man/man1/rcalc.1

.\" RCSid "$Id: rcalc.1,v 1.5 2004/01/01 19:31:45 greg Exp $"
.TH RCALC 1 4/6/99 RADIANCE
.SH NAME
rcalc - record calculator
.SH SYNOPSIS
.B rcalc
[
.B \-b
][
.B \-l
][
.B \-p
][
.B \-n
][
.B \-w
][
.B \-u
][
.B \-tS
][
.B "\-i format"
][
.B "\-o format"
][
.B "\-f source"
][
.B "\-e expr"
][
.B "\-s svar=sval"
]
file ..
.SH DESCRIPTION
.I Rcalc
transforms ``records'' from each
.I file
according to the given set of literal and relational information.
By default, records are separated by newlines, and contain
numeric fields separated by tabs.
The
.I \-tS
option is used to specify an alternate tab character.
.PP
A
.I \-i format
option specifies a template for an alternate
input record format.
.I Format
is interpreted as a specification string if it contains a dollar sign '$'.
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 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.
.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
The variable and function definitions in each
.I \-f source
file are read and compiled.
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.
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 "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 "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*$3' inputfile > outputfile
.SH AUTHOR
Greg Ward
.SH BUGS
String variables can only be used in input and output formats and
.I \-s
options, not in definitions.
.PP
Tabs count as single spaces inside fields.
.SH "SEE ALSO"
cnt(1), ev(1), getinfo(1), icalc(1), rlam(1), tabfunc(1), total(1)
Revision:	1.6
Committed:	Wed Jun 9 16:00:12 2004 UTC (21 years, 4 months ago) by greg
Branch:	MAIN
CVS Tags:	rad3R7P2, rad3R7P1, rad3R6, rad3R6P1, rad3R8
Changes since 1.5:	+16 -1 lines
Log Message:	Added -p option to rcalc for new passive mode
#	User	Rev	Content
1	greg	1.6	.\" RCSid "$Id: rcalc.1,v 1.5 2004/01/01 19:31:45 greg Exp $"
2	greg	1.1	.TH RCALC 1 4/6/99 RADIANCE
3			.SH NAME
4			rcalc - record calculator
5			.SH SYNOPSIS
6			.B rcalc
7			[
8			.B \-b
9			][
10			.B \-l
11			][
12	greg	1.6	.B \-p
13			][
14	greg	1.1	.B \-n
15			][
16			.B \-w
17			][
18			.B \-u
19			][
20			.B \-tS
21			][
22			.B "\-i format"
23			][
24			.B "\-o format"
25			][
26			.B "\-f source"
27			][
28			.B "\-e expr"
29			][
30			.B "\-s svar=sval"
31			]
32			file ..
33			.SH DESCRIPTION
34			.I Rcalc
35			transforms ``records'' from each
36			.I file
37			according to the given set of literal and relational information.
38			By default, records are separated by newlines, and contain
39			numeric fields separated by tabs.
40			The
41			.I \-tS
42			option is used to specify an alternate tab character.
43	greg	1.2	.PP
44	greg	1.1	A
45			.I \-i format
46			option specifies a template for an alternate
47			input record format.
48			.I Format
49			is interpreted as a specification string if it contains a dollar sign '$'.
50			Otherwise, it is interpreted as the name of the file containing
51			the format specification.
52			In either case, if the format does not end with a newline, one will be added
53			automatically.
54	greg	1.2	A special form of the
55			.I \-i
56			option may be followed immediately by a 'd' or an 'f' and an optional
57			count, which defaults to 1, indicating the number of double or float
58			binary values to read per record on the input file.
59			If binary input is specified, no format string or file is needed.
60			.PP
61	greg	1.1	A
62			.I \-o format
63			option specifies an alternate output record format.
64	greg	1.2	It is interpreted the same as an input specification, except that
65			the special
66			.I \-od
67			or
68			.I \-of
69			options do not require a count, as this will be determined by the
70			number of output channels in the given expressions.
71			.PP
72	greg	1.6	The
73			.I \-p
74			option specifies "passive mode," where characters that do not
75			match the input format are passed unaltered to the output.
76			This option has no effect unless
77			.I \-i
78			is also specified, and does not make much sense unless
79			.I \-o
80			is also given.
81			With both input and output formats, the passive mode can
82			effectively substitute information in the middle of a file
83			or stream without affecting the rest of the data.
84			.PP
85	greg	1.1	The variable and function definitions in each
86			.I \-f source
87			file are read and compiled.
88			The
89			.I \-e expr
90			option can be used to define variables on the command line.
91			Since many of the characters in an expression have special meaning
92			to the shell, it should usually be enclosed in single quotes.
93			The
94			.I \-s svar=sval
95			option can be used to assign a string variable a string value.
96			If this string variable appears in an input format, only records
97			with the specified value will be processed.
98	greg	1.2	.PP
99	greg	1.1	The
100			.I \-b
101			option instructs the program to accept only exact matches.
102			By default, tabs and spaces are ignored except
103			as field separators.
104			The
105			.I \-l
106			option instructs the program to ignore newlines in the input,
107			basically treating them the same as tabs and spaces.
108			Normally, the beginning of the input format matches the beginning of
109			a line, and the end of the format matches the end of a line.
110			With the
111			.I \-l
112			option, the input format can match anywhere on a line.
113	greg	1.2	.PP
114	greg	1.1	The
115			.I \-w
116			option causes non-fatal error messages (such as division by zero) to
117			be supressed.
118			The
119			.I \-u
120			option causes output to be flushed after each record.
121			The
122			.I \-n
123			option tells the program not to get any input, but to produce a
124			single output record.
125			Otherwise, if no files are given, the standard input is read.
126			.PP
127			Format files associate names with string and numeric fields
128			separated by literal information in a record.
129			A numeric field is given in a format file as a dollar sign, followed
130			by curly braces enclosing a variable name:
131			.PP
132			This is a numeric field: ${vname}
133			.PP
134			A string variable is enclosed in parentheses:
135			.PP
136			This is a string field: $(sname)
137			.PP
138			The program attempts to match literal information in
139			the input format to its input and assign string and numeric
140			fields accordingly.
141			If a string or numeric field variable appears more than once in
142			the input format, input values for the corresponding fields must
143			match (ie. have the same value) for the whole record to match.
144			Numeric values are allowed some deviation, on the order of 0.1%, but
145			string variables must match exactly.
146			Thus, dummy variables for "don't care" fields should be given unique
147			names so that they are not all required to take on the same value.
148			.PP
149			For each valid input record, an output record is produced
150			in its corresponding format.
151			Output field widths are given implicitly by the space occupied
152			in the format file, including the dollar sign and braces.
153			This makes it impossible to produce fields with fewer than four
154			characters.
155			If the
156			.I \-b
157			option is specified, input records must exactly match the
158			template.
159			By default, the character following each input field is used as
160			a delimiter.
161			This implies that string fields that are followed by white space
162			cannot contain strings with white space.
163			Also, numeric fields followed but not preceded by white space
164			will not accept numbers preceded by white space.
165			Adjacent input fields are advisable only with the
166			.I \-b
167			option.
168			Numeric output fields may contain expressions as well as variables.
169			A dollar sign may appear in a literal as two dollar signs ($$).
170			.PP
171			The definitions specified in
172			.I \-e
173			and
174			.I \-f
175			options relate numeric output fields to numeric input fields.
176			For the default record format, a field is a variable of the form
177			$N, where N is the column number, beginning with 1.
178			Output columns appear on the left-hand side of assignments, input
179			columns appear on the right-hand side.
180			.PP
181			A variable definition has the form:
182			.PP
183
184			var = expression ;
185
186			.PP
187			Any instance of the variable in an expression will be replaced
188			with its definition.
189			.PP
190			An expression contains real numbers, variable names, function calls,
191			and the following operators:
192			.PP
193			+ - * / ^
194			.PP
195			Operators are evaluated left to right.
196			Powers have the highest precedence; multiplication and
197			division are evaluated before addition and subtraction.
198			Expressions can be grouped with parentheses.
199			All values are double precision real.
200			.PP
201			A function definition has the form:
202			.PP
203
204			func(a1, a2, ..) = expression ;
205
206			.PP
207			The expression can contain instances of the function arguments
208			as well as other variables and functions.
209			Function names can be passed as arguments.
210			Recursive functions can be defined using calls to the defined
211			function or other functions calling the defined function.
212			.PP
213			The variable
214			.I cond,
215			if defined, will determine whether the current input record produces
216			an output record.
217			If
218			.I cond
219			is positive, output is produced.
220			If
221			.I cond
222			is less than or equal to zero, the record is skipped and no other expressions
223			are evaluated.
224			This provides a convenient method for avoiding inappropriate calculations.
225			The following library of pre-defined functions and variables is provided:
226			.TP 10n
227	greg	1.3	.BR "in(n)"
228			Return the value for input column
229			.I n,
230			or the number of columns available in this record if
231			.I n
232			is 0.
233			This is an alternate way to get a column value instead of using
234			the $N notation, and is more flexible since it is programmable.
235			This function is disabled if an input format is used.
236			.TP
237	greg	1.1	.BR "if(cond, then, else)"
238			if cond is greater than zero,
239			then is evaluated, otherwise else is evaluated.
240			This function is necessary for recursive definitions.
241			.TP
242			.BR "select(N, a1, a2, ..)"
243			return aN (N is rounded to the nearest integer).
244			This function provides array capabilities.
245			If
246			.I N
247			is zero, the number of available arguments is returned.
248			.TP
249			.BR "rand(x)"
250			compute a random number between 0 and 1 based on x.
251			.TP
252			.BR "floor(x)"
253			return largest integer not greater than x.
254			.TP
255			.BR "ceil(x)"
256			return smallest integer not less than x.
257			.TP
258			.BR "sqrt(x)"
259			return square root of x.
260			.TP
261			.BR "exp(x)"
262			compute e to the power of x (e approx = 2.718281828).
263			.TP
264			.BR "log(x)"
265			compute the logarithm of x to the base e.
266			.TP
267			.BR "log10(x)"
268			compute the logarithm of x to the base 10.
269			.TP
270			.BR PI
271			the ratio of a circle's circumference to its diameter.
272			.TP
273			.BR recno
274			the number of records recognized thus far.
275			.TP
276			.BR outno
277			the number or records output thus far (including this one).
278			.TP
279			.BR "sin(x), cos(x), tan(x)"
280			trigonometric functions.
281			.TP
282			.BR "asin(x), acos(x), atan(x)"
283			inverse trigonometric functions.
284			.TP
285			.BR "atan2(y, x)"
286			inverse tangent of y/x (range -pi to pi).
287			.SH EXAMPLE
288			To print the square root of column two in column one,
289			and column one times column three in column two:
290			.IP "" .2i
291			rcalc -e '$1=sqrt($2);$2=$1*$3' inputfile > outputfile
292			.SH AUTHOR
293			Greg Ward
294			.SH BUGS
295			String variables can only be used in input and output formats and
296			.I \-s
297			options, not in definitions.
298			.PP
299			Tabs count as single spaces inside fields.
300			.SH "SEE ALSO"
301	greg	1.5	cnt(1), ev(1), getinfo(1), icalc(1), rlam(1), tabfunc(1), total(1)