[Python-checkins] r58159 - python/trunk/Doc/library/decimal.rst

Fri Sep 14 23:29:53 CEST 2007

Author: facundo.batista
Date: Fri Sep 14 23:29:52 2007
New Revision: 58159
Modified:
 python/trunk/Doc/library/decimal.rst
Log:
Some additions (examples and a bit on the tutorial).
Modified: python/trunk/Doc/library/decimal.rst
==============================================================================

--- python/trunk/Doc/library/decimal.rst	(original)
+++ python/trunk/Doc/library/decimal.rst	Fri Sep 14 23:29:52 2007
@@ -128,6 +128,8 @@
 Decimal("3.14")
 >>> Decimal(str(2.0 ** 0.5))
 Decimal("1.41421356237")
+ >>> Decimal(2) ** Decimal("0.5")
+ Decimal("1.414213562373095048801688724")
 >>> Decimal("NaN")
 Decimal("NaN")
 >>> Decimal("-Infinity")
@@ -177,6 +179,17 @@
 >>> c % a
 Decimal("0.77")
 
+And some mathematic functions are also available to Decimal::
+
+ >>> Decimal(2).sqrt()
+ Decimal("1.414213562373095048801688724")
+ >>> Decimal(1).exp()
+ Decimal("2.718281828459045235360287471")
+ >>> Decimal("10").ln()
+ Decimal("2.302585092994045684017991455")
+ >>> Decimal("10").log10()
+ Decimal("1")
+
 The :meth:`quantize` method rounds a number to a fixed exponent. This method is
 useful for monetary applications that often round results to a fixed number of
 places::
@@ -419,6 +432,11 @@
 given number. The result is correctly rounded using the
 :const:`ROUND_HALF_EVEN` rounding mode.
 
+ >>> Decimal(1).exp()
+ Decimal("2.718281828459045235360287471")
+ >>> Decimal(321).exp()
+ Decimal("2.561702493119680037517373933E+139")
+
 .. versionadded:: 2.6
 
 .. method:: Decimal.fma(other, third[, context])
@@ -426,78 +444,82 @@
 Fused multiply-add. Return self*other+third with no rounding of
 the intermediate product self*other.
 
+ >>> Decimal(2).fma(3, 5)
+ Decimal("11")
+
 .. versionadded:: 2.6
 
 .. method:: Decimal.is_canonical()
 
- Return ``Decimal(1)`` if the argument is canonical and
- ``Decimal(0)`` otherwise. Currently, a :class:`Decimal` instance
+ Return :const:`True` if the argument is canonical and
+ :const:`False` otherwise. Currently, a :class:`Decimal` instance
 is always canonical, so this operation always returns
- ``Decimal(1)``.
+ :const:`True`.
 
 .. versionadded:: 2.6
 
 .. method:: is_finite()
 
- Return ``Decimal(1)`` if the argument is a finite number, and
- ``Decimal(0)`` if the argument is an infinity or a NaN.
+ Return :const:`True` if the argument is a finite number, and
+ :const:`False` if the argument is an infinity or a NaN.
 
 .. versionadded:: 2.6
 
 .. method:: is_infinite()
 
- Return ``Decimal(1)`` if the argument is either positive or
- negative infinity and ``Decimal(0)`` otherwise.
+ Return :const:`True` if the argument is either positive or
+ negative infinity and :const:`False` otherwise.
 
 .. versionadded:: 2.6
 
 .. method:: is_nan()
 
- Return ``Decimal(1)`` if the argument is a (quiet or signaling)
- NaN and ``Decimal(0)`` otherwise.
+ Return :const:`True` if the argument is a (quiet or signaling)
+ NaN and :const:`False` otherwise.
 
 .. versionadded:: 2.6
 
 .. method:: is_normal()
 
- Return ``Decimal(1)`` if the argument is a *normal* finite number.
- Return ``Decimal(0)`` if the argument is zero, subnormal, infinite
+ Return :const:`True` if the argument is a *normal* finite number.
+ Return :const:`False` if the argument is zero, subnormal, infinite
 or a NaN.
 
 .. versionadded:: 2.6
 
 .. method:: is_qnan()
 
- Return ``Decimal(1)`` if the argument is a quiet NaN, and ``Decimal(0)`` otherwise.
+ Return :const:`True` if the argument is a quiet NaN, and
+ :const:`False` otherwise.
 
 .. versionadded:: 2.6
 
 .. method:: is_signed()
 
- Return ``Decimal(1)`` if the argument has a negative sign and
- ``Decimal(0)`` otherwise. Note that zeros and NaNs can both carry
+ Return :const:`True` if the argument has a negative sign and
+ :const:`False` otherwise. Note that zeros and NaNs can both carry
 signs.
 
 .. versionadded:: 2.6
 
 .. method:: is_snan()
 
- Return ``Decimal(1)`` if the argument is a signaling NaN and
- ``Decimal(0)`` otherwise.
+ Return :const:`True` if the argument is a signaling NaN and
+ :const:`False` otherwise.
 
 .. versionadded:: 2.6
 
 .. method:: is_subnormal()
 
- Return ``Decimal(1)`` if the argument is subnormal, and
- ``Decimal(0)`` otherwise.
+ Return :const:`True` if the argument is subnormal, and
+ :const:`False` otherwise.
 
 .. versionadded:: 2.6
 
 .. method:: is_zero()
 
- Return ``Decimal(1)`` if the argument is a (positive or negative)
- zero and ``Decimal(0)`` otherwise.
+ Return :const:`True` if the argument is a (positive or negative)
+ zero and :const:`False` otherwise.
 
 .. versionadded:: 2.6
 
@@ -640,6 +662,9 @@
 Returns a value equal to the first operand after rounding and
 having the exponent of the second operand.
 
+ >>> Decimal("1.41421356").quantize(Decimal("1.000"))
+ Decimal("1.414")
+
 Unlike other operations, if the length of the coefficient after the
 quantize operation would be greater than precision, then an
 :const:`InvalidOperation` is signaled. This guarantees that, unless
