Provided by: tcl8.6-doc_8.6.5+dfsg-2_all 
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
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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>.