Added a function to save coefficients as json file

CMakeLists.txt

@@ -93,6 +93,7 @@ set(HEADERS
 	include/eos/morphablemodel/PcaModel.hpp
 	include/eos/morphablemodel/MorphableModel.hpp
 	include/eos/morphablemodel/Blendshape.hpp
+	include/eos/morphablemodel/coefficients.hpp
 	include/eos/morphablemodel/io/cvssp.hpp
 	include/eos/morphablemodel/io/mat_cerealisation.hpp
 	include/eos/fitting/affine_camera_estimation.hpp

include/eos/morphablemodel/coefficients.hpp

+/*
+ * Eos - A 3D Morphable Model fitting library written in modern C++11/14.
+ *
+ * File: include/eos/morphablemodel/coefficients.hpp
+ *
+ * Copyright 2016 Patrik Huber
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#pragma once
+
+#ifndef COEFFICIENTS_HPP_
+#define COEFFICIENTS_HPP_
+
+#include "cereal/cereal.hpp"
+#include "cereal/archives/json.hpp"
+
+#include <vector>
+#include <string>
+
+namespace eos {
+	namespace morphablemodel {
+
+/**
+ * Saves coefficients (for example PCA shape coefficients) to a json file.
+ *
+ * @param[in] coefficients A vector of coefficients.
+ * @param[in] filename The file to write.
+ * @throws std::runtime_error if unable to open the given file for writing.
+ */
+void save_coefficients(std::vector<float> coefficients, std::string filename)
+{
+	std::ofstream file(filename);
+	if (file.fail()) {
+		throw std::runtime_error("Error opening file for writing: " + filename);
+	}
+	cereal::JSONOutputArchive output_archive(file);
+	output_archive(cereal::make_nvp("shape_coefficients", coefficients));
+};
+
+	} /* namespace morphablemodel */
+} /* namespace eos */
+
+#endif /* COEFFICIENTS_HPP_ */