* fix super nasty bug: vector.maxCoeff(&index) didn't work when 'vector'

was a row-vector. Fixed by splitting the vector version from the matrix version.
* add unit test, the visitors weren't covered by any test!!

Eigen/src/Core/MatrixBase.h

@@ -675,8 +675,11 @@ template<typename Derived> class MatrixBase
     typename ei_traits<Derived>::Scalar minCoeff() const;
     typename ei_traits<Derived>::Scalar maxCoeff() const;
 
-    typename ei_traits<Derived>::Scalar minCoeff(int* row, int* col = 0) const;
+    typename ei_traits<Derived>::Scalar minCoeff(int* row, int* col) const;
-    typename ei_traits<Derived>::Scalar maxCoeff(int* row, int* col = 0) const;
+    typename ei_traits<Derived>::Scalar maxCoeff(int* row, int* col) const;
+
+    typename ei_traits<Derived>::Scalar minCoeff(int* index) const;
+    typename ei_traits<Derived>::Scalar maxCoeff(int* index) const;
 
     template<typename BinaryOp>
     typename ei_result_of<BinaryOp(typename ei_traits<Derived>::Scalar)>::type

Eigen/src/Core/Visitor.h

@@ -164,7 +164,7 @@ struct ei_functor_traits<ei_max_coeff_visitor<Scalar> > {
 /** \returns the minimum of all coefficients of *this
   * and puts in *row and *col its location.
   *
-  * \sa MatrixBase::maxCoeff(int*,int*), MatrixBase::visitor(), MatrixBase::minCoeff()
+  * \sa MatrixBase::minCoeff(int*), MatrixBase::maxCoeff(int*,int*), MatrixBase::visitor(), MatrixBase::minCoeff()
   */
 template<typename Derived>
 typename ei_traits<Derived>::Scalar
@@ -177,6 +177,22 @@ MatrixBase<Derived>::minCoeff(int* row, int* col) const
   return minVisitor.res;
 }
 
+/** \returns the minimum of all coefficients of *this
+  * and puts in *index its location.
+  *
+  * \sa MatrixBase::minCoeff(int*,int*), MatrixBase::maxCoeff(int*,int*), MatrixBase::visitor(), MatrixBase::minCoeff()
+  */
+template<typename Derived>
+typename ei_traits<Derived>::Scalar
+MatrixBase<Derived>::minCoeff(int* index) const
+{
+  EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
+  ei_min_coeff_visitor<Scalar> minVisitor;
+  this->visit(minVisitor);
+  *index = (RowsAtCompileTime==1) ? minVisitor.col : minVisitor.row;
+  return minVisitor.res;
+}
+
 /** \returns the maximum of all coefficients of *this
   * and puts in *row and *col its location.
   *
@@ -193,5 +209,20 @@ MatrixBase<Derived>::maxCoeff(int* row, int* col) const
   return maxVisitor.res;
 }
 
+/** \returns the maximum of all coefficients of *this
+  * and puts in *index its location.
+  *
+  * \sa MatrixBase::maxCoeff(int*,int*), MatrixBase::minCoeff(int*,int*), MatrixBase::visitor(), MatrixBase::maxCoeff()
+  */
+template<typename Derived>
+typename ei_traits<Derived>::Scalar
+MatrixBase<Derived>::maxCoeff(int* index) const
+{
+  EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
+  ei_max_coeff_visitor<Scalar> maxVisitor;
+  this->visit(maxVisitor);
+  *index = (RowsAtCompileTime==1) ? maxVisitor.col : maxVisitor.row;
+  return maxVisitor.res;
+}
 
 #endif // EIGEN_VISITOR_H

test/CMakeLists.txt

@@ -94,6 +94,7 @@ ei_add_test(basicstuff)
 ei_add_test(linearstructure)
 ei_add_test(cwiseop)
 ei_add_test(redux)
+ei_add_test(visitor)
 ei_add_test(product_small)
 ei_add_test(product_large ${EI_OFLAG})
 ei_add_test(product_extra ${EI_OFLAG})

test/redux.cpp

@@ -120,7 +120,7 @@ void test_redux()
     CALL_SUBTEST( matrixRedux(MatrixXi(8, 12)) );
   }
   for(int i = 0; i < g_repeat; i++) {
-    CALL_SUBTEST( vectorRedux(VectorXf(5)) );
+    CALL_SUBTEST( vectorRedux(VectorX4f()) );
     CALL_SUBTEST( vectorRedux(VectorXd(10)) );
     CALL_SUBTEST( vectorRedux(VectorXf(33)) );
   }

test/visitor.cpp

@@ -0,0 +1,131 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2008 Benoit Jacob <jacob.benoit.1@gmail.com>
+//
+// Eigen is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 3 of the License, or (at your option) any later version.
+//
+// Alternatively, you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of
+// the License, or (at your option) any later version.
+//
+// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License and a copy of the GNU General Public License along with
+// Eigen. If not, see <http://www.gnu.org/licenses/>.
+
+#include "main.h"
+
+template<typename MatrixType> void matrixVisitor(const MatrixType& p)
+{
+  typedef typename MatrixType::Scalar Scalar;
+
+  int rows = p.rows();
+  int cols = p.cols();
+
+  // construct a random matrix where all coefficients are different
+  MatrixType m;
+  m = MatrixType::Random(rows, cols);
+  for(int i = 0; i < m.size(); i++)
+    for(int i2 = 0; i2 < i; i2++)
+      while(m(i) == m(i2)) // yes, ==
+        m(i) = ei_random<Scalar>();
+  
+  Scalar minc = Scalar(1000), maxc = Scalar(-1000);
+  int minrow,mincol,maxrow,maxcol;
+  for(int j = 0; j < cols; j++)
+  for(int i = 0; i < rows; i++)
+  {
+    if(m(i,j) < minc)
+    {
+      minc = m(i,j);
+      minrow = i;
+      mincol = j;
+    }
+    if(m(i,j) > maxc)
+    {
+      maxc = m(i,j);
+      maxrow = i;
+      maxcol = j;
+    }
+  }
+  int eigen_minrow, eigen_mincol, eigen_maxrow, eigen_maxcol;
+  Scalar eigen_minc, eigen_maxc;
+  eigen_minc = m.minCoeff(&eigen_minrow,&eigen_mincol);
+  eigen_maxc = m.maxCoeff(&eigen_maxrow,&eigen_maxcol);
+  VERIFY(minrow == eigen_minrow);
+  VERIFY(maxrow == eigen_maxrow);
+  VERIFY(mincol == eigen_mincol);
+  VERIFY(maxcol == eigen_maxcol);
+  VERIFY_IS_APPROX(minc, eigen_minc);
+  VERIFY_IS_APPROX(maxc, eigen_maxc);
+  VERIFY_IS_APPROX(minc, m.minCoeff());
+  VERIFY_IS_APPROX(maxc, m.maxCoeff());
+}
+
+template<typename VectorType> void vectorVisitor(const VectorType& w)
+{
+  typedef typename VectorType::Scalar Scalar;
+
+  int size = w.size();
+
+  // construct a random vector where all coefficients are different
+  VectorType v;
+  v = VectorType::Random(size);
+  for(int i = 0; i < size; i++)
+    for(int i2 = 0; i2 < i; i2++)
+      while(v(i) == v(i2)) // yes, ==
+        v(i) = ei_random<Scalar>();
+  
+  Scalar minc = Scalar(1000), maxc = Scalar(-1000);
+  int minidx,maxidx;
+  for(int i = 0; i < size; i++)
+  {
+    if(v(i) < minc)
+    {
+      minc = v(i);
+      minidx = i;
+    }
+    if(v(i) > maxc)
+    {
+      maxc = v(i);
+      maxidx = i;
+    }
+  }
+  int eigen_minidx, eigen_maxidx;
+  Scalar eigen_minc, eigen_maxc;
+  eigen_minc = v.minCoeff(&eigen_minidx);
+  eigen_maxc = v.maxCoeff(&eigen_maxidx);
+  VERIFY(minidx == eigen_minidx);
+  VERIFY(maxidx == eigen_maxidx);
+  VERIFY_IS_APPROX(minc, eigen_minc);
+  VERIFY_IS_APPROX(maxc, eigen_maxc);
+  VERIFY_IS_APPROX(minc, v.minCoeff());
+  VERIFY_IS_APPROX(maxc, v.maxCoeff());
+}
+
+void test_visitor()
+{
+  for(int i = 0; i < g_repeat; i++) {
+    CALL_SUBTEST( matrixVisitor(Matrix<float, 1, 1>()) );
+    CALL_SUBTEST( matrixVisitor(Matrix2f()) );
+    CALL_SUBTEST( matrixVisitor(Matrix4d()) );
+    CALL_SUBTEST( matrixVisitor(MatrixXd(8, 12)) );
+    CALL_SUBTEST( matrixVisitor(Matrix<double,Dynamic,Dynamic,RowMajor>(20, 20)) );
+    CALL_SUBTEST( matrixVisitor(MatrixXi(8, 12)) );
+  }
+  for(int i = 0; i < g_repeat; i++) {
+    CALL_SUBTEST( vectorVisitor(Vector4f()) );
+    CALL_SUBTEST( vectorVisitor(VectorXd(10)) );
+    CALL_SUBTEST( vectorVisitor(RowVectorXd(10)) );
+    CALL_SUBTEST( vectorVisitor(VectorXf(33)) );
+  }
+}