.. include:: defs.rst .. _installation: Installation ============ |zfp| consists of four distinct parts: a compression library written in C, a set of C++ header files that implement compressed arrays and corresponding C wrappers, optional Python and Fortran bindings, and a set of C and C++ examples and utilities. The main compression codec is written in C and should conform to both the ISO C89 and C99 standards. The C++ array classes are implemented entirely in header files and can be included as is, but since they call the compression library, applications must link with |libzfp|. |zfp| is preferably built using `CMake `__, although the core library can also be built using GNU make on Linux, macOS, and MinGW. |zfp| conforms to various language standards, including C89, C99, C++98, C++11, and C++14. .. note:: |zfp| requires compiler support for 64-bit integers. .. _cmake_builds: CMake Builds ------------ To build |zfp| using `CMake `__ on Linux or macOS, start a Unix shell and type:: cd zfp-1.0.1 mkdir build cd build cmake .. make To also build the examples, replace the cmake line with:: cmake -DBUILD_EXAMPLES=ON .. By default, CMake builds will attempt to locate and use `OpenMP `__. To disable OpenMP, type:: cmake -DZFP_WITH_OPENMP=OFF .. To build |zfp| using Visual Studio on Windows, start a DOS shell and type:: cd zfp-1.0.1 mkdir build cd build cmake .. cmake --build . --config Release This builds |zfp| in release mode. Replace 'Release' with 'Debug' to build |zfp| in debug mode. See the instructions for Linux on how to change the cmake line to also build the example programs. .. _gnu_builds: GNU Builds ---------- To build |zfp| using `gcc `__ without `OpenMP `__, type:: cd zfp-1.0.1 gmake This builds |libzfp| as a static library as well as the |zfp| command-line utility. To enable OpenMP parallel compression, type:: gmake ZFP_WITH_OPENMP=1 .. note:: GNU builds expose only limited functionality of |zfp|. For instance, CUDA and Python support are not included. For full functionality, build |zfp| using CMake. Testing ------- To test that |zfp| is working properly, type:: ctest or using GNU make:: gmake test If the GNU build or regression tests fail, it is possible that some of the macros in the file :file:`Config` have to be adjusted. Also, the tests may fail due to minute differences in the computed floating-point fields being compressed, which will be indicated by checksum errors. If most tests succeed and the failures result in byte sizes and error values reasonably close to the expected values, then it is likely that the compressor is working correctly. .. index:: single: Build Targets .. _targets: Build Targets ------------- To specify which components to build, set the macros below to :code:`ON` (CMake) or :code:`1` (GNU make), e.g., :: cmake -DBUILD_UTILITIES=OFF -DBUILD_EXAMPLES=ON .. or using GNU make :: gmake BUILD_UTILITIES=0 BUILD_EXAMPLES=1 Regardless of the settings below, |libzfp| will always be built. .. c:macro:: BUILD_ALL Build all subdirectories; enable all options (except :c:macro:`BUILD_SHARED_LIBS`). Default: off. .. c:macro:: BUILD_CFP Build |libcfp| for C bindings to the compressed-array classes. Default: off. .. c:macro:: BUILD_ZFPY Build |zfpy| for Python bindings to the C API. CMake will attempt to automatically detect the Python installation to use. If CMake finds multiple Python installations, it will use the newest one. To specify a specific Python installation to use, set :c:macro:`PYTHON_LIBRARY` and :c:macro:`PYTHON_INCLUDE_DIR` on the cmake line:: cmake -DBUILD_ZFPY=ON -DPYTHON_LIBRARY=/path/to/lib/libpython2.7.so -DPYTHON_INCLUDE_DIR=/path/to/include/python2.7 .. CMake default: off. GNU make default: off and ignored. .. c:macro:: BUILD_ZFORP Build |libzforp| for Fortran bindings to the C API. Requires Fortran standard 2018 or later. GNU make users may specify the Fortran compiler to use via :: gmake BUILD_ZFORP=1 FC=/path/to/fortran-compiler Default: off. .. c:macro:: BUILD_UTILITIES Build |zfpcmd| command-line utility for compressing binary files. Default: on. .. c:macro:: BUILD_EXAMPLES Build code examples. Default: off. .. c:macro:: BUILD_TESTING Build |testzfp| tests. Default: on. .. c:macro:: BUILD_TESTING_FULL Build all unit tests. Default: off. .. c:macro:: BUILD_SHARED_LIBS Build shared objects (:file:`.so`, :file:`.dylib`, or :file:`.dll` files). CMake default: on. GNU make default: off. .. note:: On macOS, add :code:`OS=mac` when building shared libraries with GNU make. .. index:: single: Configuration .. _config: Configuration ------------- The behavior of |zfp| can be configured at compile time via a set of macros in the same manner that :ref:`build targets ` are specified, e.g., :: cmake -DZFP_WITH_OPENMP=OFF .. .. c:macro:: ZFP_INT64 .. c:macro:: ZFP_INT64_SUFFIX .. c:macro:: ZFP_UINT64 .. c:macro:: ZFP_UINT64_SUFFIX 64-bit signed and unsigned integer types and their literal suffixes. Platforms on which :code:`long int` is 32 bits wide may require :code:`long long int` as type and :code:`ll` as suffix. These macros are relevant **only** when compiling in C89 mode. When compiling in C99 mode, integer types are taken from :file:`stdint.h`. Defaults: :code:`long int`, :code:`l`, :code:`unsigned long int`, and :code:`ul`, respectively. .. c:macro:: ZFP_WITH_OPENMP CMake and GNU make macro for enabling or disabling OpenMP support. CMake builds will by default enable OpenMP when available. Set this macro to 0 or OFF to disable OpenMP support. For GNU builds, OpenMP is disabled by default. Set this macro to 1 or ON to enable OpenMP support. See also OMPFLAGS in :file:`Config` in case the compiler does not recognize ``-fopenmp``. For example, Apple clang requires ``OMPFLAGS=-Xclang -fopenmp``, ``LDFLAGS=-lomp``, and an installation of ``libomp``. CMake default: on. GNU make default: off. .. c:macro:: ZFP_WITH_CUDA CMake macro for enabling or disabling CUDA support for GPU compression and decompression. When enabled, CUDA and a compatible host compiler must be installed. For a full list of compatible compilers, please consult the `NVIDIA documentation `__. If a CUDA installation is in the user's path, it will be automatically found by CMake. Alternatively, the CUDA binary directory can be specified using the :envvar:`CUDA_BIN_DIR` environment variable. CMake default: off. GNU make default: off and ignored. .. _rounding: .. c:macro:: ZFP_ROUNDING_MODE **Experimental feature**. By default, |zfp| coefficients are truncated, not rounded, which can result in biased errors (see FAQ :ref:`#30 `). To counter this, two rounding modes are available: :code:`ZFP_ROUND_FIRST` (round during compression; analogous to mid-tread quantization) and :code:`ZFP_ROUND_LAST` (round during decompression; analogous to mid-riser quantization). With :code:`ZFP_ROUND_LAST`, the values returned on decompression are slightly modified (and usually closer to the original values) without impacting the compressed data itself. This rounding mode works with all :ref:`compression modes `. With :code:`ZFP_ROUND_FIRST`, the values are modified before compression, thus impacting the compressed stream. This rounding mode tends to be more effective at reducing bias, but is invoked only with :ref:`fixed-precision ` and :ref:`fixed-accuracy ` compression modes. Both of these rounding modes break the regression tests since they alter the compressed or decompressed representation, but they may be used with libraries built with the default rounding mode, :code:`ZFP_ROUND_NEVER`, and versions of |zfp| that do not support a rounding mode with no adverse effects. Note: :c:macro:`ZFP_ROUNDING_MODE` is currently supported only by the :code:`serial` and :code:`omp` :ref:`execution policies `. Default: :code:`ZFP_ROUND_NEVER`. .. c:macro:: ZFP_WITH_TIGHT_ERROR **Experimental feature**. When enabled, this feature takes advantage of the error reduction associated with proper rounding; see :c:macro:`ZFP_ROUNDING_MODE`. The reduced error due to rounding allows the tolerance in :ref:`fixed-accuracy mode ` to be satisfied using fewer bits of compressed data. As a result, when enabled, the observed maximum absolute error is closer to the tolerance and the compression ratio is increased. This feature requires the rounding mode to be :code:`ZFP_ROUND_FIRST` or :code:`ZFP_ROUND_LAST` and is supported only by the :code:`serial` and :code:`omp` :ref:`execution policies `. Default: undefined/off. .. c:macro:: ZFP_WITH_DAZ When enabled, blocks consisting solely of subnormal floating-point numbers (tiny numbers close to zero) are treated as blocks of all zeros (DAZ = denormals-are-zero). The main purpose of this option is to avoid the potential for floating-point overflow in the |zfp| implementation that may occur in step 2 of the :ref:`lossy compression algorithm ` when converting to |zfp|'s block-floating-point representation (see `Issue #119 `__). Such overflow tends to be benign but loses all precision and usually results in "random" subnormals upon decompression. When enabled, compressed streams may differ slightly but are decompressed correctly by libraries built without this option. This option may break some regression tests. Note: :c:macro:`ZFP_WITH_DAZ` is currently ignored by all :ref:`execution policies ` other than :code:`serial` and :code:`omp`. Default: undefined/off. .. c:macro:: ZFP_WITH_ALIGNED_ALLOC Use aligned memory allocation in an attempt to align compressed blocks on hardware cache lines. Default: undefined/off. .. c:macro:: ZFP_WITH_CACHE_TWOWAY Use a two-way skew-associative rather than direct-mapped cache. This incurs some overhead that may be offset by better cache utilization. Default: undefined/off. .. c:macro:: ZFP_WITH_CACHE_FAST_HASH Use a simpler hash function for cache line lookup. This is faster but may lead to more collisions. Default: undefined/off. .. c:macro:: ZFP_WITH_CACHE_PROFILE Enable cache profiling to gather and print statistics on cache hit and miss rates. Default: undefined/off. .. c:macro:: BIT_STREAM_WORD_TYPE Unsigned integer type used for buffering bits. Wider types tend to give higher performance at the expense of lower :ref:`bit rate granularity `. For portability of compressed files between little and big endian platforms, :c:macro:`BIT_STREAM_WORD_TYPE` should be set to :c:type:`uint8`. Default: :c:type:`uint64`. .. c:macro:: ZFP_BIT_STREAM_WORD_SIZE CMake macro for indirectly setting :c:macro:`BIT_STREAM_WORD_TYPE`. Valid values are 8, 16, 32, 64. Default: 64. .. c:macro:: BIT_STREAM_STRIDED Enable support for strided bit streams that allow for non-contiguous memory layouts, e.g., to enable progressive access. Default: undefined/off. .. c:macro:: CFP_NAMESPACE Macro for renaming the outermost |cfp| namespace, e.g., to avoid name clashes. Default: :code:`cfp`. .. c:macro:: PYTHON_LIBRARY Path to the Python library, e.g., :file:`/usr/lib/libpython2.7.so`. CMake default: undefined/off. GNU make default: off and ignored. .. c:macro:: PYTHON_INCLUDE_DIR Path to the Python include directory, e.g., :file:`/usr/include/python2.7`. CMake default: undefined/off. GNU make default: off and ignored. Dependencies ------------ The core |zfp| library and compressed arrays require only a C89 and C++98 compiler. The optional components have additional dependencies, as outlined in the sections below. CMake ^^^^^ CMake builds require version 3.9 or later. CMake is available `here `__. OpenMP ^^^^^^ OpenMP support requires OpenMP 2.0 or later. CUDA ^^^^ CUDA support requires CUDA 7.0 or later, CMake, and a compatible host compiler (see :c:macro:`ZFP_WITH_CUDA`). C/C++ ^^^^^ The |zfp| C library and |cfp| C wrappers around the compressed-array classes conform to the C90 standard (`ISO/IEC 9899:1990 `__). The C++ classes conform to the C++98 standard (`ISO/IEC 14882:1998 `__). Python ^^^^^^ The optional Python bindings require CMake and the following minimum versions: * Python: Python 2.7 & Python 3.5 * Cython: 0.22 * NumPy: 1.8.0 The necessary dependencies can be installed using ``pip`` and the |zfp| :file:`requirements.txt`:: pip install -r $ZFP_ROOT/python/requirements.txt Fortran ^^^^^^^ The optional Fortran bindings require a Fortran 2018 compiler.