diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/expr.n | 26 |
1 files changed, 14 insertions, 12 deletions
@@ -5,7 +5,7 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: expr.n,v 1.10 2003/01/03 23:03:22 dgp Exp $ +'\" RCS: @(#) $Id: expr.n,v 1.10.2.1 2003/07/04 22:25:23 dkf Exp $ '\" .so man.macros .TH expr n 8.4 Tcl "Tcl Built-In Commands" @@ -194,14 +194,15 @@ the Tcl parser will evaluate both \fB[a]\fR and \fB[b]\fR before invoking the \fBexpr\fR command. .SH "MATH FUNCTIONS" .PP -Tcl supports the following mathematical functions in expressions: +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 +\fBatan2\fR \fBfmod\fR \fBround\fR \fBwide\fR \fBceil\fR \fBhypot\fR \fBsin\fR \fBcos\fR \fBint\fR \fBsinh\fR .DE @@ -229,7 +230,7 @@ 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 +Returns the smallest integral floating-point value (i.e. with a zero fractional part) not less than \fIarg\fR. .TP \fBcos(\fIarg\fB)\fR @@ -240,15 +241,15 @@ 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 value, returns \fIarg\fR, otherwise converts -\fIarg\fR to floating and returns the converted value. +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 +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 @@ -261,7 +262,8 @@ Computes the length of the hypotenuse of a right-angled triangle .TP \fBint(\fIarg\fB)\fR .VS 8.4 -If \fIarg\fR is an integer value, returns \fIarg\fR, otherwise +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. @@ -280,7 +282,7 @@ 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). +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 @@ -305,7 +307,7 @@ Returns the square root of \fIarg\fR. \fIArg\fR must be non-negative. \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 from that seed. Each interpreter has its own seed. +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. @@ -315,8 +317,8 @@ Returns the hyperbolic tangent of \fIarg\fR. .TP \fBwide(\fIarg\fB)\fR .VS 8.4 -Converts \fIarg\fR to a value at least 64-bits wide (by sign-extension -if \fIarg\fR is a 32-bit number.) +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. .VE 8.4 .PP In addition to these predefined functions, applications may |