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authordkf <donal.k.fellows@manchester.ac.uk>2003-07-04 22:22:07 (GMT)
committerdkf <donal.k.fellows@manchester.ac.uk>2003-07-04 22:22:07 (GMT)
commit3d9d117b813f5c270d6580bd83f5dcbe5d68aa79 (patch)
treec1ebb13d1d962de788a7cace2540922584ac8009 /doc
parent0660514c8f0c2acc9b501b3dacf25ec326479e52 (diff)
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Tighened up wording of several expr operations to make them less inclined to
misinterpretation. [Bug 758488]
Diffstat (limited to 'doc')
-rw-r--r--doc/expr.n26
1 files changed, 14 insertions, 12 deletions
diff --git a/doc/expr.n b/doc/expr.n
index cdb6560..8508ee2 100644
--- a/doc/expr.n
+++ b/doc/expr.n
@@ -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 1.11 2003/07/04 22:22:07 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