| // Ceres Solver - A fast non-linear least squares minimizer | |
| // Copyright 2019 Google Inc. All rights reserved. | |
| // http://ceres-solver.org/ | |
| // | |
| // Redistribution and use in source and binary forms, with or without | |
| // modification, are permitted provided that the following conditions are met: | |
| // | |
| // * Redistributions of source code must retain the above copyright notice, | |
| // this list of conditions and the following disclaimer. | |
| // * Redistributions in binary form must reproduce the above copyright notice, | |
| // this list of conditions and the following disclaimer in the documentation | |
| // and/or other materials provided with the distribution. | |
| // * Neither the name of Google Inc. nor the names of its contributors may be | |
| // used to endorse or promote products derived from this software without | |
| // specific prior written permission. | |
| // | |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | |
| // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE | |
| // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
| // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
| // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
| // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | |
| // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
| // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
| // POSSIBILITY OF SUCH DAMAGE. | |
| // | |
| // Author: wjr@google.com (William Rucklidge) | |
| // | |
| // This file contains a cost function that can apply a transformation to | |
| // each residual value before they are square-summed. | |
| namespace ceres { | |
| // This class allows you to apply different conditioning to the residual | |
| // values of a wrapped cost function. An example where this is useful is | |
| // where you have an existing cost function that produces N values, but you | |
| // want the total cost to be something other than just the sum of these | |
| // squared values - maybe you want to apply a different scaling to some | |
| // values, to change their contribution to the cost. | |
| // | |
| // Usage: | |
| // | |
| // // my_cost_function produces N residuals | |
| // CostFunction* my_cost_function = ... | |
| // CHECK_EQ(N, my_cost_function->num_residuals()); | |
| // vector<CostFunction*> conditioners; | |
| // | |
| // // Make N 1x1 cost functions (1 parameter, 1 residual) | |
| // CostFunction* f_1 = ... | |
| // conditioners.push_back(f_1); | |
| // ... | |
| // CostFunction* f_N = ... | |
| // conditioners.push_back(f_N); | |
| // ConditionedCostFunction* ccf = | |
| // new ConditionedCostFunction(my_cost_function, conditioners); | |
| // | |
| // Now ccf's residual i (i=0..N-1) will be passed though the i'th conditioner. | |
| // | |
| // ccf_residual[i] = f_i(my_cost_function_residual[i]) | |
| // | |
| // and the Jacobian will be affected appropriately. | |
| class CERES_EXPORT ConditionedCostFunction final : public CostFunction { | |
| public: | |
| // Builds a cost function based on a wrapped cost function, and a | |
| // per-residual conditioner. Takes ownership of all of the wrapped cost | |
| // functions, or not, depending on the ownership parameter. Conditioners | |
| // may be nullptr, in which case the corresponding residual is not modified. | |
| // | |
| // The conditioners can repeat. | |
| ConditionedCostFunction(CostFunction* wrapped_cost_function, | |
| const std::vector<CostFunction*>& conditioners, | |
| Ownership ownership); | |
| ~ConditionedCostFunction() override; | |
| bool Evaluate(double const* const* parameters, | |
| double* residuals, | |
| double** jacobians) const override; | |
| private: | |
| std::unique_ptr<CostFunction> wrapped_cost_function_; | |
| std::vector<CostFunction*> conditioners_; | |
| Ownership ownership_; | |
| }; | |
| } // namespace ceres | |