 
    
      #round(ndigits = 0, half: :up])  ⇒ Integer, Float 
    
    Returns selfrounded to the nearest value with a precision ofndigitsdecimal digits.
- 
    
      #to_f  ⇒ self 
    
    Since floatis already aFloat, returnsself.
- 
    
      #to_i  ⇒ Integer 
      (also: #to_int)
    
    Returns selftruncated to an::Integer.
- 
    
      #to_int  ⇒ Integer 
    
    Alias for #to_i. 
- 
    
      #to_r  ⇒ Rational 
    
    Returns the value as a rational. 
- 
    
      #to_s  ⇒ String 
      (also: #inspect)
    
    Returns a string containing a representation of self; depending of the value ofself, the string representation may contain:
- 
    
      #truncate(ndigits = 0)  ⇒ Float, Integer 
    
    Returns selftruncated (toward zero) to a precision ofndigitsdecimal digits.
::Numeric - Inherited
| #% | Returns  | 
| #+@ | Returns  | 
| #-@ | Unary Minus—Returns the receiver, negated. | 
| #<=> | Returns zero if  | 
| #abs | Returns the absolute value of  | 
| #abs2 | Returns square of self. | 
| #angle | Alias for Numeric#arg. | 
| #arg | Returns 0 if the value is positive, pi otherwise. | 
| #ceil | Returns the smallest number that is greater than or equal to  | 
| #clone | Returns  | 
| #coerce | Returns a 2-element array containing two numeric elements, formed from the two operands  | 
| #conj | Alias for Numeric#conjugate. | 
| #conjugate | Returns self. | 
| #denominator | Returns the denominator (always positive). | 
| #div | |
| #divmod | Returns a 2-element array  | 
| #dup | Returns  | 
| #eql? | Returns  | 
| #fdiv | Returns the quotient  | 
| #floor | Returns the largest number that is less than or equal to  | 
| #i | Returns  | 
| #imag | Alias for Numeric#imaginary. | 
| #imaginary | Returns zero. | 
| #magnitude | Alias for Numeric#abs. | 
| #modulo | Alias for Numeric#%. | 
| #numerator | Returns the numerator. | 
| #phase | Alias for Numeric#arg. | 
| #polar | Returns an array; [num.abs, num.arg]. | 
| #quo | Returns the most exact division (rational for integers, float for floats). | 
| #real | Returns self. | 
| #rect | Returns an array; [num, 0]. | 
| #rectangular | Alias for Numeric#rect. | 
| #remainder | Returns the remainder after dividing  | 
| #round | Returns  | 
| #step | Generates a sequence of numbers; with a block given, traverses the sequence. | 
| #to_c | Returns the value as a complex. | 
| #to_int | Returns  | 
| #truncate | Returns  | 
| #singleton_method_added | Trap attempts to add methods to  | 
::Comparable - Included
| #< | Compares two objects based on the receiver’s #<=> method, returning true if it returns a value less than 0. | 
| #<= | Compares two objects based on the receiver’s #<=> method, returning true if it returns a value less than or equal to 0. | 
| #== | Compares two objects based on the receiver’s #<=> method, returning true if it returns 0. | 
| #> | Compares two objects based on the receiver’s #<=> method, returning true if it returns a value greater than 0. | 
| #>= | Compares two objects based on the receiver’s #<=> method, returning true if it returns a value greater than or equal to 0. | 
| #between? | |
| #clamp | 
Instance Attribute Details
    #finite?  ⇒ Boolean  (readonly)  
Returns true if self is not Infinity, -Infinity, or NaN, false otherwise:
f = 2.0      # => 2.0
f.finite?    # => true
f = 1.0/0.0  # => Infinity
f.finite?    # => false
f = -1.0/0.0 # => -Infinity
f.finite?    # => false
f = 0.0/0.0  # => NaN
f.finite?    # => false# File 'numeric.c', line 2020
VALUE
rb_flo_is_finite_p(VALUE num)
{
    double value = RFLOAT_VALUE(num);
    return RBOOL(isfinite(value));
}
  
    #infinite?  ⇒ Boolean  (readonly)  
Returns:
- 
1, if selfisInfinity.
- 
-1 if selfis-Infinity.
- 
nil, otherwise.
Examples:
f = 1.0/0.0  # => Infinity
f.infinite?  # => 1
f = -1.0/0.0 # => -Infinity
f.infinite?  # => -1
f = 1.0      # => 1.0
f.infinite?  # => nil
f = 0.0/0.0  # => NaN
f.infinite?  # => nil# File 'numeric.c', line 1990
VALUE
rb_flo_is_infinite_p(VALUE num)
{
    double value = RFLOAT_VALUE(num);
    if (isinf(value)) {
        return INT2FIX( value < 0 ? -1 : 1 );
    }
    return Qnil;
}
  
    #nan?  ⇒ Boolean  (readonly)  
Returns true if self is a NaN, false otherwise.
f = -1.0     #=> -1.0
f.nan?       #=> false
f = 0.0/0.0  #=> NaN
f.nan?       #=> true# File 'numeric.c', line 1959
static VALUE
flo_is_nan_p(VALUE num)
{
    double value = RFLOAT_VALUE(num);
    return RBOOL(isnan(value));
}
  
    #negative?  ⇒ Boolean  (readonly)  
Returns true if float is less than 0.
# File 'numeric.rb', line 400
def negative? Primitive.attr! 'inline' Primitive.cexpr! 'RBOOL(RFLOAT_VALUE(self) < 0.0)' end
    #positive?  ⇒ Boolean  (readonly)  
Returns true if float is greater than 0.
# File 'numeric.rb', line 389
def positive? Primitive.attr! 'inline' Primitive.cexpr! 'RBOOL(RFLOAT_VALUE(self) > 0.0)' end
    #zero?  ⇒ Boolean  (readonly)  
Returns true if float is 0.0.
# File 'numeric.rb', line 378
def zero? Primitive.attr! 'inline' Primitive.cexpr! 'RBOOL(FLOAT_ZERO_P(self))' end
Instance Method Details
    #%(other)  ⇒ Float     Also known as: #modulo
  
Returns self modulo other as a float.
For float f and real number r, these expressions are equivalent:
f % r
f-r*(f/r).floor
f.divmod(r)[1]See Numeric#divmod.
Examples:
10.0 % 2              # => 0.0
10.0 % 3              # => 1.0
10.0 % 4              # => 2.0
10.0 % -2             # => 0.0
10.0 % -3             # => -2.0
10.0 % -4             # => -2.0
10.0 % 4.0            # => 2.0
10.0 % Rational(4, 1) # => 2.0#modulo is an alias for %.
# File 'numeric.c', line 1414
static VALUE
flo_mod(VALUE x, VALUE y)
{
    double fy;
    if (FIXNUM_P(y)) {
        fy = (double)FIX2LONG(y);
    }
    else if (RB_BIGNUM_TYPE_P(y)) {
        fy = rb_big2dbl(y);
    }
    else if (RB_FLOAT_TYPE_P(y)) {
        fy = RFLOAT_VALUE(y);
    }
    else {
        return rb_num_coerce_bin(x, y, '%');
    }
    return DBL2NUM(ruby_float_mod(RFLOAT_VALUE(x), fy));
}
  #*(other) ⇒ Numeric
# File 'numeric.c', line 1231
VALUE
rb_float_mul(VALUE x, VALUE y)
{
    if (FIXNUM_P(y)) {
        return DBL2NUM(RFLOAT_VALUE(x) * (double)FIX2LONG(y));
    }
    else if (RB_BIGNUM_TYPE_P(y)) {
        return DBL2NUM(RFLOAT_VALUE(x) * rb_big2dbl(y));
    }
    else if (RB_FLOAT_TYPE_P(y)) {
        return DBL2NUM(RFLOAT_VALUE(x) * RFLOAT_VALUE(y));
    }
    else {
        return rb_num_coerce_bin(x, y, '*');
    }
}
  #**(other) ⇒ Numeric
# File 'numeric.c', line 1508
VALUE
rb_float_pow(VALUE x, VALUE y)
{
    double dx, dy;
    if (y == INT2FIX(2)) {
        dx = RFLOAT_VALUE(x);
        return DBL2NUM(dx * dx);
    }
    else if (FIXNUM_P(y)) {
        dx = RFLOAT_VALUE(x);
        dy = (double)FIX2LONG(y);
    }
    else if (RB_BIGNUM_TYPE_P(y)) {
        dx = RFLOAT_VALUE(x);
        dy = rb_big2dbl(y);
    }
    else if (RB_FLOAT_TYPE_P(y)) {
        dx = RFLOAT_VALUE(x);
        dy = RFLOAT_VALUE(y);
        if (dx < 0 && dy != round(dy))
            return rb_dbl_complex_new_polar_pi(pow(-dx, dy), dy);
    }
    else {
        return rb_num_coerce_bin(x, y, idPow);
    }
    return DBL2NUM(pow(dx, dy));
}
  #+(other) ⇒ Numeric
# File 'numeric.c', line 1170
VALUE
rb_float_plus(VALUE x, VALUE y)
{
    if (FIXNUM_P(y)) {
        return DBL2NUM(RFLOAT_VALUE(x) + (double)FIX2LONG(y));
    }
    else if (RB_BIGNUM_TYPE_P(y)) {
        return DBL2NUM(RFLOAT_VALUE(x) + rb_big2dbl(y));
    }
    else if (RB_FLOAT_TYPE_P(y)) {
        return DBL2NUM(RFLOAT_VALUE(x) + RFLOAT_VALUE(y));
    }
    else {
        return rb_num_coerce_bin(x, y, '+');
    }
}
  #-(other) ⇒ Numeric
# File 'numeric.c', line 1201
VALUE
rb_float_minus(VALUE x, VALUE y)
{
    if (FIXNUM_P(y)) {
        return DBL2NUM(RFLOAT_VALUE(x) - (double)FIX2LONG(y));
    }
    else if (RB_BIGNUM_TYPE_P(y)) {
        return DBL2NUM(RFLOAT_VALUE(x) - rb_big2dbl(y));
    }
    else if (RB_FLOAT_TYPE_P(y)) {
        return DBL2NUM(RFLOAT_VALUE(x) - RFLOAT_VALUE(y));
    }
    else {
        return rb_num_coerce_bin(x, y, '-');
    }
}
  
    #-  ⇒ Float   
Returns float, negated.
# File 'numeric.rb', line 367
def -@ Primitive.attr! 'inline' Primitive.cexpr! 'rb_float_uminus(self)' end
#/(other) ⇒ Numeric
# File 'numeric.c', line 1286
VALUE
rb_float_div(VALUE x, VALUE y)
{
    double num = RFLOAT_VALUE(x);
    double den;
    double ret;
    if (FIXNUM_P(y)) {
        den = FIX2LONG(y);
    }
    else if (RB_BIGNUM_TYPE_P(y)) {
        den = rb_big2dbl(y);
    }
    else if (RB_FLOAT_TYPE_P(y)) {
        den = RFLOAT_VALUE(y);
    }
    else {
        return rb_num_coerce_bin(x, y, '/');
    }
    ret = double_div_double(num, den);
    return DBL2NUM(ret);
}
  
    #<(other)  ⇒ Boolean   
Returns true if self is numerically less than other:
2.0 < 3              # => true
2.0 < 3.0            # => true
2.0 < Rational(3, 1) # => true
2.0 < 2.0            # => falseFloat::NAN < Float::NAN returns an implementation-dependent value.
# File 'numeric.c', line 1836
static VALUE
flo_lt(VALUE x, VALUE y)
{
    double a, b;
    a = RFLOAT_VALUE(x);
    if (RB_INTEGER_TYPE_P(y)) {
        VALUE rel = rb_integer_float_cmp(y, x);
        if (FIXNUM_P(rel))
            return RBOOL(-FIX2LONG(rel) < 0);
        return Qfalse;
    }
    else if (RB_FLOAT_TYPE_P(y)) {
        b = RFLOAT_VALUE(y);
#if MSC_VERSION_BEFORE(1300)
        if (isnan(b)) return Qfalse;
#endif
    }
    else {
        return rb_num_coerce_relop(x, y, '<');
    }
#if MSC_VERSION_BEFORE(1300)
    if (isnan(a)) return Qfalse;
#endif
    return RBOOL(a < b);
}
  
    #<=(other)  ⇒ Boolean   
Returns true if self is numerically less than or equal to other:
2.0 <= 3              # => true
2.0 <= 3.0            # => true
2.0 <= Rational(3, 1) # => true
2.0 <= 2.0            # => true
2.0 <= 1.0            # => falseFloat::NAN <= Float::NAN returns an implementation-dependent value.
# File 'numeric.c', line 1879
static VALUE
flo_le(VALUE x, VALUE y)
{
    double a, b;
    a = RFLOAT_VALUE(x);
    if (RB_INTEGER_TYPE_P(y)) {
        VALUE rel = rb_integer_float_cmp(y, x);
        if (FIXNUM_P(rel))
            return RBOOL(-FIX2LONG(rel) <= 0);
        return Qfalse;
    }
    else if (RB_FLOAT_TYPE_P(y)) {
        b = RFLOAT_VALUE(y);
#if MSC_VERSION_BEFORE(1300)
        if (isnan(b)) return Qfalse;
#endif
    }
    else {
        return rb_num_coerce_relop(x, y, idLE);
    }
#if MSC_VERSION_BEFORE(1300)
    if (isnan(a)) return Qfalse;
#endif
    return RBOOL(a <= b);
}
  
    #<=>(other)  ⇒ 1, ...   
Returns a value that depends on the numeric relation between self and other:
- 
-1, if selfis less thanother.
- 
0, if selfis equal toother.
- 
1, if selfis greater thanother.
- 
nil, if the two values are incommensurate.
Examples:
2.0 <=> 2              # => 0
  2.0 <=> 2.0            # => 0
  2.0 <=> Rational(2, 1) # => 0
  2.0 <=> Complex(2, 0)  # => 0
  2.0 <=> 1.9            # => 1
  2.0 <=> 2.1            # => -1
  2.0 <=> 'foo'          # => nilThis is the basis for the tests in the ::Comparable module.
Float::NAN <=> Float::NAN returns an implementation-dependent value.
# File 'numeric.c', line 1698
static VALUE
flo_cmp(VALUE x, VALUE y)
{
    double a, b;
    VALUE i;
    a = RFLOAT_VALUE(x);
    if (isnan(a)) return Qnil;
    if (RB_INTEGER_TYPE_P(y)) {
        VALUE rel = rb_integer_float_cmp(y, x);
        if (FIXNUM_P(rel))
            return LONG2FIX(-FIX2LONG(rel));
        return rel;
    }
    else if (RB_FLOAT_TYPE_P(y)) {
        b = RFLOAT_VALUE(y);
    }
    else {
        if (isinf(a) && !UNDEF_P(i = rb_check_funcall(y, rb_intern("infinite?"), 0, 0))) {
            if (RTEST(i)) {
                int j = rb_cmpint(i, x, y);
                j = (a > 0.0) ? (j > 0 ? 0 : +1) : (j < 0 ? 0 : -1);
                return INT2FIX(j);
            }
            if (a > 0.0) return INT2FIX(1);
            return INT2FIX(-1);
        }
        return rb_num_coerce_cmp(x, y, id_cmp);
    }
    return rb_dbl_cmp(a, b);
}
  #==
[ GitHub ]#===
[ GitHub ]
    #>(other)  ⇒ Boolean   
Returns true if self is numerically greater than other:
2.0 > 1              # => true
2.0 > 1.0            # => true
2.0 > Rational(1, 2) # => true
2.0 > 2.0            # => falseFloat::NAN > Float::NAN returns an implementation-dependent value.
# File 'numeric.c', line 1751
VALUE
rb_float_gt(VALUE x, VALUE y)
{
    double a, b;
    a = RFLOAT_VALUE(x);
    if (RB_INTEGER_TYPE_P(y)) {
        VALUE rel = rb_integer_float_cmp(y, x);
        if (FIXNUM_P(rel))
            return RBOOL(-FIX2LONG(rel) > 0);
        return Qfalse;
    }
    else if (RB_FLOAT_TYPE_P(y)) {
        b = RFLOAT_VALUE(y);
#if MSC_VERSION_BEFORE(1300)
        if (isnan(b)) return Qfalse;
#endif
    }
    else {
        return rb_num_coerce_relop(x, y, '>');
    }
#if MSC_VERSION_BEFORE(1300)
    if (isnan(a)) return Qfalse;
#endif
    return RBOOL(a > b);
}
  
    #>=(other)  ⇒ Boolean   
Returns true if self is numerically greater than or equal to other:
2.0 >= 1              # => true
2.0 >= 1.0            # => true
2.0 >= Rational(1, 2) # => true
2.0 >= 2.0            # => true
2.0 >= 2.1            # => falseFloat::NAN >= Float::NAN returns an implementation-dependent value.
# File 'numeric.c', line 1794
static VALUE
flo_ge(VALUE x, VALUE y)
{
    double a, b;
    a = RFLOAT_VALUE(x);
    if (RB_TYPE_P(y, T_FIXNUM) || RB_BIGNUM_TYPE_P(y)) {
        VALUE rel = rb_integer_float_cmp(y, x);
        if (FIXNUM_P(rel))
            return RBOOL(-FIX2LONG(rel) >= 0);
        return Qfalse;
    }
    else if (RB_FLOAT_TYPE_P(y)) {
        b = RFLOAT_VALUE(y);
#if MSC_VERSION_BEFORE(1300)
        if (isnan(b)) return Qfalse;
#endif
    }
    else {
        return rb_num_coerce_relop(x, y, idGE);
    }
#if MSC_VERSION_BEFORE(1300)
    if (isnan(a)) return Qfalse;
#endif
    return RBOOL(a >= b);
}
  
    
      #abs  ⇒ Float 
      #magnitude  ⇒ Float 
    
  
Float 
      #magnitude  ⇒ Float 
    Returns the absolute value of float.
(-34.56).abs   #=> 34.56
-34.56.abs     #=> 34.56
34.56.abs      #=> 34.56#magnitude is an alias for abs.
# File 'numeric.rb', line 351
def abs Primitive.attr! 'inline' Primitive.cexpr! 'rb_float_abs(self)' end
    
      #arg  ⇒ 0, Float 
      #angle  ⇒ 0, Float 
      #phase  ⇒ 0, Float 
    
  
0, Float 
      #angle  ⇒ 0, Float 
      #phase  ⇒ 0, Float 
    Alias for #arg.
    
      #arg  ⇒ 0, Float 
      #angle  ⇒ 0, Float 
      #phase  ⇒ 0, Float 
    
    Also known as: #angle, #phase
  
0, Float 
      #angle  ⇒ 0, Float 
      #phase  ⇒ 0, Float 
    Returns 0 if the value is positive, pi otherwise.
# File 'complex.c', line 2244
static VALUE
float_arg(VALUE self)
{
    if (isnan(RFLOAT_VALUE(self)))
        return self;
    if (f_tpositive_p(self))
        return INT2FIX(0);
    return rb_const_get(rb_mMath, id_PI);
}
  
    #ceil(ndigits = 0)  ⇒ Float, Integer   
Returns the smallest number greater than or equal to self with a precision of ndigits decimal digits.
When ndigits is positive, returns a float with ndigits digits after the decimal point (as available):
f = 12345.6789
f.ceil(1) # => 12345.7
f.ceil(3) # => 12345.679
f = -12345.6789
f.ceil(1) # => -12345.6
f.ceil(3) # => -12345.678When ndigits is non-positive, returns an integer with at least ndigits.abs trailing zeros:
f = 12345.6789
f.ceil(0)  # => 12346
f.ceil(-3) # => 13000
f = -12345.6789
f.ceil(0)  # => -12345
f.ceil(-3) # => -12000Note that the limited precision of floating-point arithmetic may lead to surprising results:
(2.1 / 0.7).ceil  #=> 4 (!)Related: #floor.
# File 'numeric.c', line 2245
static VALUE
flo_ceil(int argc, VALUE *argv, VALUE num)
{
    int ndigits = flo_ndigits(argc, argv);
    return rb_float_ceil(num, ndigits);
}
  #coerce(other) ⇒ Array
# File 'numeric.c', line 1144
static VALUE
flo_coerce(VALUE x, VALUE y)
{
    return rb_assoc_new(rb_Float(y), x);
}
  #denominator ⇒ Integer
Returns the denominator (always positive). The result is machine dependent.
See also #numerator.
# File 'rational.c', line 2094
VALUE
rb_float_denominator(VALUE self)
{
    double d = RFLOAT_VALUE(self);
    VALUE r;
    if (!isfinite(d))
        return INT2FIX(1);
    r = float_to_r(self);
    return nurat_denominator(r);
}
  #divmod(other) ⇒ Array
Returns a 2-element array [q, r], where
q = (self/other).floor      # Quotient
r = self % other            # RemainderExamples:
11.0.divmod(4)              # => [2, 3.0]
11.0.divmod(-4)             # => [-3, -1.0]
-11.0.divmod(4)             # => [-3, 1.0]
-11.0.divmod(-4)            # => [2, -3.0]
12.0.divmod(4)              # => [3, 0.0]
12.0.divmod(-4)             # => [-3, 0.0]
-12.0.divmod(4)             # => [-3, -0.0]
-12.0.divmod(-4)            # => [3, -0.0]
13.0.divmod(4.0)            # => [3, 1.0]
13.0.divmod(Rational(4, 1)) # => [3, 1.0]# File 'numeric.c', line 1469
static VALUE
flo_divmod(VALUE x, VALUE y)
{
    double fy, div, mod;
    volatile VALUE a, b;
    if (FIXNUM_P(y)) {
        fy = (double)FIX2LONG(y);
    }
    else if (RB_BIGNUM_TYPE_P(y)) {
        fy = rb_big2dbl(y);
    }
    else if (RB_FLOAT_TYPE_P(y)) {
        fy = RFLOAT_VALUE(y);
    }
    else {
        return rb_num_coerce_bin(x, y, id_divmod);
    }
    flodivmod(RFLOAT_VALUE(x), fy, &div, &mod);
    a = dbl2ival(div);
    b = DBL2NUM(mod);
    return rb_assoc_new(a, b);
}
  
    #eql?  ⇒ Boolean 
  
Alias for #quo.
    #floor(ndigits = 0)  ⇒ Float, Integer   
Returns the largest number less than or equal to self with a precision of ndigits decimal digits.
When ndigits is positive, returns a float with ndigits digits after the decimal point (as available):
f = 12345.6789
f.floor(1) # => 12345.6
f.floor(3) # => 12345.678
f = -12345.6789
f.floor(1) # => -12345.7
f.floor(3) # => -12345.679When ndigits is non-positive, returns an integer with at least ndigits.abs trailing zeros:
f = 12345.6789
f.floor(0)  # => 12345
f.floor(-3) # => 12000
f = -12345.6789
f.floor(0)  # => -12346
f.floor(-3) # => -13000Note that the limited precision of floating-point arithmetic may lead to surprising results:
(0.3 / 0.1).floor  #=> 2 (!)Related: #ceil.
# File 'numeric.c', line 2202
static VALUE
flo_floor(int argc, VALUE *argv, VALUE num)
{
    int ndigits = flo_ndigits(argc, argv);
    return rb_float_floor(num, ndigits);
}
  #hash ⇒ Integer
Returns the integer hash value for self.
See also Object#hash.
# File 'numeric.c', line 1648
static VALUE
flo_hash(VALUE num)
{
    return rb_dbl_hash(RFLOAT_VALUE(num));
}
  Alias for #to_s.
#magnitude
[ GitHub ]# File 'numeric.rb', line 356
def magnitude Primitive.attr! 'inline' Primitive.cexpr! 'rb_float_abs(self)' end
    
      #%(other)  ⇒ Float 
      #modulo(other)  ⇒ Float 
    
  
Float 
      #modulo(other)  ⇒ Float 
    Alias for #%.
    #next_float  ⇒ Float   
Returns the next-larger representable Float.
These examples show the internally stored values (64-bit hexadecimal) for each Float f and for the corresponding f.next_float:
f = 0.0      # 0x0000000000000000
f.next_float # 0x0000000000000001
f = 0.01     # 0x3f847ae147ae147b
f.next_float # 0x3f847ae147ae147cIn the remaining examples here, the output is shown in the usual way (result #to_s):
0.01.next_float    # => 0.010000000000000002
1.0.next_float     # => 1.0000000000000002
100.0.next_float   # => 100.00000000000001
f = 0.01
(0..3).each_with_index {|i| printf "%2d %-20a %s\n", i, f, f.to_s; f = f.next_float }Output:
 0 0x1ae147ae147bp-7 0.01
 1 0x1ae147ae147cp-7 0.010000000000000002
 2 0x1ae147ae147dp-7 0.010000000000000004
 3 0x1ae147ae147ep-7 0.010000000000000005
f = 0.0; 100.times { f += 0.1 }
f                           # => 9.99999999999998       # should be 10.0 in the ideal world.
10-f                        # => 1.9539925233402755e-14 # the floating point error.
10.0.next_float-10          # => 1.7763568394002505e-15 # 1 ulp (unit in the last place).
(10-f)/(10.0.next_float-10) # => 11.0                   # the error is 11 ulp.
(10-f)/(10*Float::EPSILON)  # => 8.8                    # approximation of the above.
"%a" % 10                   # => "0x1.4p+3"
"%a" % f                    # => "0x1.3fffffffffff5p+3" # the last hex digit is 5.  16 - 5 = 11 ulp.Related: #prev_float
# File 'numeric.c', line 2081
static VALUE
flo_next_float(VALUE vx)
{
    return flo_nextafter(vx, HUGE_VAL);
}
  #numerator ⇒ Integer
Returns the numerator. The result is machine dependent.
n = 0.3.numerator    #=> 5404319552844595
d = 0.3.denominator  #=> 18014398509481984
n.fdiv(d)            #=> 0.3See also #denominator.
# File 'rational.c', line 2074
VALUE
rb_float_numerator(VALUE self)
{
    double d = RFLOAT_VALUE(self);
    VALUE r;
    if (!isfinite(d))
        return self;
    r = float_to_r(self);
    return nurat_numerator(r);
}
  
    
      #arg  ⇒ 0, Float 
      #angle  ⇒ 0, Float 
      #phase  ⇒ 0, Float 
    
  
0, Float 
      #angle  ⇒ 0, Float 
      #phase  ⇒ 0, Float 
    Alias for #arg.
    #prev_float  ⇒ Float   
Returns the next-smaller representable Float.
These examples show the internally stored values (64-bit hexadecimal) for each Float f and for the corresponding f.pev_float:
f = 5e-324   # 0x0000000000000001
f.prev_float # 0x0000000000000000
f = 0.01     # 0x3f847ae147ae147b
f.prev_float # 0x3f847ae147ae147aIn the remaining examples here, the output is shown in the usual way (result #to_s):
0.01.prev_float   # => 0.009999999999999998
1.0.prev_float    # => 0.9999999999999999
100.0.prev_float  # => 99.99999999999999
f = 0.01
(0..3).each_with_index {|i| printf "%2d %-20a %s\n", i, f, f.to_s; f = f.prev_float }Output:
0 0x1ae147ae147bp-7 0.01
1 0x1ae147ae147ap-7 0.009999999999999998
2 0x1ae147ae1479p-7 0.009999999999999997
3 0x1ae147ae1478p-7 0.009999999999999995Related: #next_float.
# File 'numeric.c', line 2122
static VALUE
flo_prev_float(VALUE vx)
{
    return flo_nextafter(vx, -HUGE_VAL);
}
  #quo(other) ⇒ Numeric Also known as: #fdiv
# File 'numeric.c', line 1326
static VALUE
flo_quo(VALUE x, VALUE y)
{
    return num_funcall1(x, '/', y);
}
  #rationalize([eps]) ⇒ Rational
Returns a simpler approximation of the value (flt-|eps| <= result <= flt+|eps|).  If the optional argument eps is not given, it will be chosen automatically.
0.3.rationalize          #=> (3/10)
1.333.rationalize        #=> (1333/1000)
1.333.rationalize(0.01)  #=> (4/3)See also #to_r.
# File 'rational.c', line 2276
static VALUE
float_rationalize(int argc, VALUE *argv, VALUE self)
{
    double d = RFLOAT_VALUE(self);
    VALUE rat;
    int neg = d < 0.0;
    if (neg) self = DBL2NUM(-d);
    if (rb_check_arity(argc, 0, 1)) {
        rat = rb_flt_rationalize_with_prec(self, argv[0]);
    }
    else {
        rat = rb_flt_rationalize(self);
    }
    if (neg) RATIONAL_SET_NUM(rat, rb_int_uminus(RRATIONAL(rat)->num));
    return rat;
}
  
    #round(ndigits = 0, half: :up])  ⇒ Integer, Float   
Returns self rounded to the nearest value with a precision of ndigits decimal digits.
When ndigits is non-negative, returns a float with ndigits after the decimal point (as available):
f = 12345.6789
f.round(1) # => 12345.7
f.round(3) # => 12345.679
f = -12345.6789
f.round(1) # => -12345.7
f.round(3) # => -12345.679When ndigits is negative, returns an integer with at least ndigits.abs trailing zeros:
f = 12345.6789
f.round(0)  # => 12346
f.round(-3) # => 12000
f = -12345.6789
f.round(0)  # => -12346
f.round(-3) # => -12000If keyword argument half is given, and self is equidistant from the two candidate values, the rounding is according to the given half value:
- 
:upornil: round away from zero:2.5.round(half: :up) # => 3 3.5.round(half: :up) # => 4 (-2.5).round(half: :up) # => -3
- 
:down: round toward zero:2.5.round(half: :down) # => 2 3.5.round(half: :down) # => 3 (-2.5).round(half: :down) # => -2
- 
:even: round toward the candidate whose last nonzero digit is even:2.5.round(half: :even) # => 2 3.5.round(half: :even) # => 4 (-2.5).round(half: :even) # => -2
Raises and exception if the value for half is invalid.
Related: #truncate.
# File 'numeric.c', line 2503
static VALUE
flo_round(int argc, VALUE *argv, VALUE num)
{
    double number, f, x;
    VALUE nd, opt;
    int ndigits = 0;
    enum ruby_num_rounding_mode mode;
    if (rb_scan_args(argc, argv, "01:", &nd, &opt)) {
        ndigits = NUM2INT(nd);
    }
    mode = rb_num_get_rounding_option(opt);
    number = RFLOAT_VALUE(num);
    if (number == 0.0) {
        return ndigits > 0 ? DBL2NUM(number) : INT2FIX(0);
    }
    if (ndigits < 0) {
        return rb_int_round(flo_to_i(num), ndigits, mode);
    }
    if (ndigits == 0) {
        x = ROUND_CALL(mode, round, (number, 1.0));
        return dbl2ival(x);
    }
    if (isfinite(number)) {
        int binexp;
        frexp(number, &binexp);
        if (float_round_overflow(ndigits, binexp)) return num;
        if (float_round_underflow(ndigits, binexp)) return DBL2NUM(0);
        if (ndigits > 14) {
            /* In this case, pow(10, ndigits) may not be accurate. */
            return rb_flo_round_by_rational(argc, argv, num);
        }
        f = pow(10, ndigits);
        x = ROUND_CALL(mode, round, (number, f));
        return DBL2NUM(x / f);
    }
    return num;
}
  
    #to_f  ⇒ self   
Since float is already a Float, returns self.
# File 'numeric.rb', line 334
def to_f self end
#to_i ⇒ Integer Also known as: #to_int
# File 'numeric.c', line 2596
static VALUE
flo_to_i(VALUE num)
{
    double f = RFLOAT_VALUE(num);
    if (f > 0.0) f = floor(f);
    if (f < 0.0) f = ceil(f);
    return dbl2ival(f);
}
  Alias for #to_i.
#to_r ⇒ Rational
Returns the value as a rational.
2.0.to_r    #=> (2/1)
2.5.to_r    #=> (5/2)
-0.75.to_r  #=> (-3/4)
0.0.to_r    #=> (0/1)
0.3.to_r    #=> (5404319552844595/18014398509481984)NOTE: 0.3.to_r isn’t the same as “0.3”.to_r. The latter is equivalent to “3/10”.to_r, but the former isn’t so.
0.3.to_r   == 3/10r  #=> false
"0.3".to_r == 3/10r  #=> trueSee also #rationalize.
# File 'rational.c', line 2191
static VALUE
float_to_r(VALUE self)
{
    VALUE f;
    int n;
    float_decode_internal(self, &f, &n);
#if FLT_RADIX == 2
    if (n == 0)
        return rb_rational_new1(f);
    if (n > 0)
        return rb_rational_new1(rb_int_lshift(f, INT2FIX(n)));
    n = -n;
    return rb_rational_new2(f, rb_int_lshift(ONE, INT2FIX(n)));
#else
    f = rb_int_mul(f, rb_int_pow(INT2FIX(FLT_RADIX), n));
    if (RB_TYPE_P(f, T_RATIONAL))
        return f;
    return rb_rational_new1(f);
#endif
}
  #to_s ⇒ String Also known as: #inspect
Returns a string containing a representation of self; depending of the value of self, the string representation may contain:
- 
A fixed-point number. 
- 
A number in “scientific notation” (containing an exponent). 
- 
‘Infinity’. 
- 
‘-Infinity’. 
- 
‘NaN’ (indicating not-a-number). 3.14.to_s # => “3.14” (10.1**50).to_s # => “1.644631821843879e+50” (10.1**500).to_s # => “Infinity” (-10.1**500).to_s # => “-Infinity” (0.0/0.0).to_s # => “NaN” 
# File 'numeric.c', line 1053
static VALUE
flo_to_s(VALUE flt)
{
    enum {decimal_mant = DBL_MANT_DIG-DBL_DIG};
    enum {float_dig = DBL_DIG+1};
    char buf[float_dig + roomof(decimal_mant, CHAR_BIT) + 10];
    double value = RFLOAT_VALUE(flt);
    VALUE s;
    char *p, *e;
    int sign, decpt, digs;
    if (isinf(value)) {
        static const char minf[] = "-Infinity";
        const int pos = (value > 0); /* skip "-" */
        return rb_usascii_str_new(minf+pos, strlen(minf)-pos);
    }
    else if (isnan(value))
        return rb_usascii_str_new2("NaN");
    p = ruby_dtoa(value, 0, 0, &decpt, &sign, &e);
    s = sign ? rb_usascii_str_new_cstr("-") : rb_usascii_str_new(0, 0);
    if ((digs = (int)(e - p)) >= (int)sizeof(buf)) digs = (int)sizeof(buf) - 1;
    memcpy(buf, p, digs);
    xfree(p);
    if (decpt > 0) {
        if (decpt < digs) {
            memmove(buf + decpt + 1, buf + decpt, digs - decpt);
            buf[decpt] = '.';
            rb_str_cat(s, buf, digs + 1);
        }
        else if (decpt <= DBL_DIG) {
            long len;
            char *ptr;
            rb_str_cat(s, buf, digs);
            rb_str_resize(s, (len = RSTRING_LEN(s)) + decpt - digs + 2);
            ptr = RSTRING_PTR(s) + len;
            if (decpt > digs) {
                memset(ptr, '0', decpt - digs);
                ptr += decpt - digs;
            }
            memcpy(ptr, ".0", 2);
        }
        else {
            goto exp;
        }
    }
    else if (decpt > -4) {
        long len;
        char *ptr;
        rb_str_cat(s, "0.", 2);
        rb_str_resize(s, (len = RSTRING_LEN(s)) - decpt + digs);
        ptr = RSTRING_PTR(s);
        memset(ptr += len, '0', -decpt);
        memcpy(ptr -= decpt, buf, digs);
    }
    else {
        goto exp;
    }
    return s;
  exp:
    if (digs > 1) {
        memmove(buf + 2, buf + 1, digs - 1);
    }
    else {
        buf[2] = '0';
        digs++;
    }
    buf[1] = '.';
    rb_str_cat(s, buf, digs + 1);
    rb_str_catf(s, "e%+03d", decpt - 1);
    return s;
}
  
    #truncate(ndigits = 0)  ⇒ Float, Integer   
Returns self truncated (toward zero) to a precision of ndigits decimal digits.
When ndigits is positive, returns a float with ndigits digits after the decimal point (as available):
f = 12345.6789
f.truncate(1) # => 12345.6
f.truncate(3) # => 12345.678
f = -12345.6789
f.truncate(1) # => -12345.6
f.truncate(3) # => -12345.678When ndigits is negative, returns an integer with at least ndigits.abs trailing zeros:
f = 12345.6789
f.truncate(0)  # => 12345
f.truncate(-3) # => 12000
f = -12345.6789
f.truncate(0)  # => -12345
f.truncate(-3) # => -12000Note that the limited precision of floating-point arithmetic may lead to surprising results:
(0.3 / 0.1).truncate  #=> 2 (!)Related: #round.
# File 'numeric.c', line 2642
static VALUE
flo_truncate(int argc, VALUE *argv, VALUE num)
{
    if (signbit(RFLOAT_VALUE(num)))
        return flo_ceil(argc, argv, num);
    else
        return flo_floor(argc, argv, num);
}