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author | Kevin B Kenny <kennykb@acm.org> | 2005-05-10 18:33:37 (GMT) |
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committer | Kevin B Kenny <kennykb@acm.org> | 2005-05-10 18:33:37 (GMT) |
commit | 76e3b5eed61a674bce7f9c1e18380842dcff3fbf (patch) | |
tree | 2f108341f2c542f48532e6057d79bfa551a4245f /doc/mathfunc.n | |
parent | 5b510b75ec4a1d6fb55691bcf55dbf4b0b936624 (diff) | |
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Merged kennykb-numerics-branch back to the head; TIPs 132 and 232
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diff --git a/doc/mathfunc.n b/doc/mathfunc.n new file mode 100644 index 0000000..dfa4cb6 --- /dev/null +++ b/doc/mathfunc.n @@ -0,0 +1,221 @@ +.\" +'\" Copyright (c) 1993 The Regents of the University of California. +'\" Copyright (c) 1994-2000 Sun Microsystems, Inc. +'\" Copyright (c) 2005 by Kevin B. Kenny <kennykb@acm.org>. All rights reserved +'\" +'\" See the file "license.terms" for information on usage and redistribution +'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. +'\" +'\" RCS: @(#) $Id: mathfunc.n,v 1.2 2005/05/10 18:34:02 kennykb Exp $ +'\" +.so man.macros +.TH mathfunc n 8.5 Tcl "Tcl Mathematical Functions" +.BS +'\" Note: do not modify the .SH NAME line immediately below! +.SH NAME +expr \- Evaluate an expression +.SH SYNOPSIS +package require \fBTcl 8.5\fR +.sp +\fB::tcl::mathfunc::abs\fR \fIarg\fR +.br +\fB::tcl::mathfunc::acos\fR \fIarg\fR +.br +\fB::tcl::mathfunc::asin\fR \fIarg\fR +.br +\fB::tcl::mathfunc::atan\fR \fIarg\fR +.br +\fB::tcl::mathfunc::atan2\fR \fIy\fR \fIx\fR +.br +\fB::tcl::mathfunc::ceil\fR \fIarg\fR +.br +\fB::tcl::mathfunc::cos\fR \fIarg\fR +.br +\fB::tcl::mathfunc::cosh\fR \fIarg\fR +.br +\fB::tcl::mathfunc::double\fR \fIarg\fR +.br +\fB::tcl::mathfunc::exp\fR \fIarg\fR +.br +\fB::tcl::mathfunc::floor\fR \fIarg\fR +.br +\fB::tcl::mathfunc::fmod\fR \fIx\fR \fIy\fR +.br +\fB::tcl::mathfunc::hypot\fR \fIx\fR \fIy\fR +.br +\fB::tcl::mathfunc::int\fR \fIarg\fR +.br +\fB::tcl::mathfunc::log\fR \fIarg\fR +.br +\fB::tcl::mathfunc::log10\fR \fIarg\fR +.br +\fB::tcl::mathfunc::pow\fR \fIx\fR \fIy\fR +.br +\fB::tcl::mathfunc::rand\fR +.br +\fB::tcl::mathfunc::round\fR \fIarg\fR +.br +\fB::tcl::mathfunc::sin\fR \fIarg\fR +.br +\fB::tcl::mathfunc::sinh\fR \fIarg\fR +.br +\fB::tcl::mathfunc::sqrt\fR \fIarg\fR +.br +\fB::tcl::mathfunc::srand\fR \fIarg\fR +.br +\fB::tcl::mathfunc::tan\fR \fIarg\fR +.br +\fB::tcl::mathfunc::tanh\fR \fIarg\fR +.br +\fB::tcl::mathfunc::wide\fR \fIarg\fR +.sp +.BE +.SH "DESCRIPTION" +.PP +The \fBexpr\fR command handles mathematical functions of the form +\fBsin($x)\fR or \fBatan2($y,$x)\fR by converting them to calls of the +form \fB[tcl::math::sin [expr {$x}]]\fR or +\fB[tcl::math::atan2 [expr {$y}] [expr {$x}]]\fR. +A number of math functions are available by default within the +namespace \fB::tcl::mathfunc\fR; these functions are also available +for code apart from \fBexpr\fR, by invoking the given commands +directly. +.PP +Tcl supports the following mathematical functions in expressions, all +of which work solely with floating-point numbers unless otherwise noted: +.DS +.ta 3c 6c 9c +\fBabs\fR \fBcosh\fR \fBlog\fR \fBsqrt\fR +\fBacos\fR \fBdouble\fR \fBlog10\fR \fBsrand\fR +\fBasin\fR \fBexp\fR \fBpow\fR \fBtan\fR +\fBatan\fR \fBfloor\fR \fBrand\fR \fBtanh\fR +\fBatan2\fR \fBfmod\fR \fBround\fR \fBwide\fR +\fBceil\fR \fBhypot\fR \fBsin\fR +\fBcos\fR \fBint\fR \fBsinh\fR +.DE +.PP +.TP +\fBabs(\fIarg\fB)\fR +Returns the absolute value of \fIarg\fR. \fIArg\fR may be either +integer or floating-point, and the result is returned in the same form. +.TP +\fBacos(\fIarg\fB)\fR +Returns the arc cosine of \fIarg\fR, in the range [\fI0\fR,\fIpi\fR] +radians. \fIArg\fR should be in the range [\fI-1\fR,\fI1\fR]. +.TP +\fBasin(\fIarg\fB)\fR +Returns the arc sine of \fIarg\fR, in the range [\fI-pi/2\fR,\fIpi/2\fR] +radians. \fIArg\fR should be in the range [\fI-1\fR,\fI1\fR]. +.TP +\fBatan(\fIarg\fB)\fR +Returns the arc tangent of \fIarg\fR, in the range [\fI-pi/2\fR,\fIpi/2\fR] +radians. +.TP +\fBatan2(\fIy, x\fB)\fR +Returns the arc tangent of \fIy\fR/\fIx\fR, in the range [\fI-pi\fR,\fIpi\fR] +radians. \fIx\fR and \fIy\fR cannot both be 0. If \fIx\fR is greater +than \fI0\fR, this is equivalent to \fBatan(\fIy/x\fB)\fR. +.TP +\fBceil(\fIarg\fB)\fR +Returns the smallest integral floating-point value (i.e. with a zero +fractional part) not less than \fIarg\fR. +.TP +\fBcos(\fIarg\fB)\fR +Returns the cosine of \fIarg\fR, measured in radians. +.TP +\fBcosh(\fIarg\fB)\fR +Returns the hyperbolic cosine of \fIarg\fR. If the result would cause +an overflow, an error is returned. +.TP +\fBdouble(\fIarg\fB)\fR +If \fIarg\fR is a floating-point value, returns \fIarg\fR, otherwise converts +\fIarg\fR to floating-point and returns the converted value. +.TP +\fBexp(\fIarg\fB)\fR +Returns the exponential of \fIarg\fR, defined as \fIe\fR**\fIarg\fR. +If the result would cause an overflow, an error is returned. +.TP +\fBfloor(\fIarg\fB)\fR +Returns the largest integral floating-point value (i.e. with a zero +fractional part) not greater than \fIarg\fR. +.TP +\fBfmod(\fIx, y\fB)\fR +Returns the floating-point remainder of the division of \fIx\fR by +\fIy\fR. If \fIy\fR is 0, an error is returned. +.TP +\fBhypot(\fIx, y\fB)\fR +Computes the length of the hypotenuse of a right-angled triangle +\fBsqrt(\fIx\fR*\fIx\fR+\fIy\fR*\fIy\fB)\fR. +.TP +\fBint(\fIarg\fB)\fR +If \fIarg\fR is an integer value of the same width as the machine +word, returns \fIarg\fR, otherwise +converts \fIarg\fR to an integer (of the same size as a machine word, +i.e. 32-bits on 32-bit systems, and 64-bits on 64-bit systems) by +truncation and returns the converted value. +.TP +\fBlog(\fIarg\fB)\fR +Returns the natural logarithm of \fIarg\fR. \fIArg\fR must be a +positive value. +.TP +\fBlog10(\fIarg\fB)\fR +Returns the base 10 logarithm of \fIarg\fR. \fIArg\fR must be a +positive value. +.TP +\fBpow(\fIx, y\fB)\fR +Computes the value of \fIx\fR raised to the power \fIy\fR. If \fIx\fR +is negative, \fIy\fR must be an integer value. +.TP +\fBrand()\fR +Returns a pseudo-random floating-point value in the range (\fI0\fR,\fI1\fR). +The generator algorithm is a simple linear congruential generator that +is not cryptographically secure. Each result from \fBrand\fR completely +determines all future results from subsequent calls to \fBrand\fR, so +\fBrand\fR 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 \fBsrand\fR function. +.TP +\fBround(\fIarg\fB)\fR +If \fIarg\fR is an integer value, returns \fIarg\fR, otherwise converts +\fIarg\fR to integer by rounding and returns the converted value. +.TP +\fBsin(\fIarg\fB)\fR +Returns the sine of \fIarg\fR, measured in radians. +.TP +\fBsinh(\fIarg\fB)\fR +Returns the hyperbolic sine of \fIarg\fR. If the result would cause +an overflow, an error is returned. +.TP +\fBsqrt(\fIarg\fB)\fR +Returns the square root of \fIarg\fR. \fIArg\fR must be non-negative. +.TP +\fBsrand(\fIarg\fB)\fR +The \fIarg\fR, which must be an integer, is used to reset the seed for +the random number generator of \fBrand\fR. Returns the first random +number (see \fBrand()\fR) from that seed. Each interpreter has its own seed. +.TP +\fBtan(\fIarg\fB)\fR +Returns the tangent of \fIarg\fR, measured in radians. +.TP +\fBtanh(\fIarg\fB)\fR +Returns the hyperbolic tangent of \fIarg\fR. +.TP +\fBwide(\fIarg\fB)\fR +Converts \fIarg\fR to an integer value at least 64-bits wide (by sign-extension +if \fIarg\fR is a 32-bit number) if it is not one already. +.PP +In addition to these predefined functions, applications may +define additional functions by using \fBproc\fR (or any other method, +such as \fBinterp alias\fR or \fBTcl_CreateObjCommand\fR) to define +new commands in the \fBtcl::mathfunc\fR namespace. In addition, an +obsolete interface named \fBTcl_CreateMathFunc\fR() is available to +extensions that are written in C. The latter interface is not recommended +for new implementations.. +.SH "SEE ALSO" +expr(n), namespace(n) +.SH "COPYRIGHT" +Copyright (c) 1993 The Regents of the University of California. +.br +Copyright (c) 1994-2000 Sun Microsystems Incorporated. +.br +Copyright (c) 2005 by Kevin B. Kenny <kennykb@acm.org>. All rights reserved.
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