graph: fix bar graph min/max displays

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/graph.c b/graph.c
index a0f1b056d696c6f979c9154c77e521812ea4c34a..3f2ee6aff2d6d35f5f505a0ef21c8c3bbb82969a 100644 (file)
--- a/graph.c
+++ b/graph.c
@@ -442,7 +442,14 @@ void bar_graph_draw(struct graph *bg, cairo_t *cr)
        nlabels = count_labels(bg->labels);
        space_per_label = (x2 - x1) / (double) nlabels;
 
        nlabels = count_labels(bg->labels);
        space_per_label = (x2 - x1) / (double) nlabels;
 

+       /*
+        * Start bars at 0 unless we have negative values, otherwise we
+        * present a skewed picture comparing label X and X+1.
+        */

        mindata = find_min_data(bg->labels);
        mindata = find_min_data(bg->labels);

+       if (mindata > 0)
+               mindata = 0;
+

        maxdata = find_max_data(bg->labels);
 
        if (fabs(maxdata - mindata) < 1e-20) {
        maxdata = find_max_data(bg->labels);
 
        if (fabs(maxdata - mindata) < 1e-20) {


@@ -452,8 +459,7 @@ void bar_graph_draw(struct graph *bg, cairo_t *cr)
                return;
        }
 
                return;
        }
 

-       graph_draw_y_ticks(bg, cr, x1, y1, x2, y2, mindata, maxdata, 10, 1);
-
+       maxdata = graph_draw_y_ticks(bg, cr, x1, y1, x2, y2, mindata, maxdata, 10, 1);

        i = 0;
        for (lb = bg->labels; lb; lb = lb->next) {
                int nvalues;
        i = 0;
        for (lb = bg->labels; lb; lb = lb->next) {
                int nvalues;