Provided by: tcl8.6-doc_8.6.9+dfsg-2_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, approximately
              “sqrt [expr {x*x+y*y}]” except for being  more  numerically  stable  when  the  two
              arguments have substantially different magnitudes.

       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 the wordSize element of the tcl_platform array.

       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>.