This document contains a summary of the options for processing column-based text files.
Funtools will automatically sense and process "standard" column-based text files as if they were FITS binary tables without any change in Funtools syntax. In particular, you can filter text files using the same syntax as FITS binary tables:
fundisp foo'[cir 512 512 .1]' fundisp -T foo funtable foo'[pha=1:10,cir 512 512 10]' foo.fits
The first example displays a filtered selection of a text file. The second example converts a text file to an RDB file. The third example converts a filtered selection of a text file to a FITS binary table.
Text files can also be used in Funtools image programs. In this case, you must provide binning parameters (as with raw event files), using the bincols keyword specifier:
bincols=([xname[:tlmin[:tlmax:[binsiz]]]],[yname[:tlmin[:tlmax[:binsiz]]]For example:
funcnts foo'[bincols=(x:1024,y:1024)]' "ann 512 512 0 10 n=10"
Standard text files have the following characteristics:
Examples:
# rdb file foo1 foo2 foo3 foos ---- ---- ---- ---- 1 2.2 3 xxxx 10 20.2 30 yyyy # multiple consecutive whitespace and dashes foo1 foo2 foo3 foos --- ---- ---- ---- 1 2.2 3 xxxx 10 20.2 30 yyyy # comma delims and blank lines foo1,foo2,foo3,foos 1,2.2,3,xxxx 10,20.2,30,yyyy # bar delims with null values foo1|foo2|foo3|foos 1||3|xxxx 10|20.2||yyyy # header-less data 1 2.2 3 xxxx 10 20.2 30 yyyy
The default set of token delimiters consists of spaces, tabs, commas, semi-colons, and vertical bars. Several parsers are tried simultaneously to analyze a line of text in different ways. One way of analyzing a line is to allow a combination of spaces, tabs, and commas to be squashed into a single delimiter (no null values between consecutive delimiters). Another way is to allow tab, semi-colon, and vertical bar delimiters to support null values, i.e. two consecutive delimiters implies a null value (e.g. RDB file). A successful parser is one which returns a consistent number of columns for all rows, with each column having a consistent data type. More than one parser can be successful. For now, it is assumed that they return the same tokens for a given line (theoretically, there are pathological cases, to be taken care of later on, maybe). Bad parsers are discarded on the fly.
If the header does not exist, then names "col1", "col2", etc. are assigned to the columns to allow filtering. Furthermore, data types for each column are determined by the data types found in the columns of the first data line and can be one of the following: string, int, and double. Thus, all of the above examples return the following display:
fundisp foo'[foo1>5]' FOO1 FOO2 FOO3 FOOS ---------- --------------------- ---------- ------------ 10 20.20000000 30 yyyy
Comments which precede data rows are converted into header parameters and will be written out as such using funimage or funhead. Two styles of comments are recognized:
1. FITS-style comments have an equal sign "=" between the keyword and value and an optional slash "/" to signify a comment. The strict FITS rules on column positions are not enforced. In addition, strings only need to be quoted if they contain whitespace. For example, the following are valid FITS-style comments:
# fits0 = 100 # fits1 = /usr/local/bin # fits2 = "/usr/local/bin /opt/local/bin" # fits3c = /usr/local/bin /opt/local/bin /usr/bin # fits4c = "/usr/local/bin /opt/local/bin" / path dirNote that the fits3c comment is not quoted and therefore its value is the single token "/usr/local/bin" and the comment is "opt/local/bin /usr/bin". This different from the quoted comment in fits4c.
2. Free-form comments can have an optional colon separator between the keyword and value. In the absence of quote, all tokens after the keyword are part of the value, i.e. no comment is allowed. If a string is quoted, then slash "/" after the string will signify a comment. For example:
# foo1 /usr/local/bin # foo2 "/usr/local/bin /opt/local/bin" # foo3 /usr/local/bin /opt/local/bin /usr/bin # foo4c "/usr/local/bin /opt/local/bin" / path dir # goo1: /usr/local/bin # goo2: "/usr/local/bin /opt/local/bin" # goo3: /usr/local/bin /opt/local/bin /usr/bin # goo4c: "/usr/local/bin /opt/local/bin" / path dir
Note that foo3 and goo3 are not quoted, so the whole string is part of the value, while foo4c and goo4c are quoted and have comments following the values.
Multiple tables are supported in a single file. If an RDB-style file is sensed, then a ^L will signify end of table. Otherwise, an end of table is sensed when a new header (i.e., all alphanumeric columns) is found. Also, for standard parsers, end of table is sensed when a comment is found, i.e. comments are not mixed with data rows (although blank lines can be mixed).
You can access the nth table (starting from 0) in a multi-table file by enclosing the table number in brackets, as with a FITS extension:
fundisp foo'[2]'The above example will display the third table in the file.
As with ARRAY() and EVENTS() specifiers for raw image arrays and raw event lists respectively, you can use the TEXT() on text files to pass key=value options to the parsers. An empty set of keywords is equivalent to not having TEXT() at all, that is:
fundisp foo fundisp foo'[TEXT()]'are equivalent. A multi-table index number is placed inside the TEXT() specifier as the first token, when indexing into a multi-table: fundisp foo'[TEXT(2,...)]'
The filter specification is placed after the TEXT() specifier, separated by a comma, or in an entirely separate bracket:
fundisp foo'[TEXT(...),circle 512 512 .1]' fundisp foo'[TEXT(2,...)][circle 512 512 .1]'
The following is a list of keywords that can be used within the TEXT() specifier (the first three are the most important ones):
fundisp foo.fits'[TEXT(delims="!")]' fundisp foo.fits'[TEXT(delims="\t%")]'
fundisp foo.fits'[TEXT(comchars="!\n")]'
fundisp foo.fits'[TEXT(cols="x:I,y:I,pha:I,pi:I,time:D,dx:E,dy:e")]'
If the column specifier is the only keyword, then the cols= is not required (in analogy with EVENTS()):
fundisp foo.fits'[TEXT(x:I,y:I,pha:I,pi:I,time:D,dx:E,dy:e)]'A index is allowed in this case:
fundisp foo.fits'[TEXT(2,x:I,y:I,pha:I,pi:I,time:D,dx:E,dy:e)]'
fundisp foo.fits'[TEXT(eot="END")]'will end the table when a line contains "END" is found. Multiple lines are supported, so that:
fundisp foo.fits'[TEXT(eot="END\nGAME")]'will end the table when a line contains "END" followed by a line containing "GAME".
In the absence of an EOT delimiter, a new table will be sensed when a new header (all alphanumeric columns) is found.
Environment variables are defined to allow many of these values to be set without having to include them in TEXT() every time a file is processed:
keyword environment variable ------- -------------------- delims TEXT_DELIMS comchars TEXT_COMCHARS cols TEXT_COLUMNS eot TEXT_EOT null1 TEXT_NULL1 alen TEXT_ALEN bincols TEXT_BINCOLS
As with raw event files, the '+' (copy extensions) specifier is not supported for programs such as funtable.