如何安裝Sophus李代數庫

Sophus庫有模板類庫和非模板類庫兩個版本，本文選擇的是非模板類庫。
開始使用Sophus庫時會碰到下面的錯誤，說明Sophus沒有正確編譯。

  By not providing "FindSophus.cmake" in CMAKE_MODULE_PATH this project has
  asked CMake to find a package configuration file provided by "Sophus", but
  CMake did not find one.

  Could not find a package configuration file provided by "Sophus" with any
  of the following names:

    SophusConfig.cmake
    sophus-config.cmake

  Add the installation prefix of "Sophus" to CMAKE_PREFIX_PATH or set
  "Sophus_DIR" to a directory containing one of the above files.  If "Sophus"
  provides a separate development package or SDK, be sure it has been
  installed.


-- Configuring incomplete, errors occurred!

Sophus庫本身是一個cmake工程，使用以下命令對它進行編譯（Sophus庫只需編譯，無需安裝）。

可以通過輸入以下命令獲得並安裝非模板類的Sophus庫：

git clone http://github.com/strasdat/Sophus.git
cd Sophus
git checkout a621ff
mkdir build
cd build
cmake ..
make