+/* free a graph allocated by graph_new() */
+
+typedef void (*graph_axis_unit_change_callback)(struct graph *g, int power_of_ten);
+void graph_x_axis_unit_change_notify(struct graph *g, graph_axis_unit_change_callback f);
+void graph_y_axis_unit_change_notify(struct graph *g, graph_axis_unit_change_callback f);
+/* The labels used on the x and y axes may be shortened. You can register for callbacks
+ * so that you can know how the labels are shorted, typically used to adjust the axis
+ * titles to display the proper units. The power_of_ten parameter indicates what power
+ * of ten the labels have been divided by (9, 6, 3, or 0, corresponding to billions,
+ * millions, thousands and ones.
+ */
+
+void graph_add_extra_space(struct graph *g, double left_percent, double right_percent,
+ double top_percent, double bottom_percent);
+/* graph_add_extra_space() adds extra space to edges of the the graph
+ * so that the data doesn't go to the very edges.
+ */
+
+extern int graph_has_tooltips(struct graph *g);
+extern const char *graph_find_tooltip(struct graph *g, int x, int y);
+extern int graph_contains_xy(struct graph *p, int x, int y);
+
+extern void graph_set_base_offset(struct graph *g, unsigned int base_offset);
+extern void graph_set_graph_all_zeroes(struct graph *g, unsigned int set);