# man pages section 1: User Commands

Updated: Wednesday, February 9, 2022

## mathfunc (1t)

### 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

```Tcl Mathematical Functions                                        mathfunc(1t)

______________________________________________________________________________

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::math-
func::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::math-
func  namespace.   In  addition,  an  obsolete interface named Tcl_Cre-
ateMathFunc() 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]  radi-
ans.

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 trian-
gle, 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 num-
ber.  Unlike sqrt, which is limited to the precision of a float-
ing point number, isqrt will return a result of arbitrary preci-
sion.

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  nega-
tive, 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  genera-
tor 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.

ATTRIBUTES
See attributes(7) for descriptions of the following attributes:

+---------------+------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE  |
+---------------+------------------+
|Availability   | runtime/tcl-8    |
+---------------+------------------+
|Stability      | Uncommitted      |
+---------------+------------------+

expr(n), mathop(n), namespace(n)

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>.

NOTES
Source code for open source software components in Oracle  Solaris  can