Provided by: tcl8.5-doc_8.5.11-1ubuntu1_all bug

NAME

       mathfunc - Mathematical functions for Tcl expressions

SYNOPSIS

       package require Tcl 8.5

       ::tcl::mathfunc::abs arg
       ::tcl::mathfunc::acos arg
       ::tcl::mathfunc::asin arg
       ::tcl::mathfunc::atan arg
       ::tcl::mathfunc::atan2 y x
       ::tcl::mathfunc::bool arg
       ::tcl::mathfunc::ceil arg
       ::tcl::mathfunc::cos arg
       ::tcl::mathfunc::cosh arg
       ::tcl::mathfunc::double arg
       ::tcl::mathfunc::entier arg::tcl::mathfunc::exp arg
       ::tcl::mathfunc::floor arg
       ::tcl::mathfunc::fmod x y
       ::tcl::mathfunc::hypot x y
       ::tcl::mathfunc::int arg
       ::tcl::mathfunc::isqrt arg
       ::tcl::mathfunc::log arg
       ::tcl::mathfunc::log10 arg
       ::tcl::mathfunc::max arg ?arg ...?
       ::tcl::mathfunc::min arg ?arg ...?
       ::tcl::mathfunc::pow x y
       ::tcl::mathfunc::rand
       ::tcl::mathfunc::round arg
       ::tcl::mathfunc::sin arg
       ::tcl::mathfunc::sinh arg
       ::tcl::mathfunc::sqrt arg
       ::tcl::mathfunc::srand arg
       ::tcl::mathfunc::tan arg
       ::tcl::mathfunc::tanh arg
       ::tcl::mathfunc::wide arg

_________________________________________________________________

DESCRIPTION

       The  expr  command  handles  mathematical functions of the form sin($x) or atan2($y,$x) by
       converting  them  to   calls   of   the   form   [tcl::mathfunc::sin   [expr   {$x}]]   or
       [tcl::mathfunc::atan2  [expr {$y}] [expr {$x}]].  A number of math functions are available
       by default within the namespace ::tcl::mathfunc; these functions are  also  available  for
       code apart from expr, by invoking the given commands directly.

       Tcl supports the following mathematical functions in expressions, all of which work solely
       with        floating-point         numbers         unless         otherwise         noted:
       abs         acos        asin       atan             atan2       bool        ceil       cos
       cosh        double      entier     exp              floor       fmod        hypot      int
       isqrt       log         log10      max            min         pow         rand       round
       sin         sinh        sqrt       srand tan         tanh        wide

       In addition to these predefined functions, applications may define additional functions by
       using  proc  (or any other method, such as interp alias or Tcl_CreateObjCommand) to define
       new commands in the tcl::mathfunc namespace.  In addition,  an  obsolete  interface  named
       Tcl_CreateMathFunc()  is  available  to  extensions  that  are  written  in  C. The latter
       interface is not recommended for new implementations.

   DETAILED DEFINITIONS
       abs arg
              Returns the absolute value of arg.  Arg may be either  integer  or  floating-point,
              and the result is returned in the same form.

       acos arg
              Returns  the  arc  cosine of arg, in the range [0,pi] radians. Arg should be in the
              range [-1,1].

       asin arg
              Returns the arc sine of arg, in the range [-pi/2,pi/2] radians.  Arg should  be  in
              the range [-1,1].

       atan arg
              Returns the arc tangent of arg, in the range [-pi/2,pi/2] radians.

       atan2 y x
              Returns the arc tangent of y/x, in the range [-pi,pi] radians.  x and y cannot both
              be 0.  If x is greater than 0, this is equivalent to “atan [expr {y/x}]”.

       bool arg
              Accepts any numeric value, or any string  acceptable  to  string  is  boolean,  and
              returns  the corresponding boolean value 0 or 1.  Non-zero numbers are true.  Other
              numbers are false.  Non-numeric strings produce boolean  value  in  agreement  with
              string is true and string is false.

       ceil arg
              Returns  the  smallest  integral  floating-point value (i.e. with a zero fractional
              part) not less than arg.  The argument may be any numeric value.

       cos arg
              Returns the cosine of arg, measured in radians.

       cosh arg
              Returns the hyperbolic cosine of arg.  If the result would cause  an  overflow,  an
              error is returned.

       double arg
              The  argument  may  be any numeric value, If arg is a floating-point value, returns
              arg, otherwise converts arg to floating-point and returns the converted value.  May
              return  Inf or -Inf when the argument is a numeric value that exceeds the floating-
              point range.

       entier arg
              The argument may be any numeric value.  The integer part of arg is  determined  and │
              returned.  The integer range returned by this function is unlimited, unlike int and │
              wide which truncate their range to fit in particular storage widths.

       exp arg
              Returns the exponential of arg, defined as e**arg.  If the result  would  cause  an
              overflow, an error is returned.

       floor arg
              Returns  the  largest  integral  floating-point  value (i.e. with a zero fractional
              part) not greater than arg.  The argument may be any numeric value.

       fmod x y
              Returns the floating-point remainder of the division of x by y.   If  y  is  0,  an
              error is returned.

       hypot x y
              Computes  the  length  of  the  hypotenuse  of  a right-angled triangle “sqrt [expr
              {x*x+y*y}]”.

       int arg
              The argument may be any numeric value.  The integer part of arg is determined,  and
              then  the  low  order  bits  of  that integer value up to the machine word size are
              returned as an integer value.  For reference, the number of bytes  in  the  machine
              word are stored in tcl_platform(wordSize).

       isqrt arg
              Computes the integer part of the square root of arg.  Arg must be a positive value,
              either an integer or a floating point number.  Unlike sqrt, which is limited to the
              precision  of  a  floating  point  number,  isqrt will return a result of arbitrary
              precision.

       log arg
              Returns the natural logarithm of arg.  Arg must be a positive value.

       log10 arg
              Returns the base 10 logarithm of arg.  Arg must be a positive value.

       max arg ...
              Accepts one or more numeric arguments.  Returns the one argument with the  greatest
              value.

       min arg ...
              Accepts  one  or  more  numeric arguments.  Returns the one argument with the least
              value.

       pow x y
              Computes the value of x raised to the power y.  If x is  negative,  y  must  be  an
              integer value.

       rand   Returns  a  pseudo-random  floating-point  value in the range (0,1).  The generator
              algorithm is a simple linear congruential generator that is  not  cryptographically
              secure.   Each  result  from  rand  completely  determines  all future results from
              subsequent calls to rand, so rand should not be used  to  generate  a  sequence  of
              secrets, such as one-time passwords.  The seed of the generator is initialized from
              the internal clock of the machine or may be set with the srand function.

       round arg
              If arg is an integer value, returns arg,  otherwise  converts  arg  to  integer  by
              rounding and returns the converted value.

       sin arg
              Returns the sine of arg, measured in radians.

       sinh arg
              Returns  the  hyperbolic  sine  of  arg.  If the result would cause an overflow, an
              error is returned.

       sqrt arg
              The argument may be any non-negative numeric value.  Returns a floating-point value
              that  is  the  square  root  of arg.  May return Inf when the argument is a numeric
              value that exceeds the square of the maximum value of the floating-point range.

       srand arg
              The arg, which must be an integer, is used to reset the seed for the random  number
              generator  of  rand.   Returns  the  first random number (see rand) from that seed.
              Each interpreter has its own seed.

       tan arg
              Returns the tangent of arg, measured in radians.

       tanh arg
              Returns the hyperbolic tangent of arg.

       wide arg
              The argument may be any numeric value.  The integer part of arg is determined,  and
              then the low order 64 bits of that integer value are returned as an integer value.

SEE ALSO

       expr(3tcl), mathop(3tcl), namespace(3tcl)

COPYRIGHT

       Copyright (c) 1993 The Regents of the University of California.
       Copyright (c) 1994-2000 Sun Microsystems Incorporated.
       Copyright (c) 2005, 2006 by Kevin B. Kenny <kennykb@acm.org>.