Method grid_data_string

source/matplot/axes_objects/surface.cpp:351–474

    }

    std::string surface::grid_data_string() {
        std::stringstream ss;
        ss.precision(10);
        ss << std::fixed;
        const bool contour = (contour_base_ || contour_surface_);
        const bool palette_map_3d = palette_map_at_bottom_ ||
                                    palette_map_at_surface_ ||
                                    palette_map_at_top_;
        const bool repeat_data_for_contour_labels = contour && contour_text_;
        const bool manual_color = size(Z_data_) == size(C_data_);
        const size_t replicates = 1 + repeat_data_for_contour_labels;

        auto send_point = [](std::stringstream &ss, double x, double y,
                             double z, double c) {
            ss << "    " << x;
            ss << "  " << y;
            ss << "  " << z;
            if (std::isfinite(c)) {
                ss << "  " << c;
            }
            ss << "\n";
        };

        auto send_point_fill = [](std::stringstream &ss, double x, double y,
                                  double z, double zlow, double zhigh,
                                  double c) {
            ss << "    " << x;
            ss << "  " << y;
            ss << "  " << z;
            ss << "  " << zlow;
            ss << "  " << zhigh;
            if (std::isfinite(c)) {
                ss << "  " << c;
            }
            ss << "\n";
        };

        auto color_value = [&](size_t data_replicate, size_t i, size_t j) {
            if (manual_color && data_replicate == 0) {
                return C_data_[i][j];
            } else if (!palette_map_3d && !line_spec_.user_color()) {
                return Z_data_[i][j];
            } else {
                return NaN;
            }
        };

        for (size_t data_replicate = 0; data_replicate < replicates;
             ++data_replicate) {
            if (curtain_) {
                // open curtain - first line with zmin instead of z
                size_t i = Y_data_.size() - 1;
                send_point(ss, X_data_[i][0], Y_data_[i][0], zmin_,
                           color_value(data_replicate, i, 0));
                for (size_t j = 0; j < Y_data_[i].size(); ++j) {
                    send_point(ss, X_data_[i][j], Y_data_[i][j], zmin_,
                               color_value(data_replicate, i, j));
                }