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mathfunc(3tcl) Tcl Mathematical Functions mathfunc(3tcl) 





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



  

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

  

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

  

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

  

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

  

  
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}]”.

  

  
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.

  

  
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.

  

  
Returns the cosine of arg, measured in radians.

  

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

  

  
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.

  

  
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.

  

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

  

  
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.

  

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

  

  
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.

  

  
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.

  

  
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.

  

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

  

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

  

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

  

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

  

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

  

  
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.

  

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

  

  
Returns the sine of arg, measured in radians.

  

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

  

  
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.

  

  
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.

  

  
Returns the tangent of arg, measured in radians.

  

  
Returns the hyperbolic tangent of 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 © 1993 The Regents of the University of California.
Copyright © 1994-2000 Sun Microsystems Incorporated.
Copyright © 2005, 2006 Kevin B. Kenny <kennykb@acm.org>.







  

    8.5
    Tcl