7 struct graph *graph_new(unsigned int xdim, unsigned int ydim, const char *font);
8 /* graph_new() Returns a new graph structure of the given dimensions and font */
9 void graph_set_size(struct graph *g, unsigned int xdim, unsigned int ydim);
10 /* graph_set_size() Changes the size of a graph to the given dimensions. */
11 void graph_set_position(struct graph *g, double xoffset, double yoffset);
12 /* graph_set_position() sets the x- and y-offset to translate the graph */
13 void bar_graph_draw(struct graph *g, cairo_t *cr);
14 /* bar_graph_draw() draws the given graph as a bar graph */
15 void line_graph_draw(struct graph *g, cairo_t *cr);
16 /* line_graph_draw draws the given graph as a line graph */
17 void line_graph_set_data_count_limit(struct graph *g, int per_label_limit);
18 /* line_graph_set_data_count_limit() limits the amount of data which can
19 * be added to a line graph. Once the limit is reached, the oldest data
20 * is discarded as new data is added
22 void graph_title(struct graph *g, const char *title);
23 /* graph_title() sets the main title of the graph to the given string */
24 void graph_x_title(struct graph *g, const char *title);
25 /* graph_x_title() sets the title of the x axis to the given string */
26 void graph_y_title(struct graph *g, const char *title);
27 /* graph_y_title() sets the title of the y axis to the given string */
28 void graph_add_label(struct graph *g, const char *label);
29 /* graph_add_label() adds a new "stream" of data to be graphed.
30 * For line charts, each label is a separate line on the graph.
31 * For bar charts, each label is a grouping of columns on the x-axis
37 * | *x **** | ** ** **
38 * | xxxx* ***** | ** xx ** xx **
39 * | x ** | ** xx ** xx ** xx
40 * | x | ** xx ** xx ** xx
41 * ----------------------- -------------------------
44 * For a line graph, the 'x's For a bar graph,
45 * would be on one "label", and 'A', 'B', and 'C'
46 * the '*'s would be on another are the labels.
50 int graph_add_data(struct graph *g, const char *label, const double value);
51 /* graph_add_data() is used to add data to the labels of a bar graph */
52 int graph_add_xy_data(struct graph *g, const char *label,
53 const double x, const double y);
54 /* graph_add_xy_data is used to add data to the labels of a line graph */
56 void graph_set_color(struct graph *g, const char *label,
57 double red, double green, double blue);
58 #define INVISIBLE_COLOR (-1.0)
59 /* graph_set_color is used to set the color used to plot the data in
60 * a line graph. INVISIBLE_COLOR can be used to plot the data invisibly.
61 * Invisible data will have the same effect on the scaling of the axes
65 void graph_free(struct graph *bg);
66 /* free a graph allocated by graph_new() */
68 typedef void (*graph_axis_unit_change_callback)(struct graph *g, int power_of_ten);
69 void graph_x_axis_unit_change_notify(struct graph *g, graph_axis_unit_change_callback f);
70 void graph_y_axis_unit_change_notify(struct graph *g, graph_axis_unit_change_callback f);
71 /* The labels used on the x and y axes may be shortened. You can register for callbacks
72 * so that you can know how the labels are shorted, typically used to adjust the axis
73 * titles to display the proper units. The power_of_ten parameter indicates what power
74 * of ten the labels have been divided by (9, 6, 3, or 0, corresponding to billions,
75 * millions, thousands and ones.
78 void graph_add_extra_space(struct graph *g, double left_percent, double right_percent,
79 double top_percent, double bottom_percent);
80 /* graph_add_extra_space() adds extra space to edges of the the graph
81 * so that the data doesn't go to the very edges.