Adding checks to ensure that the column rank is not trivially deficie…

…nt in sparse LeastSquares/Ridge/Tikhonov

src/sparse_direct/numeric/LeastSquares.cpp

@@ -24,6 +24,8 @@ void LeastSquares
         if( orientation != NORMAL && A.Width() != Y.Height() )
             LogicError("Width of A and height of Y must match");
     )
+    if( A.Width() > A.Height() )
+        LogicError("LeastSquares currently assumes height(A) >= width(A)");
     DistSparseMatrix<F> C(A.Comm());
     if( orientation == NORMAL )
     {

src/sparse_direct/numeric/Ridge.cpp

@@ -21,6 +21,8 @@ void Ridge
         if( A.Height() != Y.Height() )
             LogicError("Heights of A and Y must match");
     )
+    if( A.Width() > A.Height() )
+        LogicError("Ridge currently assumes height(A) >= width(A)");
     const Int n = A.Width();
     DistSparseMatrix<F> C(A.Comm());
     Herk( LOWER, ADJOINT, Base<F>(1), A, C );

src/sparse_direct/numeric/Tikhonov.cpp

@@ -21,6 +21,8 @@ void Tikhonov
         if( A.Height() != Y.Height() )
             LogicError("Heights of A and Y must match");
     )
+    if( A.Width() > A.Height() )
+        LogicError("Tikhonov currently assumes height(A) >= width(A)");
     const Int n = A.Width();
     DistSparseMatrix<F> C(A.Comm());
     Herk( LOWER, ADJOINT, Base<F>(1), A, C );

vagrant/README.md

@@ -1,4 +1,4 @@
 This folder will slowly accumulate various [Vagrantfiles](http://vagrantup.com) 
 for developing Elemental. For instance, to load a 32-bit development environment
-for Elemental within Ubuntu 13.10 (Saucy), simply run: 
-``cd saucy32; vagrant up``.
+for Elemental within Ubuntu 14.04 (Trusty), simply run: 
+``cd trusty32; vagrant up``.