man/man1/rcalc.1

.\" RCSid "$Id: rcalc.1,v 1.7 2006/12/23 17:27:45 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 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
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*$3' inputfile > outputfile
.SH AUTHOR
Greg Ward
.SH BUGS
String variables can only be used in input and output formats and
.I \-s
options, not in definitions.
.PP
Tabs count as single spaces inside fields.
.SH "SEE ALSO"
cnt(1), ev(1), getinfo(1), icalc(1), rlam(1), tabfunc(1), total(1)
Revision:	1.8
Committed:	Tue Sep 4 17:36:41 2007 UTC (16 years, 8 months ago) by greg
Branch:	MAIN
CVS Tags:	rad4R1, rad4R0, rad3R9
Changes since 1.7:	+3 -3 lines
Log Message:	Added backslashes in front of hyphens (thanks to Bernd Zeimetz for his effort)
#	Content
1	.\" RCSid "$Id: rcalc.1,v 1.7 2006/12/23 17:27:45 greg Exp $"
2	.TH RCALC 1 4/6/99 RADIANCE
3	.SH NAME
4	rcalc - record calculator
5	.SH SYNOPSIS
6	.B rcalc
7	[
8	.B \-b
9	][
10	.B \-l
11	][
12	.B \-p
13	][
14	.B \-n
15	][
16	.B \-w
17	][
18	.B \-u
19	][
20	.B \-tS
21	][
22	.B "\-i format"
23	][
24	.B "\-o format"
25	][
26	.B "\-f source"
27	][
28	.B "\-e expr"
29	][
30	.B "\-s svar=sval"
31	]
32	file ..
33	.SH DESCRIPTION
34	.I Rcalc
35	transforms ``records'' from each
36	.I file
37	according to the given set of literal and relational information.
38	By default, records are separated by newlines, and contain
39	numeric fields separated by tabs.
40	The
41	.I \-tS
42	option is used to specify an alternate tab character.
43	.PP
44	A
45	.I \-i format
46	option specifies a template for an alternate
47	input record format.
48	.I Format
49	is interpreted as a specification string if it contains a dollar sign '$'.
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	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 the input is byte-swapped, the
60	.I \-iD
61	or
62	.I \-iF
63	options may be substituted.
64	If binary input is specified, no format string or file is needed.
65	.PP
66	A
67	.I \-o format
68	option specifies an alternate output record format.
69	It is interpreted the same as an input specification, except that
70	the special
71	.I \-od
72	or
73	.I \-of
74	options do not require a count, as this will be determined by the
75	number of output channels in the given expressions.
76	If byte-swapped output is desired, the
77	.I \-oD
78	or
79	.I \-oF
80	options may be substituted.
81	.PP
82	The
83	.I \-p
84	option specifies "passive mode," where characters that do not
85	match the input format are passed unaltered to the output.
86	This option has no effect unless
87	.I \-i
88	is also specified, and does not make much sense unless
89	.I \-o
90	is also given.
91	With both input and output formats, the passive mode can
92	effectively substitute information in the middle of a file
93	or stream without affecting the rest of the data.
94	.PP
95	The variable and function definitions in each
96	.I \-f source
97	file are read and compiled.
98	The
99	.I \-e expr
100	option can be used to define variables on the command line.
101	Since many of the characters in an expression have special meaning
102	to the shell, it should usually be enclosed in single quotes.
103	The
104	.I \-s svar=sval
105	option can be used to assign a string variable a string value.
106	If this string variable appears in an input format, only records
107	with the specified value will be processed.
108	.PP
109	The
110	.I \-b
111	option instructs the program to accept only exact matches.
112	By default, tabs and spaces are ignored except
113	as field separators.
114	The
115	.I \-l
116	option instructs the program to ignore newlines in the input,
117	basically treating them the same as tabs and spaces.
118	Normally, the beginning of the input format matches the beginning of
119	a line, and the end of the format matches the end of a line.
120	With the
121	.I \-l
122	option, the input format can match anywhere on a line.
123	.PP
124	The
125	.I \-w
126	option causes non-fatal error messages (such as division by zero) to
127	be supressed.
128	The
129	.I \-u
130	option causes output to be flushed after each record.
131	The
132	.I \-n
133	option tells the program not to get any input, but to produce a
134	single output record.
135	Otherwise, if no files are given, the standard input is read.
136	.PP
137	Format files associate names with string and numeric fields
138	separated by literal information in a record.
139	A numeric field is given in a format file as a dollar sign, followed
140	by curly braces enclosing a variable name:
141	.PP
142	This is a numeric field: ${vname}
143	.PP
144	A string variable is enclosed in parentheses:
145	.PP
146	This is a string field: $(sname)
147	.PP
148	The program attempts to match literal information in
149	the input format to its input and assign string and numeric
150	fields accordingly.
151	If a string or numeric field variable appears more than once in
152	the input format, input values for the corresponding fields must
153	match (ie. have the same value) for the whole record to match.
154	Numeric values are allowed some deviation, on the order of 0.1%, but
155	string variables must match exactly.
156	Thus, dummy variables for "don't care" fields should be given unique
157	names so that they are not all required to take on the same value.
158	.PP
159	For each valid input record, an output record is produced
160	in its corresponding format.
161	Output field widths are given implicitly by the space occupied
162	in the format file, including the dollar sign and braces.
163	This makes it impossible to produce fields with fewer than four
164	characters.
165	If the
166	.I \-b
167	option is specified, input records must exactly match the
168	template.
169	By default, the character following each input field is used as
170	a delimiter.
171	This implies that string fields that are followed by white space
172	cannot contain strings with white space.
173	Also, numeric fields followed but not preceded by white space
174	will not accept numbers preceded by white space.
175	Adjacent input fields are advisable only with the
176	.I \-b
177	option.
178	Numeric output fields may contain expressions as well as variables.
179	A dollar sign may appear in a literal as two dollar signs ($$).
180	.PP
181	The definitions specified in
182	.I \-e
183	and
184	.I \-f
185	options relate numeric output fields to numeric input fields.
186	For the default record format, a field is a variable of the form
187	$N, where N is the column number, beginning with 1.
188	Output columns appear on the left-hand side of assignments, input
189	columns appear on the right-hand side.
190	.PP
191	A variable definition has the form:
192	.PP
193
194	var = expression ;
195
196	.PP
197	Any instance of the variable in an expression will be replaced
198	with its definition.
199	.PP
200	An expression contains real numbers, variable names, function calls,
201	and the following operators:
202	.PP
203	+ - * / ^
204	.PP
205	Operators are evaluated left to right.
206	Powers have the highest precedence; multiplication and
207	division are evaluated before addition and subtraction.
208	Expressions can be grouped with parentheses.
209	All values are double precision real.
210	.PP
211	A function definition has the form:
212	.PP
213
214	func(a1, a2, ..) = expression ;
215
216	.PP
217	The expression can contain instances of the function arguments
218	as well as other variables and functions.
219	Function names can be passed as arguments.
220	Recursive functions can be defined using calls to the defined
221	function or other functions calling the defined function.
222	.PP
223	The variable
224	.I cond,
225	if defined, will determine whether the current input record produces
226	an output record.
227	If
228	.I cond
229	is positive, output is produced.
230	If
231	.I cond
232	is less than or equal to zero, the record is skipped and no other expressions
233	are evaluated.
234	This provides a convenient method for avoiding inappropriate calculations.
235	The following library of pre-defined functions and variables is provided:
236	.TP 10n
237	.BR "in(n)"
238	Return the value for input column
239	.I n,
240	or the number of columns available in this record if
241	.I n
242	is 0.
243	This is an alternate way to get a column value instead of using
244	the $N notation, and is more flexible since it is programmable.
245	This function is disabled if an input format is used.
246	.TP
247	.BR "if(cond, then, else)"
248	if cond is greater than zero,
249	then is evaluated, otherwise else is evaluated.
250	This function is necessary for recursive definitions.
251	.TP
252	.BR "select(N, a1, a2, ..)"
253	return aN (N is rounded to the nearest integer).
254	This function provides array capabilities.
255	If
256	.I N
257	is zero, the number of available arguments is returned.
258	.TP
259	.BR "rand(x)"
260	compute a random number between 0 and 1 based on x.
261	.TP
262	.BR "floor(x)"
263	return largest integer not greater than x.
264	.TP
265	.BR "ceil(x)"
266	return smallest integer not less than x.
267	.TP
268	.BR "sqrt(x)"
269	return square root of x.
270	.TP
271	.BR "exp(x)"
272	compute e to the power of x (e approx = 2.718281828).
273	.TP
274	.BR "log(x)"
275	compute the logarithm of x to the base e.
276	.TP
277	.BR "log10(x)"
278	compute the logarithm of x to the base 10.
279	.TP
280	.BR PI
281	the ratio of a circle's circumference to its diameter.
282	.TP
283	.BR recno
284	the number of records recognized thus far.
285	.TP
286	.BR outno
287	the number or records output thus far (including this one).
288	.TP
289	.BR "sin(x), cos(x), tan(x)"
290	trigonometric functions.
291	.TP
292	.BR "asin(x), acos(x), atan(x)"
293	inverse trigonometric functions.
294	.TP
295	.BR "atan2(y, x)"
296	inverse tangent of y/x (range \-pi to pi).
297	.SH EXAMPLE
298	To print the square root of column two in column one,
299	and column one times column three in column two:
300	.IP "" .2i
301	rcalc \-e '$1=sqrt($2);$2=$1*$3' inputfile > outputfile
302	.SH AUTHOR
303	Greg Ward
304	.SH BUGS
305	String variables can only be used in input and output formats and
306	.I \-s
307	options, not in definitions.
308	.PP
309	Tabs count as single spaces inside fields.
310	.SH "SEE ALSO"
311	cnt(1), ev(1), getinfo(1), icalc(1), rlam(1), tabfunc(1), total(1)