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diff --git a/src/Coxeter_triangulation/include/gudhi/Functions/Linear_transformation.h b/src/Coxeter_triangulation/include/gudhi/Functions/Linear_transformation.h
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+/*    This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT.
+ *    See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details.
+ *    Author(s):       Siargey Kachanovich
+ *
+ *    Copyright (C) 2019 Inria
+ *
+ *    Modification(s):
+ *      - YYYY/MM Author: Description of the modification
+ */
+
+#ifndef FUNCTIONS_LINEAR_TRANSFORMATION_H_
+#define FUNCTIONS_LINEAR_TRANSFORMATION_H_
+
+#include <cstdlib>  // for std::size_t
+
+#include <Eigen/Dense>
+
+namespace Gudhi {
+
+namespace coxeter_triangulation {
+
+/** \class Linear_transformation
+ * \brief Transforms the zero-set of the function by a given linear transformation.
+ * The underlying function corresponds to f(M*x), where M is the transformation matrix.
+ *
+ * \tparam Function_ The function template parameter. Should be a model of
+ * the concept FunctionForImplicitManifold.
+ */
+template <class Function_>
+struct Linear_transformation {
+  /**
+   * \brief Value of the function at a specified point.
+   * @param[in] p The input point. The dimension needs to coincide with the ambient dimension.
+   */
+  Eigen::VectorXd operator()(const Eigen::VectorXd& p) const {
+    Eigen::VectorXd result = fun_(matrix_.householderQr().solve(p));
+    return result;
+  }
+
+  /** \brief Returns the domain (ambient) dimension. */
+  std::size_t amb_d() const { return fun_.amb_d(); }
+
+  /** \brief Returns the codomain dimension. */
+  std::size_t cod_d() const { return fun_.cod_d(); }
+
+  /** \brief Returns a point on the zero-set. */
+  Eigen::VectorXd seed() const {
+    Eigen::VectorXd result = fun_.seed();
+    result = matrix_ * result;
+    return result;
+  }
+
+  /**
+   * \brief Constructor of a linearly transformed function.
+   *
+   * @param[in] function The function to be linearly transformed.
+   * @param[in] matrix The transformation matrix. Its dimension should be d*d,
+   * where d is the domain (ambient) dimension of 'function'.
+   */
+  Linear_transformation(const Function_& function, const Eigen::MatrixXd& matrix) : fun_(function), matrix_(matrix) {}
+
+ private:
+  Function_ fun_;
+  Eigen::MatrixXd matrix_;
+};
+
+/**
+ * \brief Static constructor of a linearly transformed function.
+ *
+ * @param[in] function The function to be linearly transformed.
+ * @param[in] matrix The transformation matrix. Its dimension should be d*d,
+ * where d is the domain (ambient) dimension of 'function'.
+ *
+ * \tparam Function_ The function template parameter. Should be a model of
+ * the concept FunctionForImplicitManifold.
+ *
+ * \ingroup coxeter_triangulation
+ */
+template <class Function_>
+Linear_transformation<Function_> make_linear_transformation(const Function_& function, const Eigen::MatrixXd& matrix) {
+  return Linear_transformation<Function_>(function, matrix);
+}
+
+}  // namespace coxeter_triangulation
+
+}  // namespace Gudhi
+
+#endif