NAME

PDL::IO::HDF - A PDL interface to the HDF4 library.

SYNOPSIS

  use PDL;
  use PDL::IO::HDF;
  # Open file 'foo.hdf' with all hdf interface:
  my $HDF = PDL::IO::HDF->new("foo.hdf");
  # You can call functions from either the SD or VS interfaces:
  $HDF->{SD}->SDget("Foo_data");
  $HDF->{VS}->VSgetnames();
  # To close the file:
  $HDF->close();

DESCRIPTION

This library provides functions to manipulate HDF files with the SD, VS, and V HDF interfaces.

For more information on HDF, see http://hdf.ncsa.uiuc.edu/

The 'new' function of this package uses the 'new' functions for the individual HDF interfaces. This allows you to use all of the interfaces at one time (if you don't mind the extended syntax).

Actually using the HDF files comes down to using one of the particular interfaces, for that see the docs on those modules.

CONSTANTS

These constants are now implemented using the perl 'use constant' pragma.

Previously, they were just scalars that were changeable (which is a no-no).

See constant(1) for more info on how to use these in your code.

Access Modes

DFACC_READ: Open the file in read-only mode.
DFACC_WRITE: Open the file in write-only mode.
DFACC_CREATE: Clobber the file (create it if it doesn't exist, and then open with RW mode).
DFACC_ALL: Open the file in read-write mode.
DFACC_RDONLY: Same as DFACC_READ
DFACC_RDWR: Open the file in read-write mode.

HDF4 Data Type Codes:

DFNT_UCHAR: HDF's unsigned char ~= PDL's byte
DFNT_CHAR: HDF's char ~= PDL's byte
DFNT_FLOAT32: HDF's 32-bit float ~= PDL's float
DFNT_FLOAT64: HDF's 64-bit float ~= PDL's double
DFNT_INT8: HDF's 8-bit integer ~= PDL's byte
DFNT_UINT8: HDF's 8-bit unsigned integer ~= PDL's byte
DFNT_INT16: HDF's 16-bit integer ~= PDL's short
DFNT_UINT16: HDF's 16-bit unsigned integer ~= PDL's ushort
DFNT_INT32: HDF's 32-bit integer ~= PDL's long
DFNT_INT64: HDF's 32-bit integer ~= PDL's long

Misc. HDF Library Constants:

MAX_NC_NAME: This is the max name length for SDS variables, attribtues, and just about anything else.
MAX_VAR_DIMS: This is the max number of dims a HDF variable can have.
VNAMELENMAX: Max length of V interface names.

CURRENT AUTHOR & MAINTAINER

Judd Taylor, Orbital Systems, Ltd. judd dot t at orbitalsystems dot com

PREVIOUS AUTHORS

Patrick Leilde patrick.leilde@ifremer.fr contribs of Olivier Archer olivier.archer@ifremer.fr