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/*
* Copyright © 2006 Red Hat, Inc.
*
* Permission to use, copy, modify, distribute, and sell this software
* and its documentation for any purpose is hereby granted without
* fee, provided that the above copyright notice appear in all copies
* and that both that copyright notice and this permission notice
* appear in supporting documentation, and that the name of
* the authors not be used in advertising or publicity pertaining to
* distribution of the software without specific, written prior
* permission. The authors make no representations about the
* suitability of this software for any purpose. It is provided "as
* is" without express or implied warranty.
*
* THE AUTHORS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
* SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY SPECIAL,
* INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
* RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
* IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Authors: Carl Worth <cworth@cworth.org>
*/
#include "cairo-stats.h"
#include <assert.h>
void
_cairo_stats_compute (cairo_stats_t *stats,
cairo_time_t *values,
int num_values)
{
cairo_time_t sum, mean, q1, q3, iqr;
cairo_time_t outlier_min, outlier_max;
int i, min_valid, num_valid;
double s;
assert (num_values > 0);
if (num_values == 1) {
stats->min_ticks = stats->median_ticks = values[0];
stats->std_dev = 0;
stats->iterations = 1;
stats->values = values;
return;
}
/* First, identify any outliers, using the definition of "mild
* outliers" from:
*
* http://en.wikipedia.org/wiki/Outliers
*
* Which is that outliers are any values less than Q1 - 1.5 * IQR
* or greater than Q3 + 1.5 * IQR where Q1 and Q3 are the first
* and third quartiles and IQR is the inter-quartile range (Q3 -
* Q1).
*/
num_valid = num_values;
do {
num_values = num_valid;
qsort (values, num_values, sizeof (cairo_time_t), _cairo_time_cmp);
q1 = values[1*num_values/4];
q3 = values[3*num_values/4];
/* XXX assumes we have native uint64_t */
iqr = q3 - q1;
outlier_min = q1 - 3 * iqr / 2;
outlier_max = q3 + 3 * iqr / 2;
for (i = 0; i < num_values && values[i] < outlier_min; i++)
;
min_valid = i;
for (i = 0; i < num_values && values[i] <= outlier_max; i++)
;
num_valid = i - min_valid;
assert(num_valid);
values += min_valid;
} while (num_valid != num_values);
stats->values = values;
stats->iterations = num_valid;
stats->min_ticks = values[0];
stats->median_ticks = values[num_valid / 2];
sum = 0;
for (i = 0; i < num_valid; i++)
sum = _cairo_time_add (sum, values[i]);
mean = sum / num_valid;
/* Let's use a normalized std. deviation for easier comparison. */
s = 0;
for (i = 0; i < num_valid; i++) {
double delta = (values[i] - mean) / (double)mean;
s += delta * delta;
}
stats->std_dev = sqrt(s / num_valid);
}
cairo_bool_t
_cairo_histogram_init (cairo_histogram_t *h,
int width, int height)
{
h->width = width;
h->height = height;
if (h->width < 2 || h->height < 1)
return FALSE;
h->num_columns = width - 2;
h->num_rows = height - 1;
h->columns = malloc (sizeof(int)*h->num_columns);
return h->columns != NULL;
}
cairo_bool_t
_cairo_histogram_compute (cairo_histogram_t *h,
const cairo_time_t *values,
int num_values)
{
cairo_time_t delta;
int i;
if (num_values == 0)
return FALSE;
h->min_value = values[0];
h->max_value = values[0];
for (i = 1; i < num_values; i++) {
if (values[i] < h->min_value)
h->min_value = values[i];
if (values[i] > h->max_value)
h->max_value = values[i];
}
delta = h->max_value - h->min_value;
if (delta == 0)
return FALSE;
memset(h->columns, 0, sizeof(int)*h->num_columns);
h->max_count = 0;
for (i = 0; i < num_values; i++) {
int count = h->columns[(values[i] - h->min_value) * (h->num_columns - 1) / delta]++;
if (count > h->max_count)
h->max_count = count;
}
return TRUE;
}
void
_cairo_histogram_printf (cairo_histogram_t *h,
FILE *file)
{
int x, y, num_rows;
num_rows = h->num_rows;
if (h->max_count < num_rows)
num_rows = h->max_count;
for (y = 0; y < num_rows; y++) {
int min_count = ((num_rows - y - 1) * h->max_count) / num_rows + h->max_count / (2*num_rows);
fprintf (file, "|");
for (x = 0; x < h->num_columns; x++)
fprintf (file, "%c", h->columns[x] > min_count ? 'x' : ' ');
fprintf (file, "|\n");
}
fprintf(file, ".");
for (x = 0; x < h->num_columns; x++)
fprintf (file, "-");
fprintf (file, ".\n");
}
void
_cairo_histogram_fini (cairo_histogram_t *h)
{
free(h->columns);
}