Installation instructions
*************************

Since Blaze is a header-only library, setting up the Blaze library on a particular system is
a fairly easy two step process. In the following, this two step process is explained in detail,
preceded only by a short summary of the requirements.


Requirements
************

For maximum performance the Blaze library expects you to have a BLAS library installed (Intel
MKL, ACML, Atlas, Goto, ...). If you don't have a BLAS library installed on your system, Blaze
will still work and will not be reduced in functionality, but performance may be limited. Thus
it is strongly recommended to install a BLAS library.

Additionally, for computing the determinant of a dense matrix, for the decomposition of dense
matrices, for the dense matrix inversion, and for the computation of eigenvalues and singular
values Blaze requires LAPACK. When either of these features is used it is necessary to link
the LAPACK library to the final executable. If no LAPACK library is available the use of these
features will result in a linker error.

Furthermore, it is possible to use Boost threads to run numeric operations in parallel. In this
case the Boost library is required to be installed on your system. It is recommended to use the
newest Boost library available, but Blaze requires at minimum the Boost version 1.54.0. If you
don't have Boost installed on your system, you can download it for free from 'www.boost.org'.


Step 1: Installation
********************

Installation via CMake
----------------------

The first step is the installation of the Blaze header files. The most convenient way to do this
is via CMake (https://cmake.org). Linux and macOS users can use the following two lines to copy
the Blaze headers in the './blaze' subdirectory to the directory '${CMAKE_INSTALL_PREFIX}/include'
and the package configuration files to '${CMAKE_INSTALL_PREFIX}/share/blaze/cmake'.

cmake -DCMAKE_INSTALL_PREFIX=/usr/local/
sudo make install

Windows users can do the same via the cmake-gui. Alternatively, it is possible to include Blaze
by adding the following lines in any 'CMakeLists.txt' file:

find_package( blaze )
if( blaze_FOUND )
   add_library( blaze_target INTERFACE )
   target_link_libraries( blaze_target INTERFACE blaze::blaze )
endif()


Installation via the VC++ Packaging Tool
----------------------------------------

An alternate way to install Blaze for Windows users is Microsoft's VC++ Packaging Tool (vcpkg;
https://github.com/Microsoft/vcpkg). Blaze can be installed via the command line:

C:\src\vcpkg> .\vcpkg install blaze

The tool automatically downloads the latest Blaze release and copies the header files to the
common include directory.


Manual Installation on Linux/macOS
----------------------------------

Since Blaze only consists of header files, the './blaze' subdirectory can be simply copied to a
standard include directory (note that this requires root privileges):

cp -r ./blaze /usr/local/include

Alternatively, on Unix-based machines (which includes Linux and Mac OS X) the 'CPLUS_INCLUDE_PATH'
environment variable can be set. The specified directory will be searched after any directories
specified on the command line with the option \c -I and before the standard default directories
(such as '/usr/local/include' and ‘/usr/include'). Assuming a user named 'Jon', the environment
variable can be set as follows:

CPLUS_INCLUDE_PATH=/usr/home/jon/blaze
export CPLUS_INCLUDE_PATH

Last but not least, the './blaze' subdirectory can be explicitly specified on the command line.
The following example demonstrates this by means of the GNU C++ compiler:

g++ -I/usr/home/jon/blaze -o BlazeTest BlazeTest.cpp


Manual Installation on Windows
------------------------------

Windows doesn't have a standard include directory. Therefore the Blaze header files can be copied
to any other directory or simply left in the default Blaze directory. However, the chosen include
directory has to be explicitly specified as include path. In Visual Studio, this is done via the
project property pages, configuration properties, C/C++, General settings. Here the additional
include directories can be specified.


Step 2: Configuration
*********************

The second step is the configuration and customization of the Blaze library. Many aspects of Blaze
can be adapted to specific requirements, environments and architectures. The most convenient way
to configure Blaze is to modify the headers in the './blaze/config/' subdirectory by means of
CMake (https://cmake.org). Alternatively these header files can be customized manually. In both
cases, however, the files are modified. If this is not an option it is possible to configure Blaze
via the command line (see https://bitbucket.org/blaze-lib/blaze/wiki/Configuration%20Files or
or the documentation in the configuration files).

Since the default settings are reasonable for most systems this step can also be skipped. However,
in order to achieve maximum performance a customization of at least the following configuration
files is required:

 - <blaze/config/BLAS.h>: Via this configuration file Blaze can be enabled to use a third-party
   BLAS library for several basic linear algebra functions (such as for instance dense matrix
   multiplications). In case no BLAS library is used, all linear algebra functions use the default
   implementations of the Blaze library and therefore BLAS is not a requirement for the compilation
   process. However, please note that performance may be limited.
 - <blaze/config/CacheSize.h>: This file contains the hardware specific cache settings. Blaze
   uses this information to optimize its cache usage. For maximum performance it is recommended to
   adapt these setting to a specific target architecture.
 - <blaze/config/Thresholds.h>: This file contains all thresholds for the customization of the
   Blaze compute kernels. In order to tune the kernels for a specific architecture and to maximize
   performance it can be necessary to adjust the thresholds, especially for a parallel execution.

For an overview of other customization options and more details, please see the Blaze wiki at
https://bitbucket.org/blaze-lib/blaze/wiki/Home.


Blaze Version
*************

The current major and minor version number of the Blaze library can be found in the
<blaze/system/Version.h> header file. It is automatically included via the <blaze/Blaze.h> header
file. The file contains the two following macros, which can for instance be used for conditional
compilation:

#define BLAZE_MAJOR_VERSION 3
#define BLAZE_MINOR_VERSION 5
#define BLAZE_PATCH_VERSION 0
