Method transform

CvPlot/examples/examples_core.cpp:314–316

TEST_CASE("custom_transformation") {
    struct MyPolarTransformation : public Transformation {
        cv::Point2d transform(const cv::Point2d &p)const override {
            return{ std::cos(p.x)*p.y,std::sin(p.x)*p.y };
        }
        cv::Point2d untransform(const cv::Point2d &p)const override {
            return{ std::atan2(p.y, p.x), std::sqrt(p.x *p.x + p.y*p.y) };
        }