--- ray/doc/man/man1/rcalc.1	2013/09/05 17:53:22	1.10
+++ ray/doc/man/man1/rcalc.1	2022/03/11 22:50:13	1.16
@@ -1,4 +1,4 @@
-.\" RCSid "$Id: rcalc.1,v 1.10 2013/09/05 17:53:22 greg Exp $"
+.\" RCSid "$Id: rcalc.1,v 1.16 2022/03/11 22:50:13 greg Exp $"
 .TH RCALC 1 4/6/99 RADIANCE
 .SH NAME
 rcalc - record calculator
@@ -9,7 +9,7 @@ rcalc - record calculator
 ][
 .B \-l
 ][
-.B \-p
+.B "\-p | \-P"
 ][
 .B \-n
 ][
@@ -23,6 +23,10 @@ rcalc - record calculator
 ][
 .B "\-o format"
 ][
+.B "\-in M"
+][
+.B "\-on M"
+][
 .B "\-f source"
 ][
 .B "\-e expr"
@@ -83,18 +87,41 @@ The
 .I \-p
 option specifies "passive mode," where characters that do not
 match the input format are passed unaltered to the output.
-This option has no effect unless
+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
-is also specified, and does not make much sense unless
+input format and
 .I \-o
-is also given.
+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.
@@ -230,12 +257,15 @@ 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
+.BR $N
 Return the value for input column
 .I N.
 If an input format is given, using a channel number generates an error.
@@ -250,8 +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
@@ -265,6 +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
@@ -304,7 +340,9 @@ inverse tangent of y/x (range \-pi to pi).
 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
+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
@@ -314,4 +352,5 @@ options, not in definitions.
 .PP
 Tabs count as single spaces inside fields.
 .SH "SEE ALSO"
-cnt(1), ev(1), getinfo(1), icalc(1), rcollate(1), rlam(1), tabfunc(1), total(1)
+cnt(1), ev(1), getinfo(1), icalc(1), rcollate(1), rlam(1),
+rsplit(1), tabfunc(1), total(1)