resolve conflits and merge PR 196

CMakeLists.txt

@@ -34,11 +34,15 @@ if (OPENMP_FOUND)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}")
 endif ()
 
+if (USE_CUDA AND USE_EIGEN)
+    message (FATAL_ERROR "CUDA and Eigen are mutually exclusive. Please specify either USE_CUDA or USE_EIGEN, not both.")
+endif ()
+
 if (USE_CUDA)
     message("Compile with CUDA")
     find_package(CUDA REQUIRED QUIET)
     set(CUDA_NVCC_FLAGS ${CUDA_NVCC_FLAGS} -std=c++11 -Wno-deprecated-gpu-targets)
-    set(LINK_LIBRARY ${CUDA_cusparse_LIBRARY})
+    list(APPEND LINK_LIBRARY ${CUDA_cusparse_LIBRARY})
 
     # Correct error for GCC 5 and CUDA 7.5
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D_MWAITXINTRIN_H_INCLUDED -D_FORCE_INLINES")
@@ -47,8 +51,15 @@ else ()
 endif ()
 
 if (USE_EIGEN)
-    message("using Eigen for acceleration")
-    include_directories(${PROJECT_SOURCE_DIR}/eigen)
+    find_package (Eigen3 3.3 NO_MODULE)
+    if (Eigen3_FOUND)
+        message("using external Eigen3 for acceleration")
+        include_directories(${EIGEN3_INCLUDE_DIR})
+        list(APPEND LINK_LIBRARY Eigen3::Eigen)
+    else ()
+        message("using internal Eigen3 for acceleration")
+        include_directories(${PROJECT_SOURCE_DIR}/eigen)
+    endif ()
     add_compile_options("-march=native")
 endif ()
 

cmake/thundersvmConfig.cmake.in

@@ -1,4 +1,10 @@
 @PACKAGE_INIT@
 
+if (@USE_EIGEN@)
+    if (@Eigen3_FOUND@)
+        find_dependency(Eigen3)
+    endif ()
+endif()
+
 include("${CMAKE_CURRENT_LIST_DIR}/@PROJECT_NAME@Targets.cmake")
 check_required_components("@PROJECT_NAME@")