Class: Numeric

Inherits:
Object show all
Includes:
Comparable
Defined in:
numeric.c

Direct Known Subclasses

Float, Integer

Instance Method Summary (collapse)

Methods included from Comparable

#<, #<=, #==, #>, #>=, #between?

Instance Method Details

- (Numeric) +

Unary Plus---Returns the receiver's value.



# File 'numeric.c'

/*
 *  call-seq:
 *     +num    => num
 *
 *  Unary Plus---Returns the receiver's value.
 */

static VALUE
num_uplus(num)
    VALUE num;
{
    return num;
}

- (Numeric) -

Unary Minus---Returns the receiver's value, negated.



# File 'numeric.c'

/*
 *  call-seq:
 *     -num    => numeric
 *
 *  Unary Minus---Returns the receiver's value, negated.
 */

static VALUE
num_uminus(num)
    VALUE num;
{
    VALUE zero;

    zero = INT2FIX(0);
    do_coerce(&zero, &num, Qtrue);

    return rb_funcall(zero, '-', 1, num);
}

- (0?) <=>(other)

Returns zero if num equals other, nil otherwise.



# File 'numeric.c'

/*
 *  call-seq:
 *     num <=> other -> 0 or nil
 *
 *  Returns zero if <i>num</i> equals <i>other</i>, <code>nil</code>
 *  otherwise.
 */

static VALUE
num_cmp(x, y)
    VALUE x, y;
{
    if (x == y) return INT2FIX(0);
    return Qnil;
}

- (Numeric) abs

Returns the absolute value of num.

12.abs         #=> 12
(-34.56).abs   #=> 34.56
-34.56.abs     #=> 34.56


# File 'numeric.c'

/*
 *  call-seq:
 *     num.abs   => num or numeric
 *
 *  Returns the absolute value of <i>num</i>.
 *
 *     12.abs         #=> 12
 *     (-34.56).abs   #=> 34.56
 *     -34.56.abs     #=> 34.56
 */

static VALUE
num_abs(num)
    VALUE num;
{
    if (RTEST(rb_funcall(num, '<', 1, INT2FIX(0)))) {
    return rb_funcall(num, rb_intern("-@"), 0);
    }
    return num;
}

- (Integer) ceil

Returns the smallest Integer greater than or equal to num. Class Numeric achieves this by converting itself to a Float then invoking Float#ceil.

1.ceil        #=> 1
1.2.ceil      #=> 2
(-1.2).ceil   #=> -1
(-1.0).ceil   #=> -1


# File 'numeric.c'

/*
 *  call-seq:
 *     num.ceil    => integer
 *
 *  Returns the smallest <code>Integer</code> greater than or equal to
 *  <i>num</i>. Class <code>Numeric</code> achieves this by converting
 *  itself to a <code>Float</code> then invoking
 *  <code>Float#ceil</code>.
 *
 *     1.ceil        #=> 1
 *     1.2.ceil      #=> 2
 *     (-1.2).ceil   #=> -1
 *     (-1.0).ceil   #=> -1
 */

static VALUE
num_ceil(num)
    VALUE num;
{
    return flo_ceil(rb_Float(num));
}

- (Array) coerce(numeric)

If aNumeric is the same type as num, returns an array containing aNumeric and num. Otherwise, returns an array with both aNumeric and num represented as Float objects. This coercion mechanism is used by Ruby to handle mixed-type numeric operations: it is intended to find a compatible common type between the two operands of the operator.

1.coerce(2.5)   #=> [2.5, 1.0]
1.2.coerce(3)   #=> [3.0, 1.2]
1.coerce(2)     #=> [2, 1]


# File 'numeric.c'

/*
 *  call-seq:
 *     num.coerce(numeric)   => array
 *
 *  If <i>aNumeric</i> is the same type as <i>num</i>, returns an array
 *  containing <i>aNumeric</i> and <i>num</i>. Otherwise, returns an
 *  array with both <i>aNumeric</i> and <i>num</i> represented as
 *  <code>Float</code> objects. This coercion mechanism is used by
 *  Ruby to handle mixed-type numeric operations: it is intended to
 *  find a compatible common type between the two operands of the operator.
 *
 *     1.coerce(2.5)   #=> [2.5, 1.0]
 *     1.2.coerce(3)   #=> [3.0, 1.2]
 *     1.coerce(2)     #=> [2, 1]
 */

static VALUE
num_coerce(x, y)
    VALUE x, y;
{
    if (CLASS_OF(x) == CLASS_OF(y))
    return rb_assoc_new(y, x);
    x = rb_Float(x);
    y = rb_Float(y);
    return rb_assoc_new(y, x);
}

- (Integer) div(numeric)

Uses / to perform division, then converts the result to an integer. Numeric does not define the / operator; this is left to subclasses.



# File 'numeric.c'

/*
 *  call-seq:
 *     num.div(numeric)    => integer
 *
 *  Uses <code>/</code> to perform division, then converts the result to
 *  an integer. <code>Numeric</code> does not define the <code>/</code>
 *  operator; this is left to subclasses.
 */

static VALUE
num_div(x, y)
    VALUE x, y;
{
    return num_floor(rb_funcall(x, '/', 1, y));
}

- (Array) divmod(aNumeric)

Returns an array containing the quotient and modulus obtained by dividing num by aNumeric. If q, r = x.divmod(y), then

q = floor(float(x)/float(y))
x = q*y + r

The quotient is rounded toward -infinity, as shown in the following table:

 a    |  b  |  a.divmod(b)  |   a/b   | a.modulo(b) | a.remainder(b)
------+-----+---------------+---------+-------------+---------------
 13   |  4  |   3,    1     |   3     |    1        |     1
------+-----+---------------+---------+-------------+---------------
 13   | -4  |  -4,   -3     |  -3     |   -3        |     1
------+-----+---------------+---------+-------------+---------------
-13   |  4  |  -4,    3     |  -4     |    3        |    -1
------+-----+---------------+---------+-------------+---------------
-13   | -4  |   3,   -1     |   3     |   -1        |    -1
------+-----+---------------+---------+-------------+---------------
 11.5 |  4  |   2,    3.5   |   2.875 |    3.5      |     3.5
------+-----+---------------+---------+-------------+---------------
 11.5 | -4  |  -3,   -0.5   |  -2.875 |   -0.5      |     3.5
------+-----+---------------+---------+-------------+---------------
-11.5 |  4  |  -3,    0.5   |  -2.875 |    0.5      |    -3.5
------+-----+---------------+---------+-------------+---------------
-11.5 | -4  |   2    -3.5   |   2.875 |   -3.5      |    -3.5

Examples

11.divmod(3)         #=> [3, 2]
11.divmod(-3)        #=> [-4, -1]
11.divmod(3.5)       #=> [3, 0.5]
(-11).divmod(3.5)    #=> [-4, 3.0]
(11.5).divmod(3.5)   #=> [3, 1.0]


# File 'numeric.c'

/*
 *  call-seq:
 *     num.divmod( aNumeric ) -> anArray
 *
 *  Returns an array containing the quotient and modulus obtained by
 *  dividing <i>num</i> by <i>aNumeric</i>. If <code>q, r =
 *  x.divmod(y)</code>, then
 *
 *      q = floor(float(x)/float(y))
 *      x = q*y + r
 *
 *  The quotient is rounded toward -infinity, as shown in the following table:
 *
 *     a    |  b  |  a.divmod(b)  |   a/b   | a.modulo(b) | a.remainder(b)
 *    ------+-----+---------------+---------+-------------+---------------
 *     13   |  4  |   3,    1     |   3     |    1        |     1
 *    ------+-----+---------------+---------+-------------+---------------
 *     13   | -4  |  -4,   -3     |  -3     |   -3        |     1
 *    ------+-----+---------------+---------+-------------+---------------
 *    -13   |  4  |  -4,    3     |  -4     |    3        |    -1
 *    ------+-----+---------------+---------+-------------+---------------
 *    -13   | -4  |   3,   -1     |   3     |   -1        |    -1
 *    ------+-----+---------------+---------+-------------+---------------
 *     11.5 |  4  |   2,    3.5   |   2.875 |    3.5      |     3.5
 *    ------+-----+---------------+---------+-------------+---------------
 *     11.5 | -4  |  -3,   -0.5   |  -2.875 |   -0.5      |     3.5
 *    ------+-----+---------------+---------+-------------+---------------
 *    -11.5 |  4  |  -3,    0.5   |  -2.875 |    0.5      |    -3.5
 *    ------+-----+---------------+---------+-------------+---------------
 *    -11.5 | -4  |   2    -3.5   |   2.875 |   -3.5      |    -3.5
 *
 *
 *  Examples
 *     11.divmod(3)         #=> [3, 2]
 *     11.divmod(-3)        #=> [-4, -1]
 *     11.divmod(3.5)       #=> [3, 0.5]
 *     (-11).divmod(3.5)    #=> [-4, 3.0]
 *     (11.5).divmod(3.5)   #=> [3, 1.0]
 */

static VALUE
num_divmod(x, y)
    VALUE x, y;
{
    return rb_assoc_new(num_div(x, y), rb_funcall(x, '%', 1, y));
}

- (Boolean) eql?(numeric)

Returns true if num and numeric are the same type and have equal values.

1 == 1.0          #=> true
1.eql?(1.0)       #=> false
(1.0).eql?(1.0)   #=> true


# File 'numeric.c'

/*
 *  call-seq:
 *     num.eql?(numeric)    => true or false
 *
 *  Returns <code>true</code> if <i>num</i> and <i>numeric</i> are the
 *  same type and have equal values.
 *
 *     1 == 1.0          #=> true
 *     1.eql?(1.0)       #=> false
 *     (1.0).eql?(1.0)   #=> true
 */

static VALUE
num_eql(x, y)
    VALUE x, y;
{
    if (TYPE(x) != TYPE(y)) return Qfalse;

    return rb_equal(x, y);
}

- (Object) quo(numeric) - (Object) fdiv(numeric)

Equivalent to Numeric#/, but overridden in subclasses.



# File 'numeric.c'

/*
 *  call-seq:
 *     num.quo(numeric)    =>   result
 *     num.fdiv(numeric)   =>   result
 *
 *  Equivalent to <code>Numeric#/</code>, but overridden in subclasses.
 */

static VALUE
num_quo(x, y)
    VALUE x, y;
{
    return rb_funcall(x, '/', 1, y);
}

- (Integer) floor

Returns the largest integer less than or equal to num. Numeric implements this by converting anInteger to a Float and invoking Float#floor.

1.floor      #=> 1
(-1).floor   #=> -1


# File 'numeric.c'

/*
 *  call-seq:
 *     num.floor    => integer
 *
 *  Returns the largest integer less than or equal to <i>num</i>.
 *  <code>Numeric</code> implements this by converting <i>anInteger</i>
 *  to a <code>Float</code> and invoking <code>Float#floor</code>.
 *
 *     1.floor      #=> 1
 *     (-1).floor   #=> -1
 */

static VALUE
num_floor(num)
    VALUE num;
{
    return flo_floor(rb_Float(num));
}

- (Object) initialize_copy

:nodoc:



# File 'numeric.c'

/* :nodoc: */
static VALUE
num_init_copy(x, y)
    VALUE x, y;
{
    /* Numerics are immutable values, which should not be copied */
    rb_raise(rb_eTypeError, "can't copy %s", rb_obj_classname(x));
    return Qnil;        /* not reached */
}

- (Boolean) integer?

Returns true if num is an Integer (including Fixnum and Bignum).



# File 'numeric.c'

/*
 *  call-seq:
 *     num.integer? -> true or false
 *
 *  Returns <code>true</code> if <i>num</i> is an <code>Integer</code>
 *  (including <code>Fixnum</code> and <code>Bignum</code>).
 */

static VALUE
num_int_p(num)
    VALUE num;
{
    return Qfalse;
}

- (Object) modulo(numeric)

Equivalent to num.divmod(aNumeric).



# File 'numeric.c'

/*
 *  call-seq:
 *     num.modulo(numeric)    => result
 *
 *  Equivalent to
 *  <i>num</i>.<code>divmod(</code><i>aNumeric</i><code>)[1]</code>.
 */

static VALUE
num_modulo(x, y)
    VALUE x, y;
{
    return rb_funcall(x, '%', 1, y);
}

- (Numeric?) nonzero?

Returns num if num is not zero, nil otherwise. This behavior is useful when chaining comparisons:

a = %w( z Bb bB bb BB a aA Aa AA A )
b = a.sort {|a,b| (a.downcase <=> b.downcase).nonzero? || a <=> b }
b   #=> ["A", "a", "AA", "Aa", "aA", "BB", "Bb", "bB", "bb", "z"]


# File 'numeric.c'

/*
 *  call-seq:
 *     num.nonzero?    => num or nil
 *
 *  Returns <i>num</i> if <i>num</i> is not zero, <code>nil</code>
 *  otherwise. This behavior is useful when chaining comparisons:
 *
 *     a = %w( z Bb bB bb BB a aA Aa AA A )
 *     b = a.sort {|a,b| (a.downcase <=> b.downcase).nonzero? || a <=> b }
 *     b   #=> ["A", "a", "AA", "Aa", "aA", "BB", "Bb", "bB", "bb", "z"]
 */

static VALUE
num_nonzero_p(num)
    VALUE num;
{
    if (RTEST(rb_funcall(num, rb_intern("zero?"), 0, 0))) {
    return Qnil;
    }
    return num;
}

- (Object) quo(numeric) - (Object) fdiv(numeric)

Equivalent to Numeric#/, but overridden in subclasses.



# File 'numeric.c'

/*
 *  call-seq:
 *     num.quo(numeric)    =>   result
 *     num.fdiv(numeric)   =>   result
 *
 *  Equivalent to <code>Numeric#/</code>, but overridden in subclasses.
 */

static VALUE
num_quo(x, y)
    VALUE x, y;
{
    return rb_funcall(x, '/', 1, y);
}

- (Object) remainder(numeric)

If num and numeric have different signs, returns mod-numeric; otherwise, returns mod. In both cases mod is the value num.modulo(numeric). The differences between remainder and modulo (%) are shown in the table under Numeric#divmod.



# File 'numeric.c'

/*
 *  call-seq:
 *     num.remainder(numeric)    => result
 *
 *  If <i>num</i> and <i>numeric</i> have different signs, returns
 *  <em>mod</em>-<i>numeric</i>; otherwise, returns <em>mod</em>. In
 *  both cases <em>mod</em> is the value
 *  <i>num</i>.<code>modulo(</code><i>numeric</i><code>)</code>. The
 *  differences between <code>remainder</code> and modulo
 *  (<code>%</code>) are shown in the table under <code>Numeric#divmod</code>.
 */

static VALUE
num_remainder(x, y)
    VALUE x, y;
{
    VALUE z = rb_funcall(x, '%', 1, y);

    if ((!rb_equal(z, INT2FIX(0))) &&
    ((RTEST(rb_funcall(x, '<', 1, INT2FIX(0))) &&
      RTEST(rb_funcall(y, '>', 1, INT2FIX(0)))) ||
     (RTEST(rb_funcall(x, '>', 1, INT2FIX(0))) &&
      RTEST(rb_funcall(y, '<', 1, INT2FIX(0)))))) {
    return rb_funcall(z, '-', 1, y);
    }
    return z;
}

- (Integer) round

Rounds num to the nearest integer. Numeric implements this by converting itself to a Float and invoking Float#round.



# File 'numeric.c'

/*
 *  call-seq:
 *     num.round    => integer
 *
 *  Rounds <i>num</i> to the nearest integer. <code>Numeric</code>
 *  implements this by converting itself to a
 *  <code>Float</code> and invoking <code>Float#round</code>.
 */

static VALUE
num_round(num)
    VALUE num;
{
    return flo_round(rb_Float(num));
}

- (Object) singleton_method_added

Trap attempts to add methods to Numeric objects. Always raises a TypeError



# File 'numeric.c'

/*
 * Trap attempts to add methods to <code>Numeric</code> objects. Always
 * raises a <code>TypeError</code>
 */

static VALUE
num_sadded(x, name)
    VALUE x, name;
{
    ruby_frame = ruby_frame->prev; /* pop frame for "singleton_method_added" */
    /* Numerics should be values; singleton_methods should not be added to them */
    rb_raise(rb_eTypeError,
         "can't define singleton method \"%s\" for %s",
         rb_id2name(rb_to_id(name)),
         rb_obj_classname(x));
    return Qnil;        /* not reached */
}

- (Numeric) step(limit, step) {|i| ... }

Invokes block with the sequence of numbers starting at num, incremented by step on each call. The loop finishes when the value to be passed to the block is greater than limit (if step is positive) or less than limit (if step is negative). If all the arguments are integers, the loop operates using an integer counter. If any of the arguments are floating point numbers, all are converted to floats, and the loop is executed floor(n + n*epsilon)+ 1 times, where n = (limit - num)/step. Otherwise, the loop starts at num, uses either the < or > operator to compare the counter against limit, and increments itself using the + operator.

1.step(10, 2) { |i| print i, " " }
Math::E.step(Math::PI, 0.2) { |f| print f, " " }

produces:

1 3 5 7 9
2.71828182845905 2.91828182845905 3.11828182845905

Yields:

  • (i)


# File 'numeric.c'

/*
 *  call-seq:
 *     num.step(limit, step ) {|i| block }     => num
 *
 *  Invokes <em>block</em> with the sequence of numbers starting at
 *  <i>num</i>, incremented by <i>step</i> on each call. The loop
 *  finishes when the value to be passed to the block is greater than
 *  <i>limit</i> (if <i>step</i> is positive) or less than
 *  <i>limit</i> (if <i>step</i> is negative). If all the arguments are
 *  integers, the loop operates using an integer counter. If any of the
 *  arguments are floating point numbers, all are converted to floats,
 *  and the loop is executed <i>floor(n + n*epsilon)+ 1</i> times,
 *  where <i>n = (limit - num)/step</i>. Otherwise, the loop
 *  starts at <i>num</i>, uses either the <code><</code> or
 *  <code>></code> operator to compare the counter against
 *  <i>limit</i>, and increments itself using the <code>+</code>
 *  operator.
 *
 *     1.step(10, 2) { |i| print i, " " }
 *     Math::E.step(Math::PI, 0.2) { |f| print f, " " }
 *
 *  <em>produces:</em>
 *
 *     1 3 5 7 9
 *     2.71828182845905 2.91828182845905 3.11828182845905
 */

static VALUE
num_step(argc, argv, from)
    int argc;
    VALUE *argv;
    VALUE from;
{
    VALUE to, step;

    RETURN_ENUMERATOR(from, argc, argv);

    if (argc == 1) {
    to = argv[0];
    step = INT2FIX(1);
    }
    else {
    if (argc == 2) {
        to = argv[0];
        step = argv[1];
    }
    else {
        rb_raise(rb_eArgError, "wrong number of arguments");
    }
    if (rb_equal(step, INT2FIX(0))) {
        rb_raise(rb_eArgError, "step can't be 0");
    }
    }

    if (FIXNUM_P(from) && FIXNUM_P(to) && FIXNUM_P(step)) {
    long i, end, diff;

    i = FIX2LONG(from);
    end = FIX2LONG(to);
    diff = FIX2LONG(step);

    if (diff > 0) {
        while (i <= end) {
        rb_yield(LONG2FIX(i));
        i += diff;
        }
    }
    else {
        while (i >= end) {
        rb_yield(LONG2FIX(i));
        i += diff;
        }
    }
    }
    else if (!ruby_float_step(from, to, step, Qfalse)) {
    VALUE i = from;
    ID cmp;

    if (RTEST(rb_funcall(step, '>', 1, INT2FIX(0)))) {
        cmp = '>';
    }
    else {
        cmp = '<';
    }
    for (;;) {
        if (RTEST(rb_funcall(i, cmp, 1, to))) break;
        rb_yield(i);
        i = rb_funcall(i, '+', 1, step);
    }
    }
    return from;
}

- (Integer) to_int

Invokes the child class's to_i method to convert num to an integer.



# File 'numeric.c'

/*
 *  call-seq:
 *     num.to_int    => integer
 *
 *  Invokes the child class's <code>to_i</code> method to convert
 *  <i>num</i> to an integer.
 */

static VALUE
num_to_int(num)
    VALUE num;
{
    return rb_funcall(num, id_to_i, 0, 0);
}

- (Integer) truncate

Returns num truncated to an integer. Numeric implements this by converting its value to a float and invoking Float#truncate.



# File 'numeric.c'

/*
 *  call-seq:
 *     num.truncate    => integer
 *
 *  Returns <i>num</i> truncated to an integer. <code>Numeric</code>
 *  implements this by converting its value to a float and invoking
 *  <code>Float#truncate</code>.
 */

static VALUE
num_truncate(num)
    VALUE num;
{
    return flo_truncate(rb_Float(num));
}

- (Boolean) zero?

Returns true if num has a zero value.



# File 'numeric.c'

/*
 *  call-seq:
 *     num.zero?    => true or false
 *
 *  Returns <code>true</code> if <i>num</i> has a zero value.
 */

static VALUE
num_zero_p(num)
    VALUE num;
{
    if (rb_equal(num, INT2FIX(0))) {
    return Qtrue;
    }
    return Qfalse;
}