From 5ac24f9b8daaa0f41146a51fd5eeb0cea496a788 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Atgeirr=20Fl=C3=B8=20Rasmussen?= <atgeirr@sintef.no>
Date: Tue, 15 Jan 2013 13:44:18 +0100
Subject: [PATCH] Added addConstant() and multiplyGradient() methods.

So far only to class DGBasisBoundedTotalDegree.
---
 .../TransportModelTracerTofDiscGal.cpp        | 36 +++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/opm/core/transport/reorder/TransportModelTracerTofDiscGal.cpp b/opm/core/transport/reorder/TransportModelTracerTofDiscGal.cpp
index 19a64cb3a..44585673f 100644
--- a/opm/core/transport/reorder/TransportModelTracerTofDiscGal.cpp
+++ b/opm/core/transport/reorder/TransportModelTracerTofDiscGal.cpp
@@ -108,6 +108,42 @@ namespace Opm
                 }
             }
         }
+
+        /// Modify basis coefficients to add to the function value.
+        /// A function f = sum_i c_i b_i is assumed, and we change
+        /// it to (f + increment) by modifying the c_i. This is done without
+        /// modifying its gradient.
+        /// \param[in]  increment     Add this value to the function.
+        /// \param[in]  dim           Number of space dimensions.
+        /// \param[in]  degree        Polynomial degree of basis.
+        /// \param[out] coefficients  Coefficients {c_i} for a single cell.
+        static void addConstant(const double increment,
+                                const int /*dim*/,
+                                const int /*degree*/,
+                                double* coefficients)
+        {
+            coefficients[0] += increment;
+        }
+
+        /// Modify basis coefficients to change the function's slope.
+        /// A function f = sum_i c_i b_i is assumed, and we change
+        /// it to a function g with the property that grad g = factor * grad f
+        /// by modifying the c_i. This is done without modifying the average,
+        /// i.e. the integrals of g and f over the cell are the same.
+        /// \param[in]  factor        Multiply gradient by this factor.
+        /// \param[in]  dim           Number of space dimensions.
+        /// \param[in]  degree        Polynomial degree of basis.
+        /// \param[out] coefficients  Coefficients {c_i} for a single cell.
+        static void multiplyGradient(const double factor,
+                                     const int dim,
+                                     const int degree,
+                                     double* coefficients)
+        {
+            const int nb = numBasisFunc(dim, degree);
+            for (int ix = 1; ix < nb; ++ix) {
+                coefficients[ix] *= factor;
+            }
+        }
     };