mathfunc - Mathematical functions for Tcl expressions
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
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.
- 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.
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>.