Manpages

Misc

NAME

DESCRIPTION

SYNOPSIS

 use PDL::IO::Misc;

FUNCTIONS

rfits()

  $pdl = rfits('file.fits');

  # Automatically uncompress via gunzip pipe
  $pdl = rfits('file.fits.gz');
  # Automatically uncompress via uncompress pipe
  $pdl = rfits('file.fits.Z');

  $pdl = rfits('file.fits[2]'); # Read HDU extension #2
  $pdl = rfits('file.fits.gz[3]'); # Read HDU extension #3

FITS Headers stored in piddle and can be retrived with $a->gethdr. The hdrcpy flag of the piddle is set so that the header is copied to new piddles.

This header is a reference to a hash where the hash keys are the keywords in the FITS header. It is important to note that for strings, the surrounding quotes are kept to ensure that strings that look like numbers are kept as strings. This is also of importance if you create your own header information and you want the value to be printed out as a string. Each record (comprising keyword, value, and any comment string) must fit within 80 characters; any value that is too long is truncated (silently). Also, keywords are converted to uppercase; this is part of the FITS standard.

Comments in headers are stored as $$h{COMMENT}{<Keyword>} where $h is the header retrieved with "$a->gethdr". History entries in the header are stored as $$h{HISTORY}, which is an anonymous array for each HISTORY entry in the header.  

wfits()

  wfits $pdl, 'filename.fits', [$BITPIX];
  $pdl->wfits('foo.fits',-32);

  # Automatically compress through pipe to gzip
  wfits $pdl, 'filename.fits.gz';
  # Automatically compress through pipe to compress 
  wfits $pdl, 'filename.fits.Z';

rcols()

There are two calling conventions - the old version, where a pattern can be specified after the filename/handle, and the new version where options are given as as hash reference. This reference can be given as either the second or last argument.

The default behaviour is to ignore lines beginning with a # character and lines that only consist of whitespace. Options exist to only read from lines that match, or do not match, supplied patterns, and to set the types of the created piddles.

Can take file name or *HANDLE, and if no columns are specified, all are assumed. For the allowed types, see ``Datatype_conversions'' in PDL::Core.

Options:

EXCLUDE or IGNORE - ignore lines matching this pattern (default '/^#/').

INCLUDE or KEEP - only use lines which match this pattern (default '').

LINES - which line numbers to use. Line numbers start at 0 and the syntax is 'a:b:c' to use every c'th matching line between a and b (default '').

DEFTYPE - default data type for stored data (if not specified, use the type stored in $PDL::IO::Misc::deftype, which starts off as double).

TYPES - reference to an array of data types, one element for each column to be read in. Any missing columns use the DEFTYPE value (default []).

PERLCOLS - an array of column numbers which are to be read into perl arrays rather than piddles. References to these arrays are returned after the requested piddles (default undef).

  Usage:
    ($x,$y,...) = rcols( *HANDLE|"filename", { EXCLUDE => '/^!/' }, 
                         $col1, $col2, ... )
    ($x,$y,...) = rcols( *HANDLE|"filename", $col1, $col2, ..., 
                         { EXCLUDE => '/^!/' } )
    ($x,$y,...) = rcols( *HANDLE|"filename", "/foo/", $col1, $col2, ... )

  $x      = PDL->rcols 'file1';
  ($x,$y) = rcols *STDOUT;

  # read in lines containing the string foo, where the first
  # example also ignores lines that with a # character.
  ($x,$y,$z) = rcols 'file2', 0,4,5, { INCLUDE => '/foo/' };
  ($x,$y,$z) = rcols 'file2', 0,4,5, 
                 { INCLUDE => '/foo/', EXCLUDE => '' };

  # ignore the first 27 lines of the file, reading in as ushort's
  ($x,$y) = rcols 'file3', { LINES => '27:-1', DEFTYPE => ushort };
  ($x,$y) = rcols 'file3', 
              { LINES => '27:', TYPES => [ ushort, ushort ] };

  # read in the first column as a perl array and the next two as piddles
  ($x,$y,$name) = rcols 'file4', 1, 2, { PERLCOLS => [ 0 ] };
  printf "Number of names read in = %d\n", 1 + $#$name;

1. Quotes are required on patterns.

2. Columns are separated by whitespace by default, use $PDL::IO::Misc::colsep to specify an alternate separator.

3. For PDL-2.003, the meaning of the 'c' value in the LINES option has changed: it now only counts matching lines rather than all lines as in previous versions of PDL.

4. LINES => '-1:0:3' may not work as you expect, since lines are skipped when read in, then the whole array reversed.  

wcols()

If no columns are specified all are assumed. Will optionally only process lines matching a pattern. Can take file name or *HANDLE, and if no file/filehandle is given defaults to STDOUT.

Options:

HEADER - prints this string before the data. If the string is not terminated by a newline, one is added (default '').

 Usage: wcols $piddle1, $piddle2,..., *HANDLE|"outfile", [\%options];

  wcols $x, $y+2, 'foo.dat';
  wcols $x, $y+2, *STDERR;
  wcols $x, $y+2, '|wc';
  wcols $a,$b,$c; # Orthogonal version of 'print $a,$b,$c' :-)

  wcols "%10.3f", $a,$b; # Formatted
  wcols "%10.3f %10.5g", $a,$b; # Individual column formatting

  wcols $a,$b, { HEADER => "#   a   b" };

swcols()

"swcols" takes an (optional) format specifier of the printf sort and a list of 1d piddles as input. It returns a perl array (or array reference if called in scalar context) where each element of the array is the string generated by printing the corresponding element of the piddle(s) using the format specified. If no format is specified it uses the default print format.

 Usage: @str = swcols format, pdl1,pdl2,pdl3,...;
  or
        $str = swcols format, pdl1,pdl2,pdl3,...;

rgrep()

Usage

 ($x,$y,...) = rgrep(sub, *HANDLE|"filename")

 ($a,$b) = rgrep {/Foo (.*) Bar (.*) Mumble/} $file;

rdsa()

Requires non-PDL DSA module. Contact Frossie (frossie@jach.hawaii.edu) Usage:

 ([$xaxis],$data) = rdsa($file)

 $a = rdsa 'file.sdf'

isbigendian()

rasc()

  $pdl->rasc("filename" [,$noElements]);
      Where:
        filename is the name of the ASCII file to read
        $noElements is the optional number of elements in the file to read.
            (If not present, all of the file will be read to fill up $pdl).
        $pdl can be of type float or double for more precision.

  #  (test.num is an ascii file with 20 numbers. One number per line.)
  $in = PDL->null;
  $num = 20;
  $in->rasc('test.num',20);
  $imm = zeroes(float,20,2);
  $imm->rasc('test.num');

rcube

 $cube = rcube \&reader_function, @files;

 $cube = rcube \&rfits, glob("*.fits");

The reading function (e.g. rfits, readfraw) (passed as a reference) and files are the arguments.

The cube is created as the same X,Y dims and datatype as the first image specified. The Z dim is simply the number of images.  

bswap2

  Signature: (x(); )

bswap4

  Signature: (x(); )

bswap8

  Signature: (x(); )

AUTHOR

Index

NAME

DESCRIPTION

SYNOPSIS

FUNCTIONS

rfits()

wfits()

rcols()

wcols()

swcols()

rgrep()

rdsa()

isbigendian()

rasc()

rcube

bswap2

bswap4

bswap8

AUTHOR