Sparse module: add a more flexible SparseMatrix::fillrand() function

which allows to fill a matrix with random inner coordinates (makes sense
only when a very few coeffs are inserted per col/row)

Eigen/src/Sparse/SparseMatrix.h

@@ -131,6 +131,10 @@ class SparseMatrix
     /** \returns the number of non zero coefficients */
     inline int nonZeros() const  { return m_data.size(); }
 
+    /** Initializes the filling process of \c *this.
+      * \param reserveSize approximate number of nonzeros
+      * Note that the matrix \c *this is zero-ed.
+      */
     inline void startFill(int reserveSize = 1000)
     {
       m_data.clear();
@@ -139,13 +143,16 @@ class SparseMatrix
         m_outerIndex[i] = 0;
     }
 
+    /**
+      */
     inline Scalar& fill(int row, int col)
     {
       const int outer = RowMajor ? row : col;
       const int inner = RowMajor ? col : row;
-//       std::cout << " fill " << outer << "," << inner << "\n";
+
       if (m_outerIndex[outer+1]==0)
       {
+        // we start a new inner vector
         int i = outer;
         while (i>=0 && m_outerIndex[i]==0)
         {
@@ -162,6 +169,42 @@ class SparseMatrix
       return m_data.value(id);
     }
 
+    /** Like fill() but with random inner coordinates.
+      */
+    inline Scalar& fillrand(int row, int col)
+    {
+      const int outer = RowMajor ? row : col;
+      const int inner = RowMajor ? col : row;
+
+      if (m_outerIndex[outer+1]==0)
+      {
+        // we start a new inner vector
+        // nothing special to do here
+        int i = outer;
+        while (i>=0 && m_outerIndex[i]==0)
+        {
+          m_outerIndex[i] = m_data.size();
+          --i;
+        }
+        m_outerIndex[outer+1] = m_outerIndex[outer];
+      }
+      //
+      assert(m_outerIndex[outer+1] == m_data.size() && "invalid outer index");
+      int startId = m_outerIndex[outer];
+      int id = m_outerIndex[outer+1]-1;
+      m_outerIndex[outer+1]++;
+      m_data.resize(id+2);
+
+      while ( (id >= startId) && (m_data.index(id) > inner) )
+      {
+        m_data.index(id+1) = m_data.index(id);
+        m_data.value(id+1) = m_data.value(id);
+        --id;
+      }
+      m_data.index(id+1) = inner;
+      return (m_data.value(id+1) = 0);
+    }
+
     inline void endFill()
     {
       int size = m_data.size();

Eigen/src/Sparse/SparseMatrixBase.h

@@ -63,8 +63,8 @@ class SparseMatrixBase : public MatrixBase<Derived>
     inline Derived& operator=(const MatrixBase<OtherDerived>& other)
     {
 //       std::cout << "Derived& operator=(const MatrixBase<OtherDerived>& other)\n";
-      const bool transpose = (Flags & RowMajorBit) != (OtherDerived::Flags & RowMajorBit);
+      //const bool transpose = (Flags & RowMajorBit) != (OtherDerived::Flags & RowMajorBit);
-      ei_assert((!transpose) && "the transpose operation is supposed to be handled in SparseMatrix::operator=");
+      ei_assert((!((Flags & RowMajorBit) != (OtherDerived::Flags & RowMajorBit))) && "the transpose operation is supposed to be handled in SparseMatrix::operator=");
       const int outerSize = other.outerSize();
       //typedef typename ei_meta_if<transpose, LinkedVectorMatrix<Scalar,Flags&RowMajorBit>, Derived>::ret TempType;
       // thanks to shallow copies, we always eval to a tempary

Eigen/src/Sparse/SparseProduct.h

@@ -138,8 +138,8 @@ struct ei_sparse_product_selector<Lhs,Rhs,ResultType,ColMajor,ColMajor,ColMajor>
     // make sure to call innerSize/outerSize since we fake the storage order.
     int rows = lhs.innerSize();
     int cols = rhs.outerSize();
-    int size = lhs.outerSize();
+    //int size = lhs.outerSize();
-    ei_assert(size == rhs.innerSize());
+    ei_assert(lhs.outerSize() == rhs.innerSize());
 
     // allocate a temporary buffer
     AmbiVector<Scalar> tempVector(rows);

test/sparse_basic.cpp

@@ -153,6 +153,26 @@ template<typename Scalar> void sparse_basic(int rows, int cols)
     #ifdef _SPARSE_HASH_MAP_H_
     VERIFY(( test_random_setter<RandomSetter<SparseMatrix<Scalar>, GoogleSparseHashMapTraits> >(m,refMat,nonzeroCoords) ));
     #endif
+
+    // test fillrand
+    {
+      DenseMatrix m1(rows,cols);
+      m1.setZero();
+      SparseMatrix<Scalar> m2(rows,cols);
+      m2.startFill();
+      for (int j=0; j<cols; ++j)
+      {
+        for (int k=0; k<rows/2; ++k)
+        {
+          int i = ei_random<int>(0,rows-1);
+          if (m1.coeff(i,j)==Scalar(0))
+            m2.fillrand(i,j) = m1(i,j) = ei_random<Scalar>();
+        }
+      }
+      m2.endFill();
+      std::cerr << m1 << "\n\n" << m2 << "\n";
+      VERIFY_IS_APPROX(m1,m2);
+    }
 //   {
 //     m.setZero();
 //     VERIFY_IS_NOT_APPROX(m, refMat);