Char(r)        User Contributed Perl Documentation        Char(r)



NAME
       PDL::Char -- PDL subclass which allows reading and writing
       of fixed-length character strings as byte PDLs

SYNOPSIS
        use PDL;
        use PDL::Char;

        my $pchar = PDL::Char->new( [['abc', 'def', 'ghi'],['jkl', 'mno', 'pqr']] );

        $pchar->setstr(1,0,'foo');

        print $pchar; # 'string' bound to "", perl stringify function
        # Prints:
        # [
        #  ['abc' 'foo' 'ghi']
        #  ['jkl' 'mno' 'pqr']
        # ]

        print $pchar->atstr(2,0);
        # Prints:
        # ghi


DESCRIPTION
       This subclass of PDL allows one to manipulate PDLs of
       'byte' type as if they were made of fixed length strings,
       not just numbers.

       This type of behavior is useful when you want to work with
       charactar grids.  The indexing is done on a string level
       and not a character level for the 'setstr' and 'atstr'
       commands.

       This module is in particular useful for writing NetCDF
       files that include character data using the PDL::NetCDF
       module.

FUNCTIONS
       new

       Function to create a byte PDL from a string, list of
       strings, list of list of strings, etc.

        # create a new PDL::Char from a perl array of strings
        $strpdl = PDL::Char->new( ['abc', 'def', 'ghij'] );

        # Convert a PDL of type 'byte' to a PDL::Char
        $strpdl1 = PDL::Char->new (sequence (byte, 4, 5)+99);

        $pdlchar3d = PDL::Char->new([['abc','def','ghi'],['jkl', 'mno', 'pqr']]);


       string

       Function to print a character PDL (created by 'char') in a
       pretty format.





        $char = PDL::Char->new( [['abc', 'def', 'ghi'], ['jkl', 'mno', 'pqr']] );
        print $char; # 'string' bound to "", perl stringify function
        # Prints:
        # [
        #  ['abc' 'def' 'ghi']
        #  ['jkl' 'mno' 'pqr']
        # ]

        # 'string' is overloaded to the "" operator, so:
        # print $char;
        # should have the same effect.


       setstr

       Function to set one string value in a character PDL.  The
       input position is the position of the string, not a char-
       acter in the string.  The first dimension is assumed to be
       the length of the string.

       The input string will be null-padded if the string is
       shorter than the first dimension of the PDL.  It will be
       truncated if it is longer.

        $char = PDL::Char->new( [['abc', 'def', 'ghi'], ['jkl', 'mno', 'pqr']] );
        $char->setstr(0,1, 'foobar');
        print $char; # 'string' bound to "", perl stringify function
        # Prints:
        # [
        #  ['abc' 'def' 'ghi']
        #  ['foo' 'mno' 'pqr']
        # ]
        $char->setstr(2,1, 'f');
        print $char; # 'string' bound to "", perl stringify function
        # Prints:
        # [
        #  ['abc' 'def' 'ghi']
        #  ['foo' 'mno' 'f']      -> note that this 'f' is stored "f\0\0"
        # ]


       atstr

       Function to fetch one string value from a PDL::Char type
       PDL, given a position within the PDL.  The input position
       of the string, not a character in the string.  The length
       of the input string is the implied first dimension.

        $char = PDL::Char->new( [['abc', 'def', 'ghi'], ['jkl', 'mno', 'pqr']] );
        print $char->atstr(0,1);
        # Prints:
        # jkl




perl v5.6.1                 2001-05-27                    Char(r)