Fixing issue pointed out by CRAN

Author: gvegayon

NEWS.md

@@ -4,6 +4,8 @@
 
 * Small changes in C++ formatting and conventions to please CRAN.
 
+* Fixes a bug when using the stationary value of the root node probability.
+
 
 # Changes in aphylo version 0.3-0
 

src/TreeData.hpp

@@ -224,7 +224,7 @@ class TreeData {
     for (auto iter = types.begin(); iter != types.end(); ++iter) {
 
       if (*iter == 0u) {
-        this->prop_type_d =+ increments;
+        this->prop_type_d += increments;
       } else if (*iter != 1u)
         throw std::invalid_argument("Values in the type of node should be either 0 or 1.");