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Overview

These wrappers provide a high and low-level Lua interface to the HDF5 library. The code provided here should be embedded in your application to give it flexible interaction with HDF5.

Example usage

High-level interface

This demonstrates the simplest usage of the high-level HDF5 interface. It creates a file with a (numeric array-valued) data set named 'the_dataset' and group named 'the_group' containing a (string-valued) data set called 'the_message'.

local hdf5 = require 'LuaHDF5'
local array = require 'array'

local the_array = array.array({16,32,64}, 'double')
local the_h5file = hdf5.File("outfile.h5", "w")
local the_group = the_h5file:require_group("the_group")
the_group["the_message"] = "here is the message"
the_h5file["the_dataset"] = the_array
the_h5file:close()

Low-level bindings

Access to the low-level HDF5 library follows exactly the HDF5 API specification, in other words there is one-to-one mapping between (most) HDF5 functions and their low-level Lua wrappers. Some HDF5 functions are not wrapped, although they can be recognized by the wrapper generator parse.py with easy modifications.

local H5 = require 'HDF5'
local buffer = require 'buffer'

local def = H5.H5P_DEFAULT
local trunc = H5.H5F_ACC_TRUNC
local double = H5.H5T_NATIVE_DOUBLE

local current_size = H5.new_hsize_t_arr{10,10,10}
local maximum_size = H5.new_hsize_t_arr{10,10,10}

local fid = H5.H5Fcreate("outfile.h5", trunc, def, def)
local sid = H5.H5Screate(H5.H5S_SIMPLE)
H5.H5Sset_extent_simple(sid, 3, current_size, maximum_size)

local did = H5.H5Dcreate2(fid, "dataset", double, sid, def, def, def)
...

Build instructions

Make sure you have the HDF5 sources installed.

Create a file called Makefile.in which contains macros like these:

LUA_HOME = /path/to/lua-5.2.1
HDF_HOME = /path/to/hdf5-1.8.10

Additional compile flags are optional:

CC = gcc
CFLAGS = -Wall -O2
LVER = lua-5.2.1 # can be lua-5.1 or other
USE_MPIO = 1 # wrap HDF5 collectve IO routines

Optionally, you may install local Lua sources by typing make lua.

Run make.

Running tests

Type ./main alltests.lua.

Compatibility and conventions

Lua HDF5 contains a Python script to generate low-level wrapper code which has been tested for HDF5 library versions between 1.8.3 and 1.8.10. The generated Lua code is tested for Lua 5.2.1, although small adjustments may be made to support Lua 5.0 and 5.1.

An example program is provided which embeds the Lua HDF5 interface. It loads the HDF5 module into the package.loaded.HDF5 table, which can then be accessed within Lua by typing local H5 = require 'HDF5'. The module can be given global visibility to Lua scripts by passing calling luaL_requiref(L, "HDF5", luaopen_hdf5, 1); with 1 instead of 0 as the last argument.

License

This code is made freely available for anybody's use. I only ask that if you find it useful, please send me an email about how it works, and in what project you are using it.

The Lua HDF5 wrappers are licensed under the same terms as Lua itself.

Copyright (c) 2012, Jonathan Zrake jonathan.zrake@gmail.com

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.