'\" '\" Copyright (c) 1989-1993 The Regents of the University of California. '\" Copyright (c) 1994-1996 Sun Microsystems, Inc. '\" '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" '\" SCCS: @(#) CrtMathFnc.3 1.9 96/08/26 12:59:43 '\" '\" The definitions below are for supplemental macros used in Tcl/Tk '\" manual entries. '\" '\" .AP type name in/out ?indent? '\" Start paragraph describing an argument to a library procedure. '\" type is type of argument (int, etc.), in/out is either "in", "out", '\" or "in/out" to describe whether procedure reads or modifies arg, '\" and indent is equivalent to second arg of .IP (shouldn't ever be '\" needed; use .AS below instead) '\" '\" .AS ?type? ?name? '\" Give maximum sizes of arguments for setting tab stops. Type and '\" name are examples of largest possible arguments that will be passed '\" to .AP later. If args are omitted, default tab stops are used. '\" '\" .BS '\" Start box enclosure. From here until next .BE, everything will be '\" enclosed in one large box. '\" '\" .BE '\" End of box enclosure. '\" '\" .CS '\" Begin code excerpt. '\" '\" .CE '\" End code excerpt. '\" '\" .VS ?version? ?br? '\" Begin vertical sidebar, for use in marking newly-changed parts '\" of man pages. The first argument is ignored and used for recording '\" the version when the .VS was added, so that the sidebars can be '\" found and removed when they reach a certain age. If another argument '\" is present, then a line break is forced before starting the sidebar. '\" '\" .VE '\" End of vertical sidebar. '\" '\" .DS '\" Begin an indented unfilled display. '\" '\" .DE '\" End of indented unfilled display. '\" '\" .SO '\" Start of list of standard options for a Tk widget. The '\" options follow on successive lines, in four columns separated '\" by tabs. '\" '\" .SE '\" End of list of standard options for a Tk widget. '\" '\" .OP cmdName dbName dbClass '\" Start of description of a specific option. cmdName gives the '\" option's name as specified in the class command, dbName gives '\" the option's name in the option database, and dbClass gives '\" the option's class in the option database. '\" '\" .UL arg1 arg2 '\" Print arg1 underlined, then print arg2 normally. '\" '\" SCCS: @(#) man.macros 1.9 97/08/22 18:50:59 '\" '\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages. .if t .wh -1.3i ^B .nr ^l \n(.l .ad b '\" # Start an argument description .de AP .ie !"\\$4"" .TP \\$4 .el \{\ . ie !"\\$2"" .TP \\n()Cu . el .TP 15 .\} .ie !"\\$3"" \{\ .ta \\n()Au \\n()Bu \&\\$1 \\fI\\$2\\fP (\\$3) .\".b .\} .el \{\ .br .ie !"\\$2"" \{\ \&\\$1 \\fI\\$2\\fP .\} .el \{\ \&\\fI\\$1\\fP .\} .\} .. '\" # define tabbing values for .AP .de AS .nr )A 10n .if !"\\$1"" .nr )A \\w'\\$1'u+3n .nr )B \\n()Au+15n .\" .if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n .nr )C \\n()Bu+\\w'(in/out)'u+2n .. .AS Tcl_Interp Tcl_CreateInterp in/out '\" # BS - start boxed text '\" # ^y = starting y location '\" # ^b = 1 .de BS .br .mk ^y .nr ^b 1u .if n .nf .if n .ti 0 .if n \l'\\n(.lu\(ul' .if n .fi .. '\" # BE - end boxed text (draw box now) .de BE .nf .ti 0 .mk ^t .ie n \l'\\n(^lu\(ul' .el \{\ .\" Draw four-sided box normally, but don't draw top of .\" box if the box started on an earlier page. .ie !\\n(^b-1 \{\ \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' .\} .el \}\ \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' .\} .\} .fi .br .nr ^b 0 .. '\" # VS - start vertical sidebar '\" # ^Y = starting y location '\" # ^v = 1 (for troff; for nroff this doesn't matter) .de VS .if !"\\$2"" .br .mk ^Y .ie n 'mc \s12\(br\s0 .el .nr ^v 1u .. '\" # VE - end of vertical sidebar .de VE .ie n 'mc .el \{\ .ev 2 .nf .ti 0 .mk ^t \h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n' .sp -1 .fi .ev .\} .nr ^v 0 .. '\" # Special macro to handle page bottom: finish off current '\" # box/sidebar if in box/sidebar mode, then invoked standard '\" # page bottom macro. .de ^B .ev 2 'ti 0 'nf .mk ^t .if \\n(^b \{\ .\" Draw three-sided box if this is the box's first page, .\" draw two sides but no top otherwise. .ie !\\n(^b-1 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c .el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c .\} .if \\n(^v \{\ .nr ^x \\n(^tu+1v-\\n(^Yu \kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c .\} .bp 'fi .ev .if \\n(^b \{\ .mk ^y .nr ^b 2 .\} .if \\n(^v \{\ .mk ^Y .\} .. '\" # DS - begin display .de DS .RS .nf .sp .. '\" # DE - end display .de DE .fi .RE .sp .. '\" # SO - start of list of standard options .de SO .SH "STANDARD OPTIONS" .LP .nf .ta 4c 8c 12c .ft B .. '\" # SE - end of list of standard options .de SE .fi .ft R .LP See the \\fBoptions\\fR manual entry for details on the standard options. .. '\" # OP - start of full description for a single option .de OP .LP .nf .ta 4c Command-Line Name: \\fB\\$1\\fR Database Name: \\fB\\$2\\fR Database Class: \\fB\\$3\\fR .fi .IP .. '\" # CS - begin code excerpt .de CS .RS .nf .ta .25i .5i .75i 1i .. '\" # CE - end code excerpt .de CE .fi .RE .. .de UL \\$1\l'|0\(ul'\\$2 .. .TH Tcl_CreateMathFunc 3 7.0 Tcl "Tcl Library Procedures" .BS .SH NAME Tcl_CreateMathFunc \- Define a new math function for expressions .SH SYNOPSIS .nf \fB#include \fR .sp \fBTcl_CreateMathFunc\fR(\fIinterp, name, numArgs, argTypes, proc, clientData\fR) .SH ARGUMENTS .AS Tcl_ValueType clientData .AP Tcl_Interp *interp in Interpreter in which new function will be defined. .AP char *name in Name for new function. .AP int numArgs in Number of arguments to new function; also gives size of \fIargTypes\fR array. .AP Tcl_ValueType *argTypes in Points to an array giving the permissible types for each argument to function. .AP Tcl_MathProc *proc in Procedure that implements the function. .AP ClientData clientData in Arbitrary one-word value to pass to \fIproc\fR when it is invoked. .BE .SH DESCRIPTION .PP Tcl allows a number of mathematical functions to be used in expressions, such as \fBsin\fR, \fBcos\fR, and \fBhypot\fR. \fBTcl_CreateMathFunc\fR allows applications to add additional functions to those already provided by Tcl or to replace existing functions. \fIName\fR is the name of the function as it will appear in expressions. If \fIname\fR doesn't already exist as a function then a new function is created. If it does exist, then the existing function is replaced. \fINumArgs\fR and \fIargTypes\fR describe the arguments to the function. Each entry in the \fIargTypes\fR array must be either TCL_INT, TCL_DOUBLE, or TCL_EITHER to indicate whether the corresponding argument must be an integer, a double-precision floating value, or either, respectively. .PP Whenever the function is invoked in an expression Tcl will invoke \fIproc\fR. \fIProc\fR should have arguments and result that match the type \fBTcl_MathProc\fR: .CS typedef int Tcl_MathProc( ClientData \fIclientData\fR, Tcl_Interp *\fIinterp\fR, Tcl_Value *\fIargs\fR, Tcl_Value *\fIresultPtr\fR); .CE .PP When \fIproc\fR is invoked the \fIclientData\fR and \fIinterp\fR arguments will be the same as those passed to \fBTcl_CreateMathFunc\fR. \fIArgs\fR will point to an array of \fInumArgs\fR Tcl_Value structures, which describe the actual arguments to the function: .CS typedef struct Tcl_Value { Tcl_ValueType \fItype\fR; long \fIintValue\fR; double \fIdoubleValue\fR; } Tcl_Value; .CE .PP The \fItype\fR field indicates the type of the argument and is either TCL_INT or TCL_DOUBLE. It will match the \fIargTypes\fR value specified for the function unless the \fIargTypes\fR value was TCL_EITHER. Tcl converts the argument supplied in the expression to the type requested in \fIargTypes\fR, if that is necessary. Depending on the value of the \fItype\fR field, the \fIintValue\fR or \fIdoubleValue\fR field will contain the actual value of the argument. .PP \fIProc\fR should compute its result and store it either as an integer in \fIresultPtr->intValue\fR or as a floating value in \fIresultPtr->doubleValue\fR. It should set also \fIresultPtr->type\fR to either TCL_INT or TCL_DOUBLE to indicate which value was set. Under normal circumstances \fIproc\fR should return TCL_OK. If an error occurs while executing the function, \fIproc\fR should return TCL_ERROR and leave an error message in \fIinterp->result\fR. .SH KEYWORDS expression, mathematical function