Provided by: tcllib_1.14-dfsg-1_all bug

NAME

       ::Decimal - General decimal arithmetic

SYNOPSIS

       package require Tcl  ?8.5?

       ::Decimal::fromstr string

       ::Decimal::tostr decimal

       ::Decimal::setVariable variable setting

       ::Decimal::add a b

       ::Decimal::+ a b

       ::Decimal::subtract a b

       ::Decimal::- a b

       ::Decimal::multiply a b

       ::Decimal::* a b

       ::Decimal::divide a b

       ::Decimal::/ a b

       ::Decimal::divideint a b

       ::Decimal::remainder a b

       ::Decimal::abs decimal

       ::Decimal::compare a b

       ::Decimal::max a b

       ::Decimal::maxmag a b

       ::Decimal::min a b

       ::Decimal::minmag a b

       ::Decimal::plus a

       ::Decimal::minus a

       ::Decimal::copynegate a

       ::Decimal::copysign a b

       ::Decimal::is-signed decimal

       ::Decimal::is-zero decimal

       ::Decimal::is-NaN decimal

       ::Decimal::is-infinite decimal

       ::Decimal::is-finite decimal

       ::Decimal::fma a b c

       ::Decimal::round_half_even decimal digits

       ::Decimal::round_half_up decimal digits

       ::Decimal::round_half_down decimal digits

       ::Decimal::round_down decimal digits

       ::Decimal::round_up decimal digits

       ::Decimal::round_floor decimal digits

       ::Decimal::round_ceiling decimal digits

       ::Decimal::round_05up decimal digits

_________________________________________________________________

DESCRIPTION

       The  decimal  package  provides  decimal  arithmetic  support  for  both limited precision
       floating point and arbitrary precision floating point.  Additionally,  integer  arithmetic
       is supported.

       More  information and the specifications on which this package depends can be found on the
       general decimal arithmetic page at http://speleotrove.com/decimal  This  package  provides
       for:

       ·      A  new  data  type decimal which is represented as a list containing sign, mantissa
              and exponent.

       ·      Arithmetic operations on those  decimal  numbers  such  as  addition,  subtraction,
              multiplication, etc...

       Numbers are converted to decimal format using the operation ::Decimal::fromstr.

       Numbers are converted back to string format using the operation ::Decimal::tostr.

EXAMPLES

       This  section  shows some simple examples. Since the purpose of this library is to perform
       decimal math operations, examples may be the simplest way to learn how to work with it and
       to  see  the difference between using this package and sticking with expr. Consult the API
       section of this man page for information about individual procedures.

                  package require decimal

                  # Various operations on two numbers.
                  # We first convert them to decimal format.
                  set a [::Decimal::fromstr 8.2]
                  set b [::Decimal::fromstr .2]

                  # Then we perform our operations. Here we multiply
                  set c [::Decimal::* $a $b]

                  # Finally we convert back to string format for presentation to the user.
                  puts [::Decimal::tostr $c] ; # => will output 8.4

                  # Other examples
                  #
                  # Subtraction
                  set c [::Decimal::- $a $b]
                  puts [::Decimal::tostr $c] ; # => will output 8.0

                  # Why bother using this instead of simply expr?
                  puts 8.399999999999999 ; # => will output 8.399999999999999
                  puts 7.999999999999999 ; # => will output 7.999999999999999
                  # See http://speleotrove.com/decimal to learn more about why this happens.

API

       ::Decimal::fromstr string
              Convert string into a decimal.

       ::Decimal::tostr decimal
              Convert decimal into a string representing the number in base 10.

       ::Decimal::setVariable variable setting
              Sets the variable to setting. Valid variables are:

              ·      rounding - Method of rounding to  use  during  rescale.  Valid  methods  are
                     round_half_even,   round_half_up,   round_half_down,  round_down,  round_up,
                     round_floor, round_ceiling.

              ·      precision - Maximum number of digits allowed in mantissa.

              ·      extended - Set to 1 for extended mode. 0 for simplified mode.

              ·      maxExponent - Maximum value for the exponent. Defaults to 999.

              ·      minExponent - Minimum value for the exponent. Default to -998.

       ::Decimal::add a b

       ::Decimal::+ a b
              Return the sum of the two decimals a and b.

       ::Decimal::subtract a b

       ::Decimal::- a b
              Return the differnece of the two decimals a and b.

       ::Decimal::multiply a b

       ::Decimal::* a b
              Return the product of the two decimals a and b.

       ::Decimal::divide a b

       ::Decimal::/ a b
              Return the quotient of the division between the two decimals a and b.

       ::Decimal::divideint a b
              Return a the integer portion of the quotient of the division between decimals a and
              b

       ::Decimal::remainder a b
              Return the remainder of the division between the two decimals a and b.

       ::Decimal::abs decimal
              Return the absolute value of the decimal.

       ::Decimal::compare a b
              Compare  the two decimals a and b, returning 0 if a == b, 1 if a > b, and -1 if a <
              b.

       ::Decimal::max a b
              Compare the two decimals a and b, and return a if a >= b, and b if a < b.

       ::Decimal::maxmag a b
              Compare the two decimals a and b while ignoring their signs, and return a if abs(a)
              >= abs(b), and b if abs(a) < abs(b).

       ::Decimal::min a b
              Compare the two decimals a and b, and return a if a <= b, and b if a > b.

       ::Decimal::minmag a b
              Compare the two decimals a and b while ignoring their signs, and return a if abs(a)
              <= abs(b), and b if abs(a) > abs(b).

       ::Decimal::plus a
              Return the result from ::Decimal::+ 0 $a.

       ::Decimal::minus a
              Return the result from ::Decimal::- 0 $a.

       ::Decimal::copynegate a
              Returns a with the sign flipped.

       ::Decimal::copysign a b
              Returns a with the sign set to the sign of the b.

       ::Decimal::is-signed decimal
              Return the sign of the decimal.  The procedure returns 0 if the number is positive,
              1 if it's negative.

       ::Decimal::is-zero decimal
              Return true if decimal value is zero, otherwise false is returned.

       ::Decimal::is-NaN decimal
              Return true if decimal value is NaN (not a number), otherwise false is returned.

       ::Decimal::is-infinite decimal
              Return true if decimal value is Infinite, otherwise false is returned.

       ::Decimal::is-finite decimal
              Return true if decimal value is finite, otherwise false is returned.

       ::Decimal::fma a b c
              Return  the  result from first multiplying a by b and then adding c. Rescaling only
              occurs after completion of all operations. In this way the  result  may  vary  from
              that returned by performing the operations individually.

       ::Decimal::round_half_even decimal digits
              Rounds  decimal  to digits number of decimal points with the following rules: Round
              to the nearest. If equidistant, round so the final digit is even.

       ::Decimal::round_half_up decimal digits
              Rounds decimal to digits number of decimal points with the following  rules:  Round
              to the nearest. If equidistant, round up.

       ::Decimal::round_half_down decimal digits
              Rounds  decimal  to digits number of decimal points with the following rules: Round
              to the nearest. If equidistant, round down.

       ::Decimal::round_down decimal digits
              Rounds decimal to digits number of decimal points with the following  rules:  Round
              toward 0.  (Truncate)

       ::Decimal::round_up decimal digits
              Rounds  decimal  to digits number of decimal points with the following rules: Round
              away from 0

       ::Decimal::round_floor decimal digits
              Rounds decimal to digits number of decimal points with the following  rules:  Round
              toward -Infinity.

       ::Decimal::round_ceiling decimal digits
              Rounds  decimal  to digits number of decimal points with the following rules: Round
              toward Infinity

       ::Decimal::round_05up decimal digits
              Rounds decimal to digits number of decimal points with the following  rules:  Round
              zero or five away from 0. The same as round-up, except that rounding up only occurs
              if the digit to be rounded up is 0 or 5, and after overflow the result is the  same
              as for round-down.

BUGS, IDEAS, FEEDBACK

       This  document,  and  the  package  it  describes, will undoubtedly contain bugs and other
       problems.  Please  report  such  in  the  category  Decimal  of  the  Tcllib  SF  Trackers
       [http://sourceforge.net/tracker/?group_id=12883].    Please  also  report  any  ideas  for
       enhancements you may have for either package and/or documentation.

KEYWORDS

       decimal, math, tcl

CATEGORY

       Mathematics

COPYRIGHT

       Copyright (c) 2011 Mark Alston <mark at beernut dot com>