add simple example code

This builds an external application against Kassiopeia libraries.

Examples/.gitignore

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+Makefile
+build.ninja
+/ks-particles-example

Examples/CMakeLists.txt

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+cmake_minimum_required(VERSION 3.0)
+
+# Name your project
+project(Kassiopeia-Examples)
+
+message("CMake prefix path: ${CMAKE_PREFIX_PATH}")
+
+find_package(Boost REQUIRED COMPONENTS filesystem)
+find_package(VTK)
+if(VTK_FOUND)
+    include(${VTK_USE_FILE})
+endif(VTK_FOUND)
+
+# Don't forget to set CMAKE_PREFIX_PATH to your Kasper installation folder
+# before executing cmake. That way, CMake will be able to find the KaLi installation.
+find_package(Kassiopeia REQUIRED)
+find_package(KEMField REQUIRED)
+find_package(KGeoBag REQUIRED)
+
+# Set the default install prefix (you don't need to remember this)
+if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
+    get_filename_component(BUILD_PARENT_DIR ${CMAKE_BINARY_DIR} PATH)
+    set(CMAKE_INSTALL_PREFIX "${BUILD_PARENT_DIR}/install" CACHE PATH "Install path prefix, prepended onto install directories." FORCE)
+endif()
+
+set( CMAKE_CXX_STANDARD 14 )
+set( CMAKE_CXX_STANDARD_REQUIRED ON )
+set( CMAKE_CXX_EXTENSIONS OFF )
+
+# Define your include directories
+include_directories (
+    ${Kassiopeia_INCLUDE_DIRS}
+    ${KEMField_INCLUDE_DIRS}
+    ${KGeoBag_INCLUDE_DIRS}
+)
+
+SET(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
+
+#----------------------------------------
+# Build libraries and ROOT dictionaries
+#----------------------------------------
+
+# not needed for this example
+
+#----------------------------------------
+# Build the executable
+#----------------------------------------
+
+set( EXECUTABLES
+        ks-particles-example
+)
+
+foreach(EXECUTABLE ${EXECUTABLES})
+    add_executable(${EXECUTABLE} ${EXECUTABLE}.cxx)
+    target_link_libraries (${EXECUTABLE} ${Kassiopeia_LIBRARIES})
+endforeach()
+
+# Define a cmake install target
+install(TARGETS ${EXECUTABLES} DESTINATION ${CMAKE_INSTALL_PREFIX})

Examples/ks-particles-example.cxx

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+/**
+ * @file ks-particles.cxx
+ *
+ * @date 22.07.2020
+ * @author Jan Behrens <[email protected]>
+ */
+
+// Kasper Common includes
+#include <KException.h>
+#include <KLogger.h>
+#include <KMessage.h>
+
+// Kassiopeia includes
+#include <KSMainMessage.h>
+#include <KSParticle.h>
+#include <KSParticleFactory.h>
+
+KLOGGER("kassiopeia.examples");
+
+using namespace katrin;
+using namespace Kassiopeia;
+
+int main(int argc, char** argv)
+{
+    // set message verbosity
+    KMessageTable::GetInstance().SetTerminalVerbosity(eDebug);
+    KMessageTable::GetInstance().SetLogVerbosity(eDebug);
+
+    // create an instance of the particle factory
+    KSParticleFactory& tFactory = KSParticleFactory::GetInstance();
+
+    // generate particles and print information
+    for (int i = 1; i < argc; i++) {
+        KSParticle *tParticle;
+
+        mainmsg(eNormal) << "Creating a particle with id: " << argv[i] << eom;
+
+        try {
+            try {
+                // try using a numeric particle id
+                long tPID = std::stol(argv[i]);
+                tParticle = tFactory.Create(tPID);
+            }
+            catch (std::invalid_argument) {
+                // if it fails, try to use a string id
+                std::string tStringID(argv[i]);
+                tParticle = tFactory.StringCreate(tStringID);
+            }
+        }
+        catch (KException) {
+            continue;
+        }
+
+        tParticle->Print();
+
+        delete tParticle;
+    }
+
+    return 0;
+}