fix set() for EigenVector

MathLib/LinAlg/BLAS.cpp

@@ -225,9 +225,9 @@ namespace MathLib { namespace BLAS
 
 // Vector
 
-void set(EigenVector const& x, double const a)
+void set(EigenVector& x, double const a)
 {
-    x.getRawVector() = a;
+    x.getRawVector().setConstant(a);
 }
 
 void copy(EigenVector const& x, EigenVector& y)