man/man1/rcalc.1

.\" RCSid "$Id: rcalc.1,v 1.14 2019/06/10 13:56:52 greg Exp $"
.TH RCALC 1 4/6/99 RADIANCE
.SH NAME
rcalc - record calculator
.SH SYNOPSIS
.B rcalc
[
.B \-b
][
.B \-l
][
.B \-p
][
.B \-n
][
.B \-w
][
.B \-u
][
.B \-tS
][
.B "\-i format"
][
.B "\-o format"
][
.B "\-in M"
][
.B "\-on M"
][
.B "\-f source"
][
.B "\-e expr"
][
.B "\-s svar=sval"
]
file ..
.SH DESCRIPTION
.I Rcalc
transforms ``records'' from each
.I file
according to the given set of literal and relational information.
By default, records are separated by newlines, and contain
numeric fields separated by tabs.
The
.I \-tS
option is used to specify an alternate tab character.
.PP
A
.I \-i format
option specifies a template for an alternate
input record format.
.I Format
is interpreted as a specification string if it contains a dollar sign '$'.
Otherwise, it is interpreted as the name of the file containing
the format specification.
In either case, if the format does not end with a newline, one will be added
automatically.
A special form of the
.I \-i
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
.I \-o format
option specifies an alternate output record format.
It is interpreted the same as an input specification, except that
the special
.I \-od
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.
This option has no effect unless
.I \-i
is also specified, and does not make much sense unless
.I \-o
is also given.
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 from the RADIANCE library where it is found.
The
.I \-e expr
option can be used to define variables on the command line.
Since many of the characters in an expression have special meaning
to the shell, it should usually be enclosed in single quotes.
The
.I \-s svar=sval
option can be used to assign a string variable a string value.
If this string variable appears in an input format, only records
with the specified value will be processed.
.PP
The
.I \-b
option instructs the program to accept only exact matches.
By default, tabs and spaces are ignored except
as field separators.
The
.I \-l
option instructs the program to ignore newlines in the input,
basically treating them the same as tabs and spaces.
Normally, the beginning of the input format matches the beginning of
a line, and the end of the format matches the end of a line.
With the
.I \-l
option, the input format can match anywhere on a line.
.PP
The
.I \-w
option causes non-fatal error messages (such as division by zero) to
be supressed.
The
.I \-u
option causes output to be flushed after each record.
The
.I \-n
option tells the program not to get any input, but to produce a
single output record.
Otherwise, if no files are given, the standard input is read.
.PP
Format files associate names with string and numeric fields
separated by literal information in a record.
A numeric field is given in a format file as a dollar sign, followed
by curly braces enclosing a variable name:
.PP
        This is a numeric field: ${vname}
.PP
A string variable is enclosed in parentheses:
.PP
        This is a string field: $(sname)
.PP
The program attempts to match literal information in
the input format to its input and assign string and numeric
fields accordingly.
If a string or numeric field variable appears more than once in
the input format, input values for the corresponding fields must
match (ie. have the same value) for the whole record to match.
Numeric values are allowed some deviation, on the order of 0.1%, but
string variables must match exactly.
Thus, dummy variables for "don't care" fields should be given unique
names so that they are not all required to take on the same value.
.PP
For each valid input record, an output record is produced
in its corresponding format.
Output field widths are given implicitly by the space occupied
in the format file, including the dollar sign and braces.
This makes it impossible to produce fields with fewer than four
characters.
If the
.I \-b
option is specified, input records must exactly match the
template.
By default, the character following each input field is used as
a delimiter.
This implies that string fields that are followed by white space
cannot contain strings with white space.
Also, numeric fields followed but not preceded by white space
will not accept numbers preceded by white space.
Adjacent input fields are advisable only with the
.I \-b
option.
Numeric output fields may contain expressions as well as variables.
A dollar sign may appear in a literal as two dollar signs ($$).
.PP
The definitions specified in
.I \-e
and
.I \-f
options relate numeric output fields to numeric input fields.
For the default record format, a field is a variable of the form
$N, where N is the column number, beginning with 1.
Output columns appear on the left-hand side of assignments, input
columns appear on the right-hand side.
.PP
A variable definition has the form:
.PP

        var = expression ;

.PP
Any instance of the variable in an expression will be replaced
with its definition.
.PP
An expression contains real numbers, variable names, function calls,
and the following operators:
.PP
        +  -  *  /  ^
.PP
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.
All values are double precision real.
.PP
A function definition has the form:
.PP

        func(a1, a2, ..) = expression ;

.PP
The expression can contain instances of the function arguments
as well as other variables and functions.
Function names can be passed as arguments.
Recursive functions can be defined using calls to the defined
function or other functions calling the defined function.
.PP
The variable
.I cond,
if defined, will determine whether the current input record produces
an output record.
If
.I cond
is positive, output is produced.
If
.I cond
is less than or equal to zero, the record is skipped 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,
or the number of columns available in this record if
.I n
is 0.
This is an alternate way to get a column value instead of using
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,
then is evaluated, otherwise else is evaluated.
This function is necessary for recursive definitions.
.TP
.BR "select(N, a1, a2, ..)"
return aN (N is rounded to the nearest integer).
This function provides array capabilities.
If
.I N
is zero, the number of available arguments is returned.
.TP
.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
.BR "ceil(x)"
return smallest integer not less than x.
.TP
.BR "sqrt(x)"
return square root of x.
.TP
.BR "exp(x)"
compute e to the power of x (e approx = 2.718281828).
.TP
.BR "log(x)"
compute the logarithm of x to the base e.
.TP
.BR "log10(x)"
compute the logarithm of x to the base 10.
.TP
.BR PI
the ratio of a circle's circumference to its diameter.
.TP
.BR recno
the number of records recognized thus far.
.TP
.BR outno
the number or records output thus far (including this one).
.TP
.BR "sin(x), cos(x), tan(x)"
trigonometric functions.
.TP
.BR "asin(x), acos(x), atan(x)"
inverse trigonometric functions.
.TP
.BR "atan2(y, x)"
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*$3' inputfile > outputfile
.SH ENVIRONMENT
RAYPATH         the directories to check for auxiliary files.
.SH AUTHOR
Greg Ward
.SH BUGS
String variables can only be used in input and output formats and
.I \-s
options, not in definitions.
.PP
Tabs count as single spaces inside fields.
.SH "SEE ALSO"
cnt(1), ev(1), getinfo(1), icalc(1), rcollate(1), rlam(1),
rsplit(1), tabfunc(1), total(1)
Revision:	1.15
Committed:	Sat Jul 20 00:57:43 2019 UTC (4 years, 10 months ago) by greg
Branch:	MAIN
CVS Tags:	rad5R3
Changes since 1.14:	+4 -3 lines
Log Message:	Added mention of rsplit(1)
#	User	Rev	Content
1	greg	1.15	.\" RCSid "$Id: rcalc.1,v 1.14 2019/06/10 13:56:52 greg Exp $"
2	greg	1.1	.TH RCALC 1 4/6/99 RADIANCE
3			.SH NAME
4			rcalc - record calculator
5			.SH SYNOPSIS
6			.B rcalc
7			[
8			.B \-b
9			][
10			.B \-l
11			][
12	greg	1.6	.B \-p
13			][
14	greg	1.1	.B \-n
15			][
16			.B \-w
17			][
18			.B \-u
19			][
20			.B \-tS
21			][
22			.B "\-i format"
23			][
24			.B "\-o format"
25			][
26	greg	1.12	.B "\-in M"
27			][
28			.B "\-on M"
29			][
30	greg	1.1	.B "\-f source"
31			][
32			.B "\-e expr"
33			][
34			.B "\-s svar=sval"
35			]
36			file ..
37			.SH DESCRIPTION
38			.I Rcalc
39			transforms ``records'' from each
40			.I file
41			according to the given set of literal and relational information.
42			By default, records are separated by newlines, and contain
43			numeric fields separated by tabs.
44			The
45			.I \-tS
46			option is used to specify an alternate tab character.
47	greg	1.2	.PP
48	greg	1.1	A
49			.I \-i format
50			option specifies a template for an alternate
51			input record format.
52			.I Format
53			is interpreted as a specification string if it contains a dollar sign '$'.
54			Otherwise, it is interpreted as the name of the file containing
55			the format specification.
56			In either case, if the format does not end with a newline, one will be added
57			automatically.
58	greg	1.2	A special form of the
59			.I \-i
60			option may be followed immediately by a 'd' or an 'f' and an optional
61			count, which defaults to 1, indicating the number of double or float
62			binary values to read per record on the input file.
63	greg	1.7	If the input is byte-swapped, the
64			.I \-iD
65			or
66			.I \-iF
67			options may be substituted.
68	greg	1.2	If binary input is specified, no format string or file is needed.
69			.PP
70	greg	1.1	A
71			.I \-o format
72			option specifies an alternate output record format.
73	greg	1.2	It is interpreted the same as an input specification, except that
74			the special
75			.I \-od
76			or
77			.I \-of
78			options do not require a count, as this will be determined by the
79			number of output channels in the given expressions.
80	greg	1.7	If byte-swapped output is desired, the
81			.I \-oD
82			or
83			.I \-oF
84			options may be substituted.
85	greg	1.2	.PP
86	greg	1.6	The
87			.I \-p
88			option specifies "passive mode," where characters that do not
89			match the input format are passed unaltered to the output.
90			This option has no effect unless
91			.I \-i
92			is also specified, and does not make much sense unless
93			.I \-o
94			is also given.
95			With both input and output formats, the passive mode can
96			effectively substitute information in the middle of a file
97			or stream without affecting the rest of the data.
98			.PP
99	greg	1.12	If a
100			.I \-in
101			option is given with a positive integer argument,
102			.I rcalc
103			will stop processing input once it has loaded this number of records.
104			Similarly, if a
105			.I \-on
106			option is present,
107			.I rcalc
108			will stop after producing this many records, which may be a smaller
109			number if the
110			.I cond
111			variable is used.
112			If multiple input files are given, these counts are continuous over
113			the input and do not reset on each file.
114			.PP
115	greg	1.1	The variable and function definitions in each
116			.I \-f source
117	greg	1.11	file are read and compiled from the RADIANCE library where it is found.
118	greg	1.1	The
119			.I \-e expr
120			option can be used to define variables on the command line.
121			Since many of the characters in an expression have special meaning
122			to the shell, it should usually be enclosed in single quotes.
123			The
124			.I \-s svar=sval
125			option can be used to assign a string variable a string value.
126			If this string variable appears in an input format, only records
127			with the specified value will be processed.
128	greg	1.2	.PP
129	greg	1.1	The
130			.I \-b
131			option instructs the program to accept only exact matches.
132			By default, tabs and spaces are ignored except
133			as field separators.
134			The
135			.I \-l
136			option instructs the program to ignore newlines in the input,
137			basically treating them the same as tabs and spaces.
138			Normally, the beginning of the input format matches the beginning of
139			a line, and the end of the format matches the end of a line.
140			With the
141			.I \-l
142			option, the input format can match anywhere on a line.
143	greg	1.2	.PP
144	greg	1.1	The
145			.I \-w
146			option causes non-fatal error messages (such as division by zero) to
147			be supressed.
148			The
149			.I \-u
150			option causes output to be flushed after each record.
151			The
152			.I \-n
153			option tells the program not to get any input, but to produce a
154			single output record.
155			Otherwise, if no files are given, the standard input is read.
156			.PP
157			Format files associate names with string and numeric fields
158			separated by literal information in a record.
159			A numeric field is given in a format file as a dollar sign, followed
160			by curly braces enclosing a variable name:
161			.PP
162			This is a numeric field: ${vname}
163			.PP
164			A string variable is enclosed in parentheses:
165			.PP
166			This is a string field: $(sname)
167			.PP
168			The program attempts to match literal information in
169			the input format to its input and assign string and numeric
170			fields accordingly.
171			If a string or numeric field variable appears more than once in
172			the input format, input values for the corresponding fields must
173			match (ie. have the same value) for the whole record to match.
174			Numeric values are allowed some deviation, on the order of 0.1%, but
175			string variables must match exactly.
176			Thus, dummy variables for "don't care" fields should be given unique
177			names so that they are not all required to take on the same value.
178			.PP
179			For each valid input record, an output record is produced
180			in its corresponding format.
181			Output field widths are given implicitly by the space occupied
182			in the format file, including the dollar sign and braces.
183			This makes it impossible to produce fields with fewer than four
184			characters.
185			If the
186			.I \-b
187			option is specified, input records must exactly match the
188			template.
189			By default, the character following each input field is used as
190			a delimiter.
191			This implies that string fields that are followed by white space
192			cannot contain strings with white space.
193			Also, numeric fields followed but not preceded by white space
194			will not accept numbers preceded by white space.
195			Adjacent input fields are advisable only with the
196			.I \-b
197			option.
198			Numeric output fields may contain expressions as well as variables.
199			A dollar sign may appear in a literal as two dollar signs ($$).
200			.PP
201			The definitions specified in
202			.I \-e
203			and
204			.I \-f
205			options relate numeric output fields to numeric input fields.
206			For the default record format, a field is a variable of the form
207			$N, where N is the column number, beginning with 1.
208			Output columns appear on the left-hand side of assignments, input
209			columns appear on the right-hand side.
210			.PP
211			A variable definition has the form:
212			.PP
213
214			var = expression ;
215
216			.PP
217			Any instance of the variable in an expression will be replaced
218			with its definition.
219			.PP
220			An expression contains real numbers, variable names, function calls,
221			and the following operators:
222			.PP
223			+ - * / ^
224			.PP
225	greg	1.9	Operators are evaluated left to right, except '^',
226			which is right associative.
227	greg	1.1	Powers have the highest precedence; multiplication and
228			division are evaluated before addition and subtraction.
229			Expressions can be grouped with parentheses.
230			All values are double precision real.
231			.PP
232			A function definition has the form:
233			.PP
234
235			func(a1, a2, ..) = expression ;
236
237			.PP
238			The expression can contain instances of the function arguments
239			as well as other variables and functions.
240			Function names can be passed as arguments.
241			Recursive functions can be defined using calls to the defined
242			function or other functions calling the defined function.
243			.PP
244			The variable
245			.I cond,
246			if defined, will determine whether the current input record produces
247			an output record.
248			If
249			.I cond
250			is positive, output is produced.
251			If
252			.I cond
253			is less than or equal to zero, the record is skipped and no other expressions
254			are evaluated.
255			This provides a convenient method for avoiding inappropriate calculations.
256			The following library of pre-defined functions and variables is provided:
257			.TP 10n
258	greg	1.13	.BR $N
259	greg	1.9	Return the value for input column
260			.I N.
261			If an input format is given, using a channel number generates an error.
262			.TP
263	greg	1.3	.BR "in(n)"
264			Return the value for input column
265			.I n,
266			or the number of columns available in this record if
267			.I n
268			is 0.
269			This is an alternate way to get a column value instead of using
270			the $N notation, and is more flexible since it is programmable.
271			This function is disabled if an input format is used.
272			.TP
273	greg	1.1	.BR "if(cond, then, else)"
274			if cond is greater than zero,
275			then is evaluated, otherwise else is evaluated.
276			This function is necessary for recursive definitions.
277			.TP
278			.BR "select(N, a1, a2, ..)"
279			return aN (N is rounded to the nearest integer).
280			This function provides array capabilities.
281			If
282			.I N
283			is zero, the number of available arguments is returned.
284			.TP
285			.BR "rand(x)"
286			compute a random number between 0 and 1 based on x.
287			.TP
288	greg	1.14	.BR "min(a1, a2, ..)"
289			return the minimum value from a list of arguments.
290			.TP
291			.BR "max(a1, a2, ..)"
292			return the maximum value from a list of arguments.
293			.TP
294	greg	1.1	.BR "floor(x)"
295			return largest integer not greater than x.
296			.TP
297			.BR "ceil(x)"
298			return smallest integer not less than x.
299			.TP
300			.BR "sqrt(x)"
301			return square root of x.
302			.TP
303			.BR "exp(x)"
304			compute e to the power of x (e approx = 2.718281828).
305			.TP
306			.BR "log(x)"
307			compute the logarithm of x to the base e.
308			.TP
309			.BR "log10(x)"
310			compute the logarithm of x to the base 10.
311			.TP
312			.BR PI
313			the ratio of a circle's circumference to its diameter.
314			.TP
315			.BR recno
316			the number of records recognized thus far.
317			.TP
318			.BR outno
319			the number or records output thus far (including this one).
320			.TP
321			.BR "sin(x), cos(x), tan(x)"
322			trigonometric functions.
323			.TP
324			.BR "asin(x), acos(x), atan(x)"
325			inverse trigonometric functions.
326			.TP
327			.BR "atan2(y, x)"
328	greg	1.8	inverse tangent of y/x (range \-pi to pi).
329	greg	1.1	.SH EXAMPLE
330			To print the square root of column two in column one,
331			and column one times column three in column two:
332			.IP "" .2i
333	greg	1.15	rcalc -e '$1=sqrt($2);$2=$1*$3' inputfile > outputfile
334	greg	1.11	.SH ENVIRONMENT
335			RAYPATH the directories to check for auxiliary files.
336	greg	1.1	.SH AUTHOR
337			Greg Ward
338			.SH BUGS
339			String variables can only be used in input and output formats and
340			.I \-s
341			options, not in definitions.
342			.PP
343			Tabs count as single spaces inside fields.
344			.SH "SEE ALSO"
345	greg	1.15	cnt(1), ev(1), getinfo(1), icalc(1), rcollate(1), rlam(1),
346			rsplit(1), tabfunc(1), total(1)