added TreeTest (bifurcation)

src/phylogeny/Tree.hpp

@@ -692,6 +692,46 @@ Tree<TreeNodeType>::~Tree()
 	// TODO Auto-generated destructor stub
 }
 
+/**
+ * \brief Checks if a tree is strictly bifurcating.
+ * \details For a strictly bifurcating tree every inner node can just have exactly two child nodes;
+ * based on the throwError parameter the function either returns boolean (true = tree is strictly bifurcating)
+ * or throws at first non-bifurcating node a runtime error and quits.
+ *
+ * \param tree tree to be checked for bifurcation
+ * \param throwError if set to true a runtime error is thrown at first non-bifurcating node instead of a false return value
+ *
+ * \relates Tree
+ */
+template <typename DataType>
+bool isBifurcatingTree(const Tree<DataType> &tree, bool throwError = false) {
+	bool bifur = true;
+
+	for (auto cNode = tree.postorderBegin(); cNode != tree.postorderEnd(); ++cNode) {
+		if (!cNode->isLeaf()) {
+			unsigned int cnum = cNode->nChildren();
+			if (cnum == 1) {
+				if (throwError) {
+					throw std::runtime_error("Error: Not a bifurcating tree. Node with just one child detected - Node-ID " + cNode->id);
+				}
+				else {
+					bifur = false;
+				}
+			}
+			if (cnum > 2) {
+				if (throwError) {
+					throw std::runtime_error("Error: Not a bifurcating tree. Node with more than two childs detected - Node-ID " + cNode->id);
+				}
+				else {
+					bifur = false;
+				}
+			}
+		}
+	}
+
+	return bifur;
+}
+
 /** @} */ // PhyloGroup
 
 } /* namespace BioSeqDataLib */

tests/phylogeny/TreeTest.hpp

@@ -33,10 +33,38 @@
 
 #include "../../src/utility/Matrix.hpp"
 #include "../../src/phylogeny/Tree.hpp"
-
+#include "../../src/phylogeny/PhylogeneticTree.hpp"
 
 BOOST_AUTO_TEST_SUITE(Tree_Test)
 
+BOOST_AUTO_TEST_CASE( Bifurcation_Test )
+{
+    // bifurcating tree
+    BioSeqDataLib::PhylogeneticTree<int> bifurTree;
+    bifurTree.str2tree("(((C:2.000000,(A:1.000000,B:3.000000)),(D:1.000000,E:1.500000)),OG);"); // bifurcation
+
+    bool bifurTreeBifur = BioSeqDataLib::isBifurcatingTree(bifurTree);
+    BOOST_CHECK_EQUAL(bifurTreeBifur, true);
+
+    // monofurcating tree
+    BioSeqDataLib::PhylogeneticTree<int> monofurTree;
+    monofurTree.str2tree("((((C),(A,B)),(D,E)),OG);"); // monofurcation
+
+    bool monoTreeBifur = BioSeqDataLib::isBifurcatingTree(monofurTree);
+    BOOST_CHECK_EQUAL(monoTreeBifur, false);
+
+    BOOST_CHECK_THROW(BioSeqDataLib::isBifurcatingTree(monofurTree, true), std::runtime_error);
+
+    // multifurcating tree
+    BioSeqDataLib::PhylogeneticTree<int> multifurTree;
+    multifurTree.str2tree("(((C,B,A),(D,E)),OG);"); // multifurcation
+
+    bool multiTreeBifur = BioSeqDataLib::isBifurcatingTree(multifurTree);
+    BOOST_CHECK_EQUAL(multiTreeBifur, false);
+
+    BOOST_CHECK_THROW(BioSeqDataLib::isBifurcatingTree(multifurTree, true), std::runtime_error);
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 #endif /* TREETEST_HPP_ */