--- ray/doc/man/man1/rcalc.1	2003/12/09 15:59:06	1.4
+++ ray/doc/man/man1/rcalc.1	2022/03/13 16:11:48	1.17
@@ -1,4 +1,4 @@
-.\" RCSid "$Id: rcalc.1,v 1.4 2003/12/09 15:59:06 greg Exp $"
+.\" RCSid "$Id: rcalc.1,v 1.17 2022/03/13 16:11:48 greg Exp $"
 .TH RCALC 1 4/6/99 RADIANCE
 .SH NAME
 rcalc - record calculator
@@ -9,6 +9,8 @@ rcalc - record calculator
 ][
 .B \-l
 ][
+.B "\-p | \-P"
+][
 .B \-n
 ][
 .B \-w
@@ -21,6 +23,10 @@ rcalc - record calculator
 ][
 .B "\-o format"
 ][
+.B "\-in M"
+][
+.B "\-on M"
+][
 .B "\-f source"
 ][
 .B "\-e expr"
@@ -54,6 +60,11 @@ A special form of the
 option may be followed immediately by a 'd' or an 'f' and an optional
 count, which defaults to 1, indicating the number of double or float
 binary values to read per record on the input file.
+If the input is byte-swapped, the
+.I \-iD
+or
+.I \-iF
+options may be substituted.
 If binary input is specified, no format string or file is needed.
 .PP
 A
@@ -66,10 +77,51 @@ or
 .I \-of
 options do not require a count, as this will be determined by the
 number of output channels in the given expressions.
+If byte-swapped output is desired, the
+.I \-oD
+or
+.I \-oF
+options may be substituted.
 .PP
+The
+.I \-p
+option specifies "passive mode," where characters that do not
+match the input format are passed unaltered to the output.
+If the
+.I \-P
+option is given instead, then valid input records that do not
+yield a positive
+.I cond
+value are similarly passed to the output.
+(See paragraph below.)\0
+These options options require that the
+.I \-i
+input format and
+.I \-o
+output format also be present.
+With both input and output formats, the passive mode can
+effectively substitute information in the middle of a file
+or stream without affecting the rest of the data.
+.PP
+If a
+.I \-in
+option is given with a positive integer argument,
+.I rcalc
+will stop processing input once it has loaded this number of records.
+Similarly, if a
+.I \-on
+option is present,
+.I rcalc
+will stop after producing this many records, which may be a smaller
+number if the
+.I cond
+variable is used.
+If multiple input files are given, these counts are continuous over
+the input and do not reset on each file.
+.PP
 The variable and function definitions in each
 .I \-f source
-file are read and compiled.
+file are read and compiled from the RADIANCE library where it is found.
 The
 .I \-e expr
 option can be used to define variables on the command line.
@@ -177,7 +229,8 @@ and the following operators:
 .PP
 	+  -  *  /  ^
 .PP
-Operators are evaluated left to right.
+Operators are evaluated left to right, except '^',
+which is right associative.
 Powers have the highest precedence; multiplication and
 division are evaluated before addition and subtraction.
 Expressions can be grouped with parentheses.
@@ -204,11 +257,19 @@ If
 is positive, output is produced.
 If
 .I cond
-is less than or equal to zero, the record is skipped and no other expressions
+is less than or equal to zero, the record is skipped (or passed to the
+output if
+.I \-P
+is specified) and no other expressions
 are evaluated.
 This provides a convenient method for avoiding inappropriate calculations.
 The following library of pre-defined functions and variables is provided:
 .TP 10n
+.BR $N
+Return the value for input column
+.I N.
+If an input format is given, using a channel number generates an error.
+.TP
 .BR "in(n)"
 Return the value for input column
 .I n,
@@ -219,8 +280,8 @@ This is an alternate way to get a column value instead
 the $N notation, and is more flexible since it is programmable.
 This function is disabled if an input format is used.
 .TP
-.BR "if(cond, then, else)"
-if cond is greater than zero,
+.BR "if(test, then, else)"
+if test is greater than zero,
 then is evaluated, otherwise else is evaluated.
 This function is necessary for recursive definitions.
 .TP
@@ -234,6 +295,12 @@ is zero, the number of available arguments is returned
 .BR "rand(x)"
 compute a random number between 0 and 1 based on x.
 .TP
+.BR "min(a1, a2, ..)"
+return the minimum value from a list of arguments.
+.TP
+.BR "max(a1, a2, ..)"
+return the maximum value from a list of arguments.
+.TP
 .BR "floor(x)"
 return largest integer not greater than x.
 .TP
@@ -268,12 +335,14 @@ trigonometric functions.
 inverse trigonometric functions.
 .TP
 .BR "atan2(y, x)"
-inverse tangent of y/x (range -pi to pi).
+inverse tangent of y/x (range \-pi to pi).
 .SH EXAMPLE
 To print the square root of column two in column one,
 and column one times column three in column two:
 .IP "" .2i
 rcalc -e '$1=sqrt($2);$2=$1*$3' inputfile > outputfile
+.SH ENVIRONMENT
+RAYPATH		the directories to check for auxiliary files.
 .SH AUTHOR
 Greg Ward
 .SH BUGS
@@ -282,5 +351,17 @@ String variables can only be used in input and output 
 options, not in definitions.
 .PP
 Tabs count as single spaces inside fields.
+.PP
+The
+.I \-P
+option buffers up to 16 Kbytes of data per record.
+Longer records passed because the "cond" variable
+evaluates to <= 0 will be partial; a warning will
+be generated and the string "*** MISSING DATA ***"
+will appear at the break.
+The only workaround is to use the
+.I \-p
+option instead, which does not pass rejected records.
 .SH "SEE ALSO"
-calc(1), cnt(1), ev(1), getinfo(1), lam(1), tabfunc(1), total(1)
+cnt(1), ev(1), getinfo(1), icalc(1), rcollate(1), rlam(1),
+rsplit(1), tabfunc(1), total(1)