.. _chapter-installation:
============
Installation
============
Getting the source code
=======================
.. _section-source:
You can start with the `latest stable release
<http://ceres-solver.org/ceres-solver-1.13.0.tar.gz>`_ . Or if you want
the latest version, you can clone the git repository
.. code-block:: bash
git clone https://ceres-solver.googlesource.com/ceres-solver
.. _section-dependencies:
Dependencies
============
Ceres relies on a number of open source libraries, some of which are
optional. For details on customizing the build process, see
:ref:`section-customizing` .
- `Eigen <http://eigen.tuxfamily.org/index.php?title=Main_Page>`_
3.2.2 or later **strongly** recommended, 3.1.0 or later **required**.
.. NOTE ::
Ceres can also use Eigen as a sparse linear algebra
library. Please see the documentation for ``EIGENSPARSE`` for
more details.
- `CMake <http://www.cmake.org>`_ 2.8.0 or later.
**Required on all platforms except for Android.**
- `glog <https://github.com/google/glog>`_ 0.3.1 or
later. **Recommended**
``glog`` is used extensively throughout Ceres for logging detailed
information about memory allocations and time consumed in various
parts of the solve, internal error conditions etc. The Ceres
developers use it extensively to observe and analyze Ceres's
performance. `glog <https://github.com/google/glog>`_ allows you to
control its behaviour from the command line. Starting with
``-logtostderr`` you can add ``-v=N`` for increasing values of ``N``
to get more and more verbose and detailed information about Ceres
internals.
Unfortunately, the current version of `google-glog
<https://github.com/google/glog>`_ does not build using the Android
NDK. So, Ceres also ships with a minimal replacement of ``glog``
called ``miniglog`` that can be enabled with the ``MINIGLOG`` build
option.
So, in an attempt to reduce dependencies, it is tempting to use
`miniglog` on platforms other than Android. While there is nothing
preventing the user from doing so, we strongly recommend against
it. ``miniglog`` has worse performance than ``glog`` and is much
harder to control and use.
.. NOTE ::
If you are compiling ``glog`` from source, please note that
currently, the unit tests for ``glog`` (which are enabled by
default) do not compile against a default build of ``gflags`` 2.1
as the gflags namespace changed from ``google::`` to
``gflags::``. A patch to fix this is available from `here
<https://code.google.com/p/google-glog/issues/detail?id=194>`_.
- `gflags <https://github.com/gflags/gflags>`_. Needed to build
examples and tests.
- `SuiteSparse
<http://faculty.cse.tamu.edu/davis/suitesparse.html>`_. Needed for
solving large sparse linear systems. **Optional; strongly recomended
for large scale bundle adjustment**
- `CXSparse <http://faculty.cse.tamu.edu/davis/suitesparse.html>`_.
Similar to ``SuiteSparse`` but simpler and slower. CXSparse has
no dependencies on ``LAPACK`` and ``BLAS``. This makes for a simpler
build process and a smaller binary. **Optional**
- `BLAS <http://www.netlib.org/blas/>`_ and `LAPACK
<http://www.netlib.org/lapack/>`_ routines are needed by
``SuiteSparse``, and optionally used by Ceres directly for some
operations.
On ``UNIX`` OSes other than Mac OS X we recommend `ATLAS
<http://math-atlas.sourceforge.net/>`_, which includes ``BLAS`` and
``LAPACK`` routines. It is also possible to use `OpenBLAS
<https://github.com/xianyi/OpenBLAS>`_ . However, one needs to be
careful to `turn off the threading
<https://github.com/xianyi/OpenBLAS/wiki/faq#wiki-multi-threaded>`_
inside ``OpenBLAS`` as it conflicts with use of threads in Ceres.
Mac OS X ships with an optimized ``LAPACK`` and ``BLAS``
implementation as part of the ``Accelerate`` framework. The Ceres
build system will automatically detect and use it.
For Windows things are much more complicated. `LAPACK For
Windows <http://icl.cs.utk.edu/lapack-for-windows/lapack/>`_
has detailed instructions..
**Optional but required for** ``SuiteSparse``.
.. _section-linux:
Linux
=====
We will use `Ubuntu <http://www.ubuntu.com>`_ as our example linux
distribution.
.. NOTE::
Up to at least Ubuntu 14.04, the SuiteSparse package in the official
package repository (built from SuiteSparse v3.4.0) **cannot** be used
to build Ceres as a *shared* library. Thus if you want to build
Ceres as a shared library using SuiteSparse, you must perform a
source install of SuiteSparse or use an external PPA (see `bug report
here
<https://bugs.launchpad.net/ubuntu/+source/suitesparse/+bug/1333214>`_).
It is recommended that you use the current version of SuiteSparse
(4.2.1 at the time of writing).
Start by installing all the dependencies.
.. code-block:: bash
# CMake
sudo apt-get install cmake
# google-glog + gflags
sudo apt-get install libgoogle-glog-dev
# BLAS & LAPACK
sudo apt-get install libatlas-base-dev
# Eigen3
sudo apt-get install libeigen3-dev
# SuiteSparse and CXSparse (optional)
# - If you want to build Ceres as a *static* library (the default)
# you can use the SuiteSparse package in the main Ubuntu package
# repository:
sudo apt-get install libsuitesparse-dev
# - However, if you want to build Ceres as a *shared* library, you must
# add the following PPA:
sudo add-apt-repository ppa:bzindovic/suitesparse-bugfix-1319687
sudo apt-get update
sudo apt-get install libsuitesparse-dev
We are now ready to build, test, and install Ceres.
.. code-block:: bash
tar zxf ceres-solver-1.13.0.tar.gz
mkdir ceres-bin
cd ceres-bin
cmake ../ceres-solver-1.13.0
make -j3
make test
# Optionally install Ceres, it can also be exported using CMake which
# allows Ceres to be used without requiring installation, see the documentation
# for the EXPORT_BUILD_DIR option for more information.
make install
You can also try running the command line bundling application with one of the
included problems, which comes from the University of Washington's BAL
dataset [Agarwal]_.
.. code-block:: bash
bin/simple_bundle_adjuster ../ceres-solver-1.13.0/data/problem-16-22106-pre.txt
This runs Ceres for a maximum of 10 iterations using the
``DENSE_SCHUR`` linear solver. The output should look something like
this.
.. code-block:: bash
iter cost cost_change |gradient| |step| tr_ratio tr_radius ls_iter iter_time total_time
0 4.185660e+06 0.00e+00 1.09e+08 0.00e+00 0.00e+00 1.00e+04 0 7.59e-02 3.37e-01
1 1.062590e+05 4.08e+06 8.99e+06 5.36e+02 9.82e-01 3.00e+04 1 1.65e-01 5.03e-01
2 4.992817e+04 5.63e+04 8.32e+06 3.19e+02 6.52e-01 3.09e+04 1 1.45e-01 6.48e-01
3 1.899774e+04 3.09e+04 1.60e+06 1.24e+02 9.77e-01 9.26e+04 1 1.43e-01 7.92e-01
4 1.808729e+04 9.10e+02 3.97e+05 6.39e+01 9.51e-01 2.78e+05 1 1.45e-01 9.36e-01
5 1.803399e+04 5.33e+01 1.48e+04 1.23e+01 9.99e-01 8.33e+05 1 1.45e-01 1.08e+00
6 1.803390e+04 9.02e-02 6.35e+01 8.00e-01 1.00e+00 2.50e+06 1 1.50e-01 1.23e+00
Ceres Solver v1.13.0 Solve Report
----------------------------------
Original Reduced
Parameter blocks 22122 22122
Parameters 66462 66462
Residual blocks 83718 83718
Residual 167436 167436
Minimizer TRUST_REGION
Dense linear algebra library EIGEN
Trust region strategy LEVENBERG_MARQUARDT
Given Used
Linear solver DENSE_SCHUR DENSE_SCHUR
Threads 1 1
Linear solver threads 1 1
Linear solver ordering AUTOMATIC 22106, 16
Cost:
Initial 4.185660e+06
Final 1.803390e+04
Change 4.167626e+06
Minimizer iterations 6
Successful steps 6
Unsuccessful steps 0
Time (in seconds):
Preprocessor 0.261
Residual evaluation 0.082
Jacobian evaluation 0.412
Linear solver 0.442
Minimizer 1.051
Postprocessor 0.002
Total 1.357
Termination: CONVERGENCE (Function tolerance reached. |cost_change|/cost: 1.769766e-09 <= 1.000000e-06)
.. section-osx:
Mac OS X
========
.. NOTE::
Ceres will not compile using Xcode 4.5.x (Clang version 4.1) due to a
bug in that version of Clang. If you are running Xcode 4.5.x, please
update to Xcode >= 4.6.x before attempting to build Ceres.
On OS X, you can either use `MacPorts <https://www.macports.org/>`_ or
`Homebrew <http://mxcl.github.com/homebrew/>`_ to install Ceres Solver.
If using `MacPorts <https://www.macports.org/>`_, then
.. code-block:: bash
sudo port install ceres-solver
will install the latest version.
If using `Homebrew <http://mxcl.github.com/homebrew/>`_ and assuming
that you have the ``homebrew/science`` [#f1]_ tap enabled, then
.. code-block:: bash
brew install ceres-solver
will install the latest stable version along with all the required
dependencies and
.. code-block:: bash
brew install ceres-solver --HEAD
will install the latest version in the git repo.
You can also install each of the dependencies by hand using `Homebrew
<http://mxcl.github.com/homebrew/>`_. There is no need to install
``BLAS`` or ``LAPACK`` separately as OS X ships with optimized
``BLAS`` and ``LAPACK`` routines as part of the `vecLib
<https://developer.apple.com/library/mac/#documentation/Performance/Conceptual/vecLib/Reference/reference.html>`_
framework.
.. code-block:: bash
# CMake
brew install cmake
# google-glog and gflags
brew install glog
# Eigen3
brew install eigen
# SuiteSparse and CXSparse
brew install suite-sparse
We are now ready to build, test, and install Ceres.
.. code-block:: bash
tar zxf ceres-solver-1.13.0.tar.gz
mkdir ceres-bin
cd ceres-bin
cmake ../ceres-solver-1.13.0
make -j3
make test
# Optionally install Ceres, it can also be exported using CMake which
# allows Ceres to be used without requiring installation, see the
# documentation for the EXPORT_BUILD_DIR option for more information.
make install
Like the Linux build, you should now be able to run
``bin/simple_bundle_adjuster``.
.. rubric:: Footnotes
.. [#f1] Ceres and many of its dependencies are in `homebrew/science
<https://github.com/Homebrew/homebrew-science>`_ tap. So, if you
don't have this tap enabled, then you will need to enable it as
follows before executing any of the commands in this section.
.. code-block:: bash
brew tap homebrew/science
.. _section-windows:
Windows
=======
.. NOTE::
If you find the following CMake difficult to set up, then you may
be interested in a `Microsoft Visual Studio wrapper
<https://github.com/tbennun/ceres-windows>`_ for Ceres Solver by Tal
Ben-Nun.
On Windows, we support building with Visual Studio 2010 or newer. Note
that the Windows port is less featureful and less tested than the
Linux or Mac OS X versions due to the lack of an officially supported
way of building SuiteSparse and CXSparse. There are however a number
of unofficial ways of building these libraries. Building on Windows
also a bit more involved since there is no automated way to install
dependencies.
.. NOTE:: Using ``google-glog`` & ``miniglog`` with windows.h.
The windows.h header if used with GDI (Graphics Device Interface)
defines ``ERROR``, which conflicts with the definition of ``ERROR``
as a LogSeverity level in ``google-glog`` and ``miniglog``. There
are at least two possible fixes to this problem:
#. Use ``google-glog`` and define ``GLOG_NO_ABBREVIATED_SEVERITIES``
when building Ceres and your own project, as documented `here
<http://google-glog.googlecode.com/svn/trunk/doc/glog.html>`__.
Note that this fix will not work for ``miniglog``, but use of
``miniglog`` is strongly discouraged on any platform for which
``google-glog`` is available (which includes Windows).
#. If you do not require GDI, then define ``NOGDI`` **before**
including windows.h. This solution should work for both
``google-glog`` and ``miniglog`` and is documented for
``google-glog`` `here
<https://code.google.com/p/google-glog/issues/detail?id=33>`__.
#. Make a toplevel directory for deps & build & src somewhere: ``ceres/``
#. Get dependencies; unpack them as subdirectories in ``ceres/``
(``ceres/eigen``, ``ceres/glog``, etc)
#. ``Eigen`` 3.1 (needed on Windows; 3.0.x will not work). There is
no need to build anything; just unpack the source tarball.
#. ``google-glog`` Open up the Visual Studio solution and build it.
#. ``gflags`` Open up the Visual Studio solution and build it.
#. (Experimental) ``SuiteSparse`` Previously SuiteSparse was not
available on Windows, recently it has become possible to build
it on Windows using the `suitesparse-metis-for-windows
<https://github.com/jlblancoc/suitesparse-metis-for-windows>`_
project. If you wish to use ``SuiteSparse``, follow their
instructions for obtaining and building it.
#. (Experimental) ``CXSparse`` Previously CXSparse was not
available on Windows, there are now several ports that enable it
to be, including: `[1] <https://github.com/PetterS/CXSparse>`_
and `[2] <https://github.com/TheFrenchLeaf/CXSparse>`_. If you
wish to use ``CXSparse``, follow their instructions for
obtaining and building it.
#. Unpack the Ceres tarball into ``ceres``. For the tarball, you
should get a directory inside ``ceres`` similar to
``ceres-solver-1.3.0``. Alternately, checkout Ceres via ``git`` to
get ``ceres-solver.git`` inside ``ceres``.
#. Install ``CMake``,
#. Make a dir ``ceres/ceres-bin`` (for an out-of-tree build)
#. Run ``CMake``; select the ``ceres-solver-X.Y.Z`` or
``ceres-solver.git`` directory for the CMake file. Then select the
``ceres-bin`` for the build dir.
#. Try running ``Configure``. It won't work. It'll show a bunch of options.
You'll need to set:
#. ``EIGEN_INCLUDE_DIR_HINTS``
#. ``GLOG_INCLUDE_DIR_HINTS``
#. ``GLOG_LIBRARY_DIR_HINTS``
#. ``GFLAGS_INCLUDE_DIR_HINTS``
#. ``GFLAGS_LIBRARY_DIR_HINTS``
#. (Optional) ``SUITESPARSE_INCLUDE_DIR_HINTS``
#. (Optional) ``SUITESPARSE_LIBRARY_DIR_HINTS``
#. (Optional) ``CXSPARSE_INCLUDE_DIR_HINTS``
#. (Optional) ``CXSPARSE_LIBRARY_DIR_HINTS``
to the appropriate directories where you unpacked/built them. If
any of the variables are not visible in the ``CMake`` GUI, create a
new entry for them. We recommend using the
``<NAME>_(INCLUDE/LIBRARY)_DIR_HINTS`` variables rather than
setting the ``<NAME>_INCLUDE_DIR`` & ``<NAME>_LIBRARY`` variables
directly to keep all of the validity checking, and to avoid having
to specify the library files manually.
#. You may have to tweak some more settings to generate a MSVC
project. After each adjustment, try pressing Configure & Generate
until it generates successfully.
#. Open the solution and build it in MSVC
To run the tests, select the ``RUN_TESTS`` target and hit **Build
RUN_TESTS** from the build menu.
Like the Linux build, you should now be able to run
``bin/simple_bundle_adjuster``.
Notes:
#. The default build is Debug; consider switching it to release mode.
#. Currently ``system_test`` is not working properly.
#. CMake puts the resulting test binaries in ``ceres-bin/examples/Debug``
by default.
#. The solvers supported on Windows are ``DENSE_QR``, ``DENSE_SCHUR``,
``CGNR``, and ``ITERATIVE_SCHUR``.
#. We're looking for someone to work with upstream ``SuiteSparse`` to
port their build system to something sane like ``CMake``, and get a
fully supported Windows port.
.. _section-android:
Android
=======
Download the ``Android NDK`` version ``r9d`` or later. Run
``ndk-build`` from inside the ``jni`` directory. Use the
``libceres.a`` that gets created.
.. _section-ios:
iOS
===
.. NOTE::
You need iOS version 7.0 or higher to build Ceres Solver.
To build Ceres for iOS, we need to force ``CMake`` to find the
toolchains from the iOS SDK instead of using the standard ones. For
example:
.. code-block:: bash
cmake \
-DCMAKE_TOOLCHAIN_FILE=../ceres-solver/cmake/iOS.cmake \
-DEIGEN_INCLUDE_DIR=/path/to/eigen/header \
-DIOS_PLATFORM=<PLATFORM> \
<PATH_TO_CERES_SOURCE>
``PLATFORM`` can be: ``OS``, ``SIMULATOR`` or ``SIMULATOR64``. You can
build for ``OS`` (``armv7``, ``armv7s``, ``arm64``), ``SIMULATOR``
(``i386``) or ``SIMULATOR64`` (``x86_64``) separately and use ``lipo``
to merge them into one static library. See ``cmake/iOS.cmake`` for
more options.
After building, you will get a ``libceres.a`` library, which you will
need to add to your Xcode project.
The default CMake configuration builds a bare bones version of Ceres
Solver that only depends on Eigen (``MINIGLOG`` is compiled into Ceres
if it is used), this should be sufficient for solving small to
moderate sized problems (No ``SPARSE_SCHUR``,
``SPARSE_NORMAL_CHOLESKY`` linear solvers and no ``CLUSTER_JACOBI``
and ``CLUSTER_TRIDIAGONAL`` preconditioners).
If you decide to use ``LAPACK`` and ``BLAS``, then you also need to
add ``Accelerate.framework`` to your Xcode project's linking
dependency.
.. _section-customizing:
Customizing the build
=====================
It is possible to reduce the libraries needed to build Ceres and
customize the build process by setting the appropriate options in
``CMake``. These options can either be set in the ``CMake`` GUI, or
via ``-D<OPTION>=<ON/OFF>`` when running ``CMake`` from the command
line. In general, you should only modify these options from their
defaults if you know what you are doing.
.. NOTE::
If you are setting variables via ``-D<VARIABLE>=<VALUE>`` when
calling ``CMake``, it is important to understand that this forcibly
**overwrites** the variable ``<VARIABLE>`` in the ``CMake`` cache at
the start of *every configure*.
This can lead to confusion if you are invoking the ``CMake`` `curses
<http://www.gnu.org/software/ncurses/ncurses.html>`_ terminal GUI
(via ``ccmake``, e.g. ```ccmake -D<VARIABLE>=<VALUE>
<PATH_TO_SRC>``). In this case, even if you change the value of
``<VARIABLE>`` in the ``CMake`` GUI, your changes will be
**overwritten** with the value passed via ``-D<VARIABLE>=<VALUE>``
(if one exists) at the start of each configure.
As such, it is generally easier not to pass values to ``CMake`` via
``-D`` and instead interactively experiment with their values in the
``CMake`` GUI. If they are not present in the *Standard View*,
toggle to the *Advanced View* with ``<t>``.
Options controlling Ceres configuration
---------------------------------------
#. ``LAPACK [Default: ON]``: By default Ceres will use ``LAPACK`` (&
``BLAS``) if they are found. Turn this ``OFF`` to build Ceres
without ``LAPACK``. Turning this ``OFF`` also disables
``SUITESPARSE`` as it depends on ``LAPACK``.
#. ``SUITESPARSE [Default: ON]``: By default, Ceres will link to
``SuiteSparse`` if it and all of its dependencies are present. Turn
this ``OFF`` to build Ceres without ``SuiteSparse``. Note that
``LAPACK`` must be ``ON`` in order to build with ``SuiteSparse``.
#. ``CXSPARSE [Default: ON]``: By default, Ceres will link to
``CXSparse`` if all its dependencies are present. Turn this ``OFF``
to build Ceres without ``CXSparse``.
#. ``EIGENSPARSE [Default: OFF]``: By default, Ceres will not use
Eigen's sparse Cholesky factorization. The is because this part of
the code is licensed under the ``LGPL`` and since ``Eigen`` is a
header only library, including this code will result in an ``LGPL``
licensed version of Ceres.
.. NOTE::
For good performance, use Eigen version 3.2.2 or later.
#. ``GFLAGS [Default: ON]``: Turn this ``OFF`` to build Ceres without
``gflags``. This will also prevent some of the example code from
building.
#. ``MINIGLOG [Default: OFF]``: Ceres includes a stripped-down,
minimal implementation of ``glog`` which can optionally be used as
a substitute for ``glog``, thus removing ``glog`` as a required
dependency. Turn this ``ON`` to use this minimal ``glog``
implementation.
#. ``SCHUR_SPECIALIZATIONS [Default: ON]``: If you are concerned about
binary size/compilation time over some small (10-20%) performance
gains in the ``SPARSE_SCHUR`` solver, you can disable some of the
template specializations by turning this ``OFF``.
#. ``OPENMP [Default: ON]``: On certain platforms like Android,
multi-threading with ``OpenMP`` is not supported. Turn this ``OFF``
to disable multi-threading.
#. ``CXX11 [Default: OFF]`` *Non-MSVC compilers only*.
Although Ceres does not currently use C++11, it does use
``shared_ptr`` (required) and ``unordered_map`` (if available);
both of which existed in the previous iterations of what became the
C++11 standard: TR1 & C++0x. As such, Ceres can compile on
pre-C++11 compilers, using the TR1/C++0x versions of ``shared_ptr``
& ``unordered_map``.
Note that when using GCC & Clang, compiling against the TR1/C++0x
versions: ``CXX11=OFF`` (the default) *does not* require
``-std=c++11`` when compiling Ceres, *nor* does it require that any
client code using Ceres use ``-std=c++11``. However, this will
cause compile errors if any client code that uses Ceres also uses
C++11 (mismatched versions of ``shared_ptr`` & ``unordered_map``).
Enabling this option: ``CXX11=ON`` forces Ceres to use the C++11
versions of ``shared_ptr`` & ``unordered_map`` if they are
available, and thus imposes the requirement that all client code
using Ceres also compile with ``-std=c++11``. This requirement is
handled automatically through CMake target properties on the
exported Ceres target for CMake >= 2.8.12 (when it was introduced).
Thus, any client code which uses CMake will automatically be
compiled with ``-std=c++11``. **On CMake versions < 2.8.12, you
are responsible for ensuring that any code which uses Ceres is
compiled with** ``-std=c++11``.
On OS X 10.9+, Clang will use the C++11 versions of ``shared_ptr``
& ``unordered_map`` without ``-std=c++11`` and so this option does
not change the versions detected, although enabling it *will*
require that client code compile with ``-std=c++11``.
The following table summarises the effects of the ``CXX11`` option:
=================== ========== ================ ======================================
OS CXX11 Detected Version Ceres & client code require ``-std=c++11``
=================== ========== ================ ======================================
Linux (GCC & Clang) OFF tr1 **No**
Linux (GCC & Clang) ON std **Yes**
OS X 10.9+ OFF std **No**
OS X 10.9+ ON std **Yes**
=================== ========== ================ ======================================
The ``CXX11`` option does does not exist when using MSVC, as there
any new C++ features available are enabled by default, and there is
no analogue of ``-std=c++11``. It will however be available on
MinGW & CygWin, which can support ``-std=c++11``.
#. ``BUILD_SHARED_LIBS [Default: OFF]``: By default Ceres is built as
a static library, turn this ``ON`` to instead build Ceres as a
shared library.
#. ``EXPORT_BUILD_DIR [Default: OFF]``: By default Ceres is configured
solely for installation, and so must be installed in order for
clients to use it. Turn this ``ON`` to export Ceres' build
directory location into the `user's local CMake package registry
<http://www.cmake.org/cmake/help/v3.2/manual/cmake-packages.7.html#user-package-registry>`_
where it will be detected **without requiring installation** in a
client project using CMake when `find_package(Ceres)
<http://www.cmake.org/cmake/help/v3.2/command/find_package.html>`_
is invoked.
#. ``BUILD_DOCUMENTATION [Default: OFF]``: Use this to enable building
the documentation, requires `Sphinx <http://sphinx-doc.org/>`_ and
the `sphinx-better-theme
<https://pypi.python.org/pypi/sphinx-better-theme>`_ package
available from the Python package index. In addition, ``make
ceres_docs`` can be used to build only the documentation.
#. ``MSVC_USE_STATIC_CRT [Default: OFF]`` *Windows Only*: By default
Ceres will use the Visual Studio default, *shared* C-Run Time (CRT)
library. Turn this ``ON`` to use the *static* C-Run Time library
instead.
#. ``LIB_SUFFIX [Default: "64" on non-Debian/Arch based 64-bit Linux,
otherwise: ""]``: The suffix to append to the library install
directory, built from:
``${CMAKE_INSTALL_PREFIX}/lib${LIB_SUFFIX}``.
The filesystem hierarchy standard recommends that 64-bit systems
install native libraries to lib64 rather than lib. Most Linux
distributions follow this convention, but Debian and Arch based
distros do not. Note that the only generally sensible values for
``LIB_SUFFIX`` are "" and "64".
Although by default Ceres will auto-detect non-Debian/Arch based
64-bit Linux distributions and default ``LIB_SUFFIX`` to "64", this
can always be overridden by manually specifying LIB_SUFFIX using:
``-DLIB_SUFFIX=<VALUE>`` when invoking CMake.
Options controlling Ceres dependency locations
----------------------------------------------
Ceres uses the ``CMake`` `find_package
<http://www.cmake.org/cmake/help/v3.2/command/find_package.html>`_
function to find all of its dependencies using
``Find<DEPENDENCY_NAME>.cmake`` scripts which are either included in
Ceres (for most dependencies) or are shipped as standard with
``CMake`` (for ``LAPACK`` & ``BLAS``). These scripts will search all
of the "standard" install locations for various OSs for each
dependency. However, particularly for Windows, they may fail to find
the library, in this case you will have to manually specify its
installed location. The ``Find<DEPENDENCY_NAME>.cmake`` scripts
shipped with Ceres support two ways for you to do this:
#. Set the *hints* variables specifying the *directories* to search in
preference, but in addition, to the search directories in the
``Find<DEPENDENCY_NAME>.cmake`` script:
- ``<DEPENDENCY_NAME (CAPS)>_INCLUDE_DIR_HINTS``
- ``<DEPENDENCY_NAME (CAPS)>_LIBRARY_DIR_HINTS``
These variables should be set via ``-D<VAR>=<VALUE>``
``CMake`` arguments as they are not visible in the GUI.
#. Set the variables specifying the *explicit* include directory
and library file to use:
- ``<DEPENDENCY_NAME (CAPS)>_INCLUDE_DIR``
- ``<DEPENDENCY_NAME (CAPS)>_LIBRARY``
This bypasses *all* searching in the
``Find<DEPENDENCY_NAME>.cmake`` script, but validation is still
performed.
These variables are available to set in the ``CMake`` GUI. They are
visible in the *Standard View* if the library has not been found
(but the current Ceres configuration requires it), but are always
visible in the *Advanced View*. They can also be set directly via
``-D<VAR>=<VALUE>`` arguments to ``CMake``.
Building using custom BLAS & LAPACK installs
----------------------------------------------
If the standard find package scripts for ``BLAS`` & ``LAPACK`` which
ship with ``CMake`` fail to find the desired libraries on your system,
try setting ``CMAKE_LIBRARY_PATH`` to the path(s) to the directories
containing the ``BLAS`` & ``LAPACK`` libraries when invoking ``CMake``
to build Ceres via ``-D<VAR>=<VALUE>``. This should result in the
libraries being found for any common variant of each.
If you are building on an exotic system, or setting
``CMAKE_LIBRARY_PATH`` does not work, or is not appropriate for some
other reason, one option would be to write your own custom versions of
``FindBLAS.cmake`` & ``FindLAPACK.cmake`` specific to your
environment. In this case you must set ``CMAKE_MODULE_PATH`` to the
directory containing these custom scripts when invoking ``CMake`` to
build Ceres and they will be used in preference to the default
versions. However, in order for this to work, your scripts must
provide the full set of variables provided by the default scripts.
Also, if you are building Ceres with ``SuiteSparse``, the versions of
``BLAS`` & ``LAPACK`` used by ``SuiteSparse`` and Ceres should be the
same.
.. _section-using-ceres:
Using Ceres with CMake
======================
In order to use Ceres in client code with CMake using `find_package()
<http://www.cmake.org/cmake/help/v3.2/command/find_package.html>`_
then either:
#. Ceres must have been installed with ``make install``. If the
install location is non-standard (i.e. is not in CMake's default
search paths) then it will not be detected by default, see:
:ref:`section-local-installations`.
Note that if you are using a non-standard install location you
should consider exporting Ceres instead, as this will not require
any extra information to be provided in client code for Ceres to
be detected.
#. Or Ceres' build directory must have been exported by enabling the
``EXPORT_BUILD_DIR`` option when Ceres was configured.
As an example of how to use Ceres, to compile `examples/helloworld.cc
<https://ceres-solver.googlesource.com/ceres-solver/+/master/examples/helloworld.cc>`_
in a separate standalone project, the following CMakeList.txt can be
used:
.. code-block:: cmake
cmake_minimum_required(VERSION 2.8)
project(helloworld)
find_package(Ceres REQUIRED)
include_directories(${CERES_INCLUDE_DIRS})
# helloworld
add_executable(helloworld helloworld.cc)
target_link_libraries(helloworld ${CERES_LIBRARIES})
Irrespective of whether Ceres was installed or exported, if multiple
versions are detected, set: ``Ceres_DIR`` to control which is used.
If Ceres was installed ``Ceres_DIR`` should be the path to the
directory containing the installed ``CeresConfig.cmake`` file
(e.g. ``/usr/local/share/Ceres``). If Ceres was exported, then
``Ceres_DIR`` should be the path to the exported Ceres build
directory.
Specify Ceres components
-------------------------------------
You can specify particular Ceres components that you require (in order
for Ceres to be reported as found) when invoking
``find_package(Ceres)``. This allows you to specify, for example,
that you require a version of Ceres built with SuiteSparse support.
By definition, if you do not specify any components when calling
``find_package(Ceres)`` (the default) any version of Ceres detected
will be reported as found, irrespective of which components it was
built with.
The Ceres components which can be specified are:
#. ``LAPACK``: Ceres built using LAPACK (``LAPACK=ON``).
#. ``SuiteSparse``: Ceres built with SuiteSparse (``SUITESPARSE=ON``).
#. ``CXSparse``: Ceres built with CXSparse (``CXSPARSE=ON``).
#. ``EigenSparse``: Ceres built with Eigen's sparse Cholesky factorization
(``EIGENSPARSE=ON``).
#. ``SparseLinearAlgebraLibrary``: Ceres built with *at least one* sparse linear
algebra library. This is equivalent to ``SuiteSparse`` **OR** ``CXSparse``
**OR** ``EigenSparse``.
#. ``SchurSpecializations``: Ceres built with Schur specializations
(``SCHUR_SPECIALIZATIONS=ON``).
#. ``OpenMP``: Ceres built with OpenMP (``OPENMP=ON``).
#. ``C++11``: Ceres built with C++11 (``CXX11=ON``).
To specify one/multiple Ceres components use the ``COMPONENTS`` argument to
`find_package()
<http://www.cmake.org/cmake/help/v3.2/command/find_package.html>`_ like so:
.. code-block:: cmake
# Find a version of Ceres compiled with SuiteSparse & EigenSparse support.
#
# NOTE: This will report Ceres as **not** found if the detected version of
# Ceres was not compiled with both SuiteSparse & EigenSparse.
# Remember, if you have multiple versions of Ceres installed, you
# can use Ceres_DIR to specify which should be used.
find_package(Ceres REQUIRED COMPONENTS SuiteSparse EigenSparse)
Specify Ceres version
---------------------
Additionally, when CMake has found Ceres it can optionally check the package
version, if it has been specified in the `find_package()
<http://www.cmake.org/cmake/help/v3.2/command/find_package.html>`_
call. For example:
.. code-block:: cmake
find_package(Ceres 1.2.3 REQUIRED)
.. _section-local-installations:
Local installations
-------------------
If Ceres was installed in a non-standard path by specifying
``-DCMAKE_INSTALL_PREFIX="/some/where/local"``, then the user should
add the **PATHS** option to the ``find_package()`` command, e.g.,
.. code-block:: cmake
find_package(Ceres REQUIRED PATHS "/some/where/local/")
Note that this can be used to have multiple versions of Ceres
installed. However, particularly if you have only a single version of
Ceres which you want to use but do not wish to install to a system
location, you should consider exporting Ceres using the
``EXPORT_BUILD_DIR`` option instead of a local install, as exported
versions of Ceres will be automatically detected by CMake,
irrespective of their location.
Understanding the CMake Package System
----------------------------------------
Although a full tutorial on CMake is outside the scope of this guide,
here we cover some of the most common CMake misunderstandings that
crop up when using Ceres. For more detailed CMake usage, the
following references are very useful:
- The `official CMake tutorial <http://www.cmake.org/cmake-tutorial/>`_
Provides a tour of the core features of CMake.
- `ProjectConfig tutorial
<http://www.cmake.org/Wiki/CMake/Tutorials/How_to_create_a_ProjectConfig.cmake_file>`_
and the `cmake-packages documentation
<http://www.cmake.org/cmake/help/git-master/manual/cmake-packages.7.html>`_
Cover how to write a ``ProjectConfig.cmake`` file, discussed below,
for your own project when installing or exporting it using CMake.
It also covers how these processes in conjunction with
``find_package()`` are actually handled by CMake. The
`ProjectConfig tutorial
<http://www.cmake.org/Wiki/CMake/Tutorials/How_to_create_a_ProjectConfig.cmake_file>`_
is the older style, currently used by Ceres for compatibility with
older versions of CMake.
.. NOTE :: **Targets in CMake.**
All libraries and executables built using CMake are represented as
*targets* created using `add_library()
<http://www.cmake.org/cmake/help/v3.2/command/add_library.html>`_
and `add_executable()
<http://www.cmake.org/cmake/help/v3.2/command/add_executable.html>`_.
Targets encapsulate the rules and dependencies (which can be other
targets) required to build or link against an object. This allows
CMake to implicitly manage dependency chains. Thus it is
sufficient to tell CMake that a library target: ``B`` depends on a
previously declared library target ``A``, and CMake will
understand that this means that ``B`` also depends on all of the
public dependencies of ``A``.
When a project like Ceres is installed using CMake, or its build
directory is exported into the local CMake package registry (see
:ref:`section-install-vs-export`), in addition to the public headers
and compiled libraries, a set of CMake-specific project configuration
files are also installed to: ``<INSTALL_ROOT>/share/Ceres`` (if Ceres
is installed), or created in the build directory (if Ceres' build
directory is exported). When `find_package
<http://www.cmake.org/cmake/help/v3.2/command/find_package.html>`_ is
invoked, CMake checks various standard install locations (including
``/usr/local`` on Linux & UNIX systems), and the local CMake package
registry for CMake configuration files for the project to be found
(i.e. Ceres in the case of ``find_package(Ceres)``). Specifically it
looks for:
- ``<PROJECT_NAME>Config.cmake`` (or
``<lower_case_project_name>-config.cmake``)
Which is written by the developers of the project, and is
configured with the selected options and installed locations when
the project is built and defines the CMake variables:
``<PROJECT_NAME>_INCLUDE_DIRS`` & ``<PROJECT_NAME>_LIBRARIES``
which are used by the caller to import the project.
The ``<PROJECT_NAME>Config.cmake`` typically includes a second file
installed to the same location:
- ``<PROJECT_NAME>Targets.cmake``
Which is autogenerated by CMake as part of the install process and defines
**imported targets** for the project in the caller's CMake scope.
An **imported target** contains the same information about a library
as a CMake target that was declared locally in the current CMake
project using ``add_library()``. However, imported targets refer to
objects that have already been built by a different CMake project.
Principally, an imported target contains the location of the compiled
object and all of its public dependencies required to link against it.
Any locally declared target can depend on an imported target, and
CMake will manage the dependency chain, just as if the imported target
had been declared locally by the current project.
Crucially, just like any locally declared CMake target, an imported target is
identified by its **name** when adding it as a dependency to another target.
Thus, if in a project using Ceres you had the following in your CMakeLists.txt:
.. code-block:: cmake
find_package(Ceres REQUIRED)
message("CERES_LIBRARIES = ${CERES_LIBRARIES}")
You would see the output: ``CERES_LIBRARIES = ceres``. **However**,
here ``ceres`` is an **imported target** created when
``CeresTargets.cmake`` was read as part of ``find_package(Ceres
REQUIRED)``. It does **not** refer (directly) to the compiled Ceres
library: ``libceres.a/so/dylib/lib``. This distinction is important,
as depending on the options selected when it was built, Ceres can have
public link dependencies which are encapsulated in the imported target
and automatically added to the link step when Ceres is added as a
dependency of another target by CMake. In this case, linking only
against ``libceres.a/so/dylib/lib`` without these other public
dependencies would result in a linker error.
Note that this description applies both to projects that are
**installed** using CMake, and to those whose **build directory is
exported** using `export()
<http://www.cmake.org/cmake/help/v3.2/command/export.html>`_ (instead
of `install()
<http://www.cmake.org/cmake/help/v3.2/command/install.html>`_). Ceres
supports both installation and export of its build directory if the
``EXPORT_BUILD_DIR`` option is enabled, see
:ref:`section-customizing`.
.. _section-install-vs-export:
Installing a project with CMake vs Exporting its build directory
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
When a project is **installed**, the compiled libraries and headers
are copied from the source & build directory to the install location,
and it is these copied files that are used by any client code. When a
project's build directory is **exported**, instead of copying the
compiled libraries and headers, CMake creates an entry for the project
in the `user's local CMake package registry
<http://www.cmake.org/cmake/help/v3.2/manual/cmake-packages.7.html#user-package-registry>`_,
``<USER_HOME>/.cmake/packages`` on Linux & OS X, which contains the
path to the project's build directory which will be checked by CMake
during a call to ``find_package()``. The effect of which is that any
client code uses the compiled libraries and headers in the build
directory directly, **thus not requiring the project to be installed
to be used**.
Installing / Exporting a project that uses Ceres
--------------------------------------------------
As described in `Understanding the CMake Package System`_, the contents of
the ``CERES_LIBRARIES`` variable is the **name** of an imported target which
represents Ceres. If you are installing / exporting your *own* project which
*uses* Ceres, it is important to understand that:
**Imported targets are not (re)exported when a project which imported them is
exported**.
Thus, when a project ``Foo`` which uses Ceres is exported, its list of
dependencies as seen by another project ``Bar`` which imports ``Foo``
via: ``find_package(Foo REQUIRED)`` will contain: ``ceres``. However,
the definition of ``ceres`` as an imported target is **not
(re)exported** when Foo is exported. Hence, without any additional
steps, when processing ``Bar``, ``ceres`` will not be defined as an
imported target. Thus, when processing ``Bar``, CMake will assume
that ``ceres`` refers only to: ``libceres.a/so/dylib/lib`` (the
compiled Ceres library) directly if it is on the current list of
search paths. In which case, no CMake errors will occur, but ``Bar``
will not link properly, as it does not have the required public link
dependencies of Ceres, which are stored in the imported target
defintion.
The solution to this is for ``Foo`` (i.e., the project that uses
Ceres) to invoke ``find_package(Ceres)`` in ``FooConfig.cmake``, thus
``ceres`` will be defined as an imported target when CMake processes
``Bar``. An example of the required modifications to
``FooConfig.cmake`` are show below:
.. code-block:: cmake
# Importing Ceres in FooConfig.cmake using CMake 2.8.x style.
#
# When configure_file() is used to generate FooConfig.cmake from
# FooConfig.cmake.in, @Ceres_DIR@ will be replaced with the current
# value of Ceres_DIR being used by Foo. This should be passed as a hint
# when invoking find_package(Ceres) to ensure that the same install of
# Ceres is used as was used to build Foo.
set(CERES_DIR_HINTS @Ceres_DIR@)
# Forward the QUIET / REQUIRED options.
if (Foo_FIND_QUIETLY)
find_package(Ceres QUIET HINTS ${CERES_DIR_HINTS})
elseif (Foo_FIND_REQUIRED)
find_package(Ceres REQUIRED HINTS ${CERES_DIR_HINTS})
else ()
find_package(Ceres HINTS ${CERES_DIR_HINTS})
endif()
.. code-block:: cmake
# Importing Ceres in FooConfig.cmake using CMake 3.x style.
#
# In CMake v3.x, the find_dependency() macro exists to forward the REQUIRED
# / QUIET parameters to find_package() when searching for dependencies.
#
# Note that find_dependency() does not take a path hint, so if Ceres was
# installed in a non-standard location, that location must be added to
# CMake's search list before this call.
include(CMakeFindDependencyMacro)
find_dependency(Ceres)