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/*
*
* WKTRaster - Raster Types for PostGIS
* http://trac.osgeo.org/postgis/wiki/WKTRaster
*
* Copyright (C) 2011-2013 Regents of the University of California
* <bkpark@ucdavis.edu>
* Copyright (C) 2010-2011 Jorge Arevalo <jorge.arevalo@deimos-space.com>
* Copyright (C) 2010-2011 David Zwarg <dzwarg@azavea.com>
* Copyright (C) 2009-2011 Pierre Racine <pierre.racine@sbf.ulaval.ca>
* Copyright (C) 2009-2011 Mateusz Loskot <mateusz@loskot.net>
* Copyright (C) 2008-2009 Sandro Santilli <strk@kbt.io>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include "librtcore.h"
#include "librtcore_internal.h"
/******************************************************************************
* quicksort
******************************************************************************/
#define SWAP(x, y) { double t; t = x; x = y; y = t; }
#define ORDER(x, y) if (x > y) SWAP(x, y)
static double pivot(double *left, double *right) {
double l, m, r, *p;
l = *left;
m = *(left + (right - left) / 2);
r = *right;
/* order */
ORDER(l, m);
ORDER(l, r);
ORDER(m, r);
/* pivot is higher of two values */
if (l < m) return m;
if (m < r) return r;
/* find pivot that isn't left */
for (p = left + 1; p <= right; ++p) {
if (*p != *left)
return (*p < *left) ? *left : *p;
}
/* all values are same */
return -1;
}
static double *partition(double *left, double *right, double pivot) {
while (left <= right) {
while (*left < pivot) ++left;
while (*right >= pivot) --right;
if (left < right) {
SWAP(*left, *right);
++left;
--right;
}
}
return left;
}
static void quicksort(double *left, double *right) {
double p = pivot(left, right);
double *pos;
if (p != -1) {
pos = partition(left, right, p);
quicksort(left, pos - 1);
quicksort(pos, right);
}
}
/******************************************************************************
* rt_band_get_summary_stats()
******************************************************************************/
/**
* Compute summary statistics for a band
*
* @param band : the band to query for summary stats
* @param exclude_nodata_value : if non-zero, ignore nodata values
* @param sample : percentage of pixels to sample
* @param inc_vals : flag to include values in return struct
* @param cK : number of pixels counted thus far in coverage
* @param cM : M component of 1-pass stddev for coverage
* @param cQ : Q component of 1-pass stddev for coverage
*
* @return the summary statistics for a band or NULL
*/
rt_bandstats
rt_band_get_summary_stats(
rt_band band,
int exclude_nodata_value, double sample, int inc_vals,
uint64_t *cK, double *cM, double *cQ
) {
uint32_t x = 0;
int64_t y = 0;
uint32_t z = 0;
uint32_t offset = 0;
uint32_t diff = 0;
int rtn;
int hasnodata = FALSE;
double nodata = 0;
double *values = NULL;
double value;
int isnodata = 0;
rt_bandstats stats = NULL;
uint32_t do_sample = 0;
uint32_t sample_size = 0;
uint32_t sample_per = 0;
uint32_t sample_int = 0;
uint32_t i = 0;
uint32_t j = 0;
double sum = 0;
uint32_t k = 0;
double M = 0;
double Q = 0;
#if POSTGIS_DEBUG_LEVEL > 0
clock_t start, stop;
double elapsed = 0;
#endif
RASTER_DEBUG(3, "starting");
#if POSTGIS_DEBUG_LEVEL > 0
start = clock();
#endif
assert(NULL != band);
/* band is empty (width < 1 || height < 1) */
if (band->width < 1 || band->height < 1) {
stats = (rt_bandstats) rtalloc(sizeof(struct rt_bandstats_t));
if (NULL == stats) {
rterror("rt_band_get_summary_stats: Could not allocate memory for stats");
return NULL;
}
rtwarn("Band is empty as width and/or height is 0");
stats->sample = 1;
stats->sorted = 0;
stats->values = NULL;
stats->count = 0;
stats->min = stats->max = 0;
stats->sum = 0;
stats->mean = 0;
stats->stddev = -1;
return stats;
}
hasnodata = rt_band_get_hasnodata_flag(band);
if (hasnodata != FALSE)
rt_band_get_nodata(band, &nodata);
else
exclude_nodata_value = 0;
RASTER_DEBUGF(3, "nodata = %f", nodata);
RASTER_DEBUGF(3, "hasnodata = %d", hasnodata);
RASTER_DEBUGF(3, "exclude_nodata_value = %d", exclude_nodata_value);
/* entire band is nodata */
if (rt_band_get_isnodata_flag(band) != FALSE) {
stats = (rt_bandstats) rtalloc(sizeof(struct rt_bandstats_t));
if (NULL == stats) {
rterror("rt_band_get_summary_stats: Could not allocate memory for stats");
return NULL;
}
stats->sample = 1;
stats->sorted = 0;
stats->values = NULL;
if (exclude_nodata_value) {
rtwarn("All pixels of band have the NODATA value");
stats->count = 0;
stats->min = stats->max = 0;
stats->sum = 0;
stats->mean = 0;
stats->stddev = -1;
}
else {
stats->count = band->width * band->height;
stats->min = stats->max = nodata;
stats->sum = stats->count * nodata;
stats->mean = nodata;
stats->stddev = 0;
}
return stats;
}
/* clamp percentage */
if (
(sample < 0 || FLT_EQ(sample, 0.0)) ||
(sample > 1 || FLT_EQ(sample, 1.0))
) {
do_sample = 0;
sample = 1;
}
else
do_sample = 1;
RASTER_DEBUGF(3, "do_sample = %d", do_sample);
/* sample all pixels */
if (!do_sample) {
sample_size = band->width * band->height;
sample_per = band->height;
}
/*
randomly sample a percentage of available pixels
sampling method is known as
"systematic random sample without replacement"
*/
else {
sample_size = round((band->width * band->height) * sample);
sample_per = round(sample_size / band->width);
if (sample_per < 1)
sample_per = 1;
sample_int = round(band->height / sample_per);
srand(time(NULL));
}
RASTER_DEBUGF(3, "sampling %d of %d available pixels w/ %d per set"
, sample_size, (band->width * band->height), sample_per);
if (inc_vals) {
values = rtalloc(sizeof(double) * sample_size);
if (NULL == values) {
rtwarn("Could not allocate memory for values");
inc_vals = 0;
}
}
/* initialize stats */
stats = (rt_bandstats) rtalloc(sizeof(struct rt_bandstats_t));
if (NULL == stats) {
rterror("rt_band_get_summary_stats: Could not allocate memory for stats");
return NULL;
}
stats->sample = sample;
stats->count = 0;
stats->sum = 0;
stats->mean = 0;
stats->stddev = -1;
stats->min = stats->max = 0;
stats->values = NULL;
stats->sorted = 0;
for (x = 0, j = 0, k = 0; x < band->width; x++) {
y = -1;
diff = 0;
for (i = 0, z = 0; i < sample_per; i++) {
if (!do_sample)
y = i;
else {
offset = (rand() % sample_int) + 1;
y += diff + offset;
diff = sample_int - offset;
}
RASTER_DEBUGF(5, "(x, y, z) = (%d, %d, %d)", x, y, z);
if (y >= band->height || z > sample_per) break;
rtn = rt_band_get_pixel(band, x, y, &value, &isnodata);
j++;
if (rtn == ES_NONE && (!exclude_nodata_value || (exclude_nodata_value && !isnodata))) {
/* inc_vals set, collect pixel values */
if (inc_vals) values[k] = value;
/* average */
k++;
sum += value;
/*
one-pass standard deviation
http://www.eecs.berkeley.edu/~mhoemmen/cs194/Tutorials/variance.pdf
*/
if (k == 1) {
Q = 0;
M = value;
}
else {
Q += (((k - 1) * pow(value - M, 2)) / k);
M += ((value - M ) / k);
}
/* coverage one-pass standard deviation */
if (NULL != cK) {
(*cK)++;
if (*cK == 1) {
*cQ = 0;
*cM = value;
}
else {
*cQ += (((*cK - 1) * pow(value - *cM, 2)) / *cK);
*cM += ((value - *cM ) / *cK);
}
}
/* min/max */
if (stats->count < 1) {
stats->count = 1;
stats->min = stats->max = value;
}
else {
if (value < stats->min)
stats->min = value;
if (value > stats->max)
stats->max = value;
}
}
z++;
}
}
RASTER_DEBUG(3, "sampling complete");
stats->count = k;
if (k > 0) {
if (inc_vals) {
/* free unused memory */
if (sample_size != k) {
values = rtrealloc(values, k * sizeof(double));
}
stats->values = values;
}
stats->sum = sum;
stats->mean = sum / k;
/* standard deviation */
if (!do_sample)
stats->stddev = sqrt(Q / k);
/* sample deviation */
else {
if (k < 2)
stats->stddev = -1;
else
stats->stddev = sqrt(Q / (k - 1));
}
}
/* inc_vals thus values allocated but not used */
else if (inc_vals)
rtdealloc(values);
/* if do_sample is one */
if (do_sample && k < 1)
rtwarn("All sampled pixels of band have the NODATA value");
#if POSTGIS_DEBUG_LEVEL > 0
stop = clock();
elapsed = ((double) (stop - start)) / CLOCKS_PER_SEC;
RASTER_DEBUGF(3, "(time, count, mean, stddev, min, max) = (%0.4f, %d, %f, %f, %f, %f)",
elapsed, stats->count, stats->mean, stats->stddev, stats->min, stats->max);
#endif
RASTER_DEBUG(3, "done");
return stats;
}
/******************************************************************************
* rt_band_get_histogram()
******************************************************************************/
/**
* Count the distribution of data
*
* @param stats : a populated stats struct for processing
* @param bin_count : the number of bins to group the data by
* @param bin_width : the width of each bin as an array
* @param bin_width_count : number of values in bin_width
* @param right : evaluate bins by (a,b] rather than default [a,b)
* @param min : user-defined minimum value of the histogram
* a value less than the minimum value is not counted in any bins
* if min = max, min and max are not used
* @param max : user-defined maximum value of the histogram
* a value greater than the max value is not counted in any bins
* if min = max, min and max are not used
* @param rtn_count : set to the number of bins being returned
*
* @return the histogram of the data or NULL
*/
rt_histogram
rt_band_get_histogram(
rt_bandstats stats,
uint32_t bin_count, double *bin_width, uint32_t bin_width_count,
int right, double min, double max,
uint32_t *rtn_count
) {
rt_histogram bins = NULL;
int init_width = 0;
uint32_t i;
uint32_t j;
double tmp;
double value;
int sum = 0;
double qmin;
double qmax;
#if POSTGIS_DEBUG_LEVEL > 0
clock_t start, stop;
double elapsed = 0;
#endif
RASTER_DEBUG(3, "starting");
#if POSTGIS_DEBUG_LEVEL > 0
start = clock();
#endif
assert(NULL != stats);
assert(NULL != rtn_count);
if (stats->count < 1 || NULL == stats->values) {
rterror("rt_util_get_histogram: rt_bandstats object has no value");
return NULL;
}
/* bin width must be positive numbers and not zero */
if (NULL != bin_width && bin_width_count > 0) {
for (i = 0; i < bin_width_count; i++) {
if (bin_width[i] < 0 || FLT_EQ(bin_width[i], 0.0)) {
rterror("rt_util_get_histogram: bin_width element is less than or equal to zero");
return NULL;
}
}
}
/* ignore min and max parameters */
if (FLT_EQ(max, min)) {
qmin = stats->min;
qmax = stats->max;
}
else {
qmin = min;
qmax = max;
if (qmin > qmax) {
qmin = max;
qmax = min;
}
}
/* # of bins not provided */
if (bin_count <= 0) {
/*
determine # of bins
http://en.wikipedia.org/wiki/Histogram
all computed bins are assumed to have equal width
*/
/* Square-root choice for stats->count < 30 */
if (stats->count < 30)
bin_count = ceil(sqrt(stats->count));
/* Sturges' formula for stats->count >= 30 */
else
bin_count = ceil(log2((double) stats->count) + 1.);
/* bin_width_count provided and bin_width has value */
if (bin_width_count > 0 && NULL != bin_width) {
/* user has defined something specific */
if (bin_width_count > bin_count)
bin_count = bin_width_count;
else if (bin_width_count > 1) {
tmp = 0;
for (i = 0; i < bin_width_count; i++) tmp += bin_width[i];
bin_count = ceil((qmax - qmin) / tmp) * bin_width_count;
}
else
bin_count = ceil((qmax - qmin) / bin_width[0]);
}
/* set bin width count to zero so that one can be calculated */
else {
bin_width_count = 0;
}
}
/* min and max the same */
if (FLT_EQ(qmax, qmin)) bin_count = 1;
RASTER_DEBUGF(3, "bin_count = %d", bin_count);
/* bin count = 1, all values are in one bin */
if (bin_count < 2) {
bins = rtalloc(sizeof(struct rt_histogram_t));
if (NULL == bins) {
rterror("rt_util_get_histogram: Could not allocate memory for histogram");
return NULL;
}
bins->count = stats->count;
bins->percent = -1;
bins->min = qmin;
bins->max = qmax;
bins->inc_min = bins->inc_max = 1;
*rtn_count = bin_count;
return bins;
}
/* establish bin width */
if (bin_width_count == 0) {
bin_width_count = 1;
/* bin_width unallocated */
if (NULL == bin_width) {
bin_width = rtalloc(sizeof(double));
if (NULL == bin_width) {
rterror("rt_util_get_histogram: Could not allocate memory for bin widths");
return NULL;
}
init_width = 1;
}
bin_width[0] = (qmax - qmin) / bin_count;
}
/* initialize bins */
bins = rtalloc(bin_count * sizeof(struct rt_histogram_t));
if (NULL == bins) {
rterror("rt_util_get_histogram: Could not allocate memory for histogram");
if (init_width) rtdealloc(bin_width);
return NULL;
}
if (!right)
tmp = qmin;
else
tmp = qmax;
for (i = 0; i < bin_count;) {
for (j = 0; j < bin_width_count; j++) {
bins[i].count = 0;
bins->percent = -1;
if (!right) {
bins[i].min = tmp;
tmp += bin_width[j];
bins[i].max = tmp;
bins[i].inc_min = 1;
bins[i].inc_max = 0;
}
else {
bins[i].max = tmp;
tmp -= bin_width[j];
bins[i].min = tmp;
bins[i].inc_min = 0;
bins[i].inc_max = 1;
}
i++;
}
}
if (!right) {
bins[bin_count - 1].inc_max = 1;
/* align last bin to the max value */
if (bins[bin_count - 1].max < qmax)
bins[bin_count - 1].max = qmax;
}
else {
bins[bin_count - 1].inc_min = 1;
/* align first bin to the min value */
if (bins[bin_count - 1].min > qmin)
bins[bin_count - 1].min = qmin;
}
/* process the values */
for (i = 0; i < stats->count; i++) {
value = stats->values[i];
/* default, [a, b) */
if (!right) {
for (j = 0; j < bin_count; j++) {
if (
(!bins[j].inc_max && value < bins[j].max) || (
bins[j].inc_max && (
(value < bins[j].max) ||
FLT_EQ(value, bins[j].max)
)
)
) {
bins[j].count++;
sum++;
break;
}
}
}
/* (a, b] */
else {
for (j = 0; j < bin_count; j++) {
if (
(!bins[j].inc_min && value > bins[j].min) || (
bins[j].inc_min && (
(value > bins[j].min) ||
FLT_EQ(value, bins[j].min)
)
)
) {
bins[j].count++;
sum++;
break;
}
}
}
}
for (i = 0; i < bin_count; i++) {
bins[i].percent = ((double) bins[i].count) / sum;
}
#if POSTGIS_DEBUG_LEVEL > 0
stop = clock();
elapsed = ((double) (stop - start)) / CLOCKS_PER_SEC;
RASTER_DEBUGF(3, "elapsed time = %0.4f", elapsed);
for (j = 0; j < bin_count; j++) {
RASTER_DEBUGF(5, "(min, max, inc_min, inc_max, count, sum, percent) = (%f, %f, %d, %d, %d, %d, %f)",
bins[j].min, bins[j].max, bins[j].inc_min, bins[j].inc_max, bins[j].count, sum, bins[j].percent);
}
#endif
if (init_width) rtdealloc(bin_width);
*rtn_count = bin_count;
RASTER_DEBUG(3, "done");
return bins;
}
/******************************************************************************
* rt_band_get_quantiles()
******************************************************************************/
/**
* Compute the default set of or requested quantiles for a set of data
* the quantile formula used is same as Excel and R default method
*
* @param stats : a populated stats struct for processing
* @param quantiles : the quantiles to be computed
* @param quantiles_count : the number of quantiles to be computed
* @param rtn_count : set to the number of quantiles being returned
*
* @return the default set of or requested quantiles for a band or NULL
*/
rt_quantile
rt_band_get_quantiles(
rt_bandstats stats,
double *quantiles, int quantiles_count,
uint32_t *rtn_count
) {
rt_quantile rtn;
int init_quantiles = 0;
int i = 0;
double h;
int hl;
#if POSTGIS_DEBUG_LEVEL > 0
clock_t start, stop;
double elapsed = 0;
#endif
RASTER_DEBUG(3, "starting");
#if POSTGIS_DEBUG_LEVEL > 0
start = clock();
#endif
assert(NULL != stats);
assert(NULL != rtn_count);
if (stats->count < 1 || NULL == stats->values) {
rterror("rt_band_get_quantiles: rt_bandstats object has no value");
return NULL;
}
/* quantiles not provided */
if (NULL == quantiles) {
/* quantile count not specified, default to quartiles */
if (quantiles_count < 2)
quantiles_count = 5;
quantiles = rtalloc(sizeof(double) * quantiles_count);
init_quantiles = 1;
if (NULL == quantiles) {
rterror("rt_band_get_quantiles: Could not allocate memory for quantile input");
return NULL;
}
quantiles_count--;
for (i = 0; i <= quantiles_count; i++)
quantiles[i] = ((double) i) / quantiles_count;
quantiles_count++;
}
/* check quantiles */
for (i = 0; i < quantiles_count; i++) {
if (quantiles[i] < 0. || quantiles[i] > 1.) {
rterror("rt_band_get_quantiles: Quantile value not between 0 and 1");
if (init_quantiles) rtdealloc(quantiles);
return NULL;
}
}
quicksort(quantiles, quantiles + quantiles_count - 1);
/* initialize rt_quantile */
rtn = rtalloc(sizeof(struct rt_quantile_t) * quantiles_count);
if (NULL == rtn) {
rterror("rt_band_get_quantiles: Could not allocate memory for quantile output");
if (init_quantiles) rtdealloc(quantiles);
return NULL;
}
/* sort values */
if (!stats->sorted) {
quicksort(stats->values, stats->values + stats->count - 1);
stats->sorted = 1;
}
/*
make quantiles
formula is that used in R (method 7) and Excel from
http://en.wikipedia.org/wiki/Quantile
*/
for (i = 0; i < quantiles_count; i++) {
rtn[i].quantile = quantiles[i];
h = ((stats->count - 1.) * quantiles[i]) + 1.;
hl = floor(h);
/* h greater than hl, do full equation */
if (h > hl)
rtn[i].value = stats->values[hl - 1] + ((h - hl) * (stats->values[hl] - stats->values[hl - 1]));
/* shortcut as second part of equation is zero */
else
rtn[i].value = stats->values[hl - 1];
}
#if POSTGIS_DEBUG_LEVEL > 0
stop = clock();
elapsed = ((double) (stop - start)) / CLOCKS_PER_SEC;
RASTER_DEBUGF(3, "elapsed time = %0.4f", elapsed);
#endif
*rtn_count = quantiles_count;
if (init_quantiles) rtdealloc(quantiles);
RASTER_DEBUG(3, "done");
return rtn;
}
/******************************************************************************
* rt_band_get_quantiles_stream()
******************************************************************************/
static struct quantile_llist_element *quantile_llist_search(
struct quantile_llist_element *element,
double needle
) {
if (NULL == element)
return NULL;
else if (FLT_NEQ(needle, element->value)) {
if (NULL != element->next)
return quantile_llist_search(element->next, needle);
else
return NULL;
}
else
return element;
}
static struct quantile_llist_element *quantile_llist_insert(
struct quantile_llist_element *element,
double value,
uint32_t *idx
) {
struct quantile_llist_element *qle = NULL;
if (NULL == element) {
qle = rtalloc(sizeof(struct quantile_llist_element));
RASTER_DEBUGF(4, "qle @ %p is only element in list", qle);
if (NULL == qle) return NULL;
qle->value = value;
qle->count = 1;
qle->prev = NULL;
qle->next = NULL;
if (NULL != idx) *idx = 0;
return qle;
}
else if (value > element->value) {
if (NULL != idx) *idx += 1;
if (NULL != element->next)
return quantile_llist_insert(element->next, value, idx);
/* insert as last element in list */
else {
qle = rtalloc(sizeof(struct quantile_llist_element));
RASTER_DEBUGF(4, "insert qle @ %p as last element", qle);
if (NULL == qle) return NULL;
qle->value = value;
qle->count = 1;
qle->prev = element;
qle->next = NULL;
element->next = qle;
return qle;
}
}
/* insert before current element */
else {
qle = rtalloc(sizeof(struct quantile_llist_element));
RASTER_DEBUGF(4, "insert qle @ %p before current element", qle);
if (NULL == qle) return NULL;
qle->value = value;
qle->count = 1;
if (NULL != element->prev) element->prev->next = qle;
qle->next = element;
qle->prev = element->prev;
element->prev = qle;
return qle;
}
}
static int quantile_llist_delete(struct quantile_llist_element *element) {
if (NULL == element) return 0;
/* beginning of list */
if (NULL == element->prev && NULL != element->next) {
element->next->prev = NULL;
}
/* end of list */
else if (NULL != element->prev && NULL == element->next) {
element->prev->next = NULL;
}
/* within list */
else if (NULL != element->prev && NULL != element->next) {
element->prev->next = element->next;
element->next->prev = element->prev;
}
RASTER_DEBUGF(4, "qle @ %p destroyed", element);
rtdealloc(element);
return 1;
}
int quantile_llist_destroy(struct quantile_llist **list, uint32_t list_count) {
struct quantile_llist_element *element = NULL;
uint32_t i;
if (NULL == *list) return 0;
for (i = 0; i < list_count; i++) {
element = (*list)[i].head;
while (NULL != element->next) {
quantile_llist_delete(element->next);
}
quantile_llist_delete(element);
rtdealloc((*list)[i].index);
}
rtdealloc(*list);
return 1;
}
static void quantile_llist_index_update(struct quantile_llist *qll, struct quantile_llist_element *qle, uint32_t idx) {
uint32_t anchor = (uint32_t) floor(idx / 100);
if (qll->tail == qle) return;
if (
(anchor != 0) && (
NULL == qll->index[anchor].element ||
idx <= qll->index[anchor].index
)
) {
qll->index[anchor].index = idx;
qll->index[anchor].element = qle;
}
if (anchor != 0 && NULL == qll->index[0].element) {
qll->index[0].index = 0;
qll->index[0].element = qll->head;
}
}
static void quantile_llist_index_delete(struct quantile_llist *qll, struct quantile_llist_element *qle) {
uint32_t i = 0;
for (i = 0; i < qll->index_max; i++) {
if (
NULL == qll->index[i].element ||
(qll->index[i].element) != qle
) {
continue;
}
RASTER_DEBUGF(5, "deleting index: %d => %f", i, qle->value);
qll->index[i].index = UINT32_MAX;
qll->index[i].element = NULL;
}
}
static struct quantile_llist_element *quantile_llist_index_search(
struct quantile_llist *qll,
double value,
uint32_t *index
) {
uint32_t i = 0, j = 0;
RASTER_DEBUGF(5, "searching index for value %f", value);
for (i = 0; i < qll->index_max; i++) {
if (NULL == qll->index[i].element) {
if (i < 1) break;
continue;
}
if (value > (qll->index[i]).element->value) continue;
if (FLT_EQ(value, qll->index[i].element->value)) {
RASTER_DEBUGF(5, "using index value at %d = %f", i, qll->index[i].element->value);
*index = i * 100;
return qll->index[i].element;
}
else if (i > 0) {
for (j = 1; j < i; j++) {
if (NULL != qll->index[i - j].element) {
RASTER_DEBUGF(5, "using index value at %d = %f", i - j, qll->index[i - j].element->value);
*index = (i - j) * 100;
return qll->index[i - j].element;
}
}
}
}
*index = 0;
return qll->head;
}
static void quantile_llist_index_reset(struct quantile_llist *qll) {
uint32_t i = 0;
RASTER_DEBUG(5, "resetting index");
for (i = 0; i < qll->index_max; i++) {
qll->index[i].index = UINT32_MAX;
qll->index[i].element = NULL;
}
}
/**
* Compute the default set of or requested quantiles for a coverage
*
* This function is based upon the algorithm described in:
*
* A One-Pass Space-Efficient Algorithm for Finding Quantiles (1995)
* by Rakesh Agrawal, Arun Swami
* in Proc. 7th Intl. Conf. Management of Data (COMAD-95)
*
* http://www.almaden.ibm.com/cs/projects/iis/hdb/Publications/papers/comad95.pdf
*
* In the future, it may be worth exploring algorithms that don't
* require the size of the coverage
*
* @param band : the band to include in the quantile search
* @param exclude_nodata_value : if non-zero, ignore nodata values
* @param sample : percentage of pixels to sample
* @param cov_count : number of values in coverage
* @param qlls : set of quantile_llist structures
* @param qlls_count : the number of quantile_llist structures
* @param quantiles : the quantiles to be computed
* if bot qlls and quantiles provided, qlls is used
* @param quantiles_count : the number of quantiles to be computed
* @param rtn_count : the number of quantiles being returned
*
* @return the default set of or requested quantiles for a band or NULL
*/
rt_quantile
rt_band_get_quantiles_stream(
rt_band band,
int exclude_nodata_value, double sample,
uint64_t cov_count,
struct quantile_llist **qlls, uint32_t *qlls_count,
double *quantiles, uint32_t quantiles_count,
uint32_t *rtn_count
) {
rt_quantile rtn = NULL;
int init_quantiles = 0;
struct quantile_llist *qll = NULL;
struct quantile_llist_element *qle = NULL;
struct quantile_llist_element *qls = NULL;
const uint32_t MAX_VALUES = 750;
uint8_t *data = NULL;
double value;
int isnodata = 0;
uint32_t a = 0;
uint32_t i = 0;
uint32_t j = 0;
uint32_t k = 0;
uint32_t x = 0;
int64_t y = 0;
uint32_t z = 0;
uint32_t idx = 0;
uint32_t offset = 0;
uint32_t diff = 0;
uint8_t exists = 0;
uint32_t do_sample = 0;
uint32_t sample_size = 0;
uint32_t sample_per = 0;
uint32_t sample_int = 0;
int status;
RASTER_DEBUG(3, "starting");
assert(NULL != band);
assert(cov_count > 1);
assert(NULL != rtn_count);
RASTER_DEBUGF(3, "cov_count = %d", cov_count);
data = rt_band_get_data(band);
if (data == NULL) {
rterror("rt_band_get_summary_stats: Cannot get band data");
return NULL;
}
if (!rt_band_get_hasnodata_flag(band))
exclude_nodata_value = 0;
RASTER_DEBUGF(3, "exclude_nodata_value = %d", exclude_nodata_value);
/* quantile_llist not provided */
if (NULL == *qlls) {
/* quantiles not provided */
if (NULL == quantiles) {
/* quantile count not specified, default to quartiles */
if (quantiles_count < 2)
quantiles_count = 5;
quantiles = rtalloc(sizeof(double) * quantiles_count);
init_quantiles = 1;
if (NULL == quantiles) {
rterror("rt_band_get_quantiles_stream: Could not allocate memory for quantile input");
return NULL;
}
quantiles_count--;
for (i = 0; i <= quantiles_count; i++)
quantiles[i] = ((double) i) / quantiles_count;
quantiles_count++;
}
/* check quantiles */
for (i = 0; i < quantiles_count; i++) {
if (quantiles[i] < 0. || quantiles[i] > 1.) {
rterror("rt_band_get_quantiles_stream: Quantile value not between 0 and 1");
if (init_quantiles) rtdealloc(quantiles);
return NULL;
}
}
quicksort(quantiles, quantiles + quantiles_count - 1);
/* initialize linked-list set */
*qlls_count = quantiles_count * 2;
RASTER_DEBUGF(4, "qlls_count = %d", *qlls_count);
*qlls = rtalloc(sizeof(struct quantile_llist) * *qlls_count);
if (NULL == *qlls) {
rterror("rt_band_get_quantiles_stream: Could not allocate memory for quantile output");
if (init_quantiles) rtdealloc(quantiles);
return NULL;
}
j = (uint32_t) floor(MAX_VALUES / 100.) + 1;
for (i = 0; i < *qlls_count; i++) {
qll = &((*qlls)[i]);
qll->quantile = quantiles[(i * quantiles_count) / *qlls_count];
qll->count = 0;
qll->sum1 = 0;
qll->sum2 = 0;
qll->head = NULL;
qll->tail = NULL;
/* initialize index */
qll->index = rtalloc(sizeof(struct quantile_llist_index) * j);
if (NULL == qll->index) {
rterror("rt_band_get_quantiles_stream: Could not allocate memory for quantile output");
if (init_quantiles) rtdealloc(quantiles);
return NULL;
}
qll->index_max = j;
quantile_llist_index_reset(qll);
/* AL-GEQ */
if (!(i % 2)) {
qll->algeq = 1;
qll->tau = (uint64_t) ROUND(cov_count - (cov_count * qll->quantile), 0);
if (qll->tau < 1) qll->tau = 1;
}
/* AL-GT */
else {
qll->algeq = 0;
qll->tau = cov_count - (*qlls)[i - 1].tau + 1;
}
RASTER_DEBUGF(4, "qll init: (algeq, quantile, count, tau, sum1, sum2) = (%d, %f, %d, %d, %d, %d)",
qll->algeq, qll->quantile, qll->count, qll->tau, qll->sum1, qll->sum2);
RASTER_DEBUGF(4, "qll init: (head, tail) = (%p, %p)", qll->head, qll->tail);
}
if (init_quantiles) rtdealloc(quantiles);
}
/* clamp percentage */
if (
(sample < 0 || FLT_EQ(sample, 0.0)) ||
(sample > 1 || FLT_EQ(sample, 1.0))
) {
do_sample = 0;
sample = 1;
}
else
do_sample = 1;
RASTER_DEBUGF(3, "do_sample = %d", do_sample);
/* sample all pixels */
if (!do_sample) {
sample_size = band->width * band->height;
sample_per = band->height;
}
/*
randomly sample a percentage of available pixels
sampling method is known as
"systematic random sample without replacement"
*/
else {
sample_size = round((band->width * band->height) * sample);
sample_per = round(sample_size / band->width);
sample_int = round(band->height / sample_per);
srand(time(NULL));
}
RASTER_DEBUGF(3, "sampling %d of %d available pixels w/ %d per set"
, sample_size, (band->width * band->height), sample_per);
for (x = 0, j = 0, k = 0; x < band->width; x++) {
y = -1;
diff = 0;
/* exclude_nodata_value = TRUE and band is NODATA */
if (exclude_nodata_value && rt_band_get_isnodata_flag(band)) {
RASTER_DEBUG(3, "Skipping quantile calcuation as band is NODATA");
break;
}
for (i = 0, z = 0; i < sample_per; i++) {
if (do_sample != 1)
y = i;
else {
offset = (rand() % sample_int) + 1;
y += diff + offset;
diff = sample_int - offset;
}
RASTER_DEBUGF(5, "(x, y, z) = (%d, %d, %d)", x, y, z);
if (y >= band->height || z > sample_per) break;
status = rt_band_get_pixel(band, x, y, &value, &isnodata);
j++;
if (status == ES_NONE && (!exclude_nodata_value || (exclude_nodata_value && !isnodata))) {
/* process each quantile */
for (a = 0; a < *qlls_count; a++) {
qll = &((*qlls)[a]);
qls = NULL;
RASTER_DEBUGF(4, "%d of %d (%f)", a + 1, *qlls_count, qll->quantile);
RASTER_DEBUGF(5, "qll before: (algeq, quantile, count, tau, sum1, sum2) = (%d, %f, %d, %d, %d, %d)",
qll->algeq, qll->quantile, qll->count, qll->tau, qll->sum1, qll->sum2);
RASTER_DEBUGF(5, "qll before: (head, tail) = (%p, %p)", qll->head, qll->tail);
/* OPTIMIZATION: shortcuts for quantiles of zero or one */
if (FLT_EQ(qll->quantile, 0.)) {
if (NULL != qll->head) {
if (value < qll->head->value)
qll->head->value = value;
}
else {
qle = quantile_llist_insert(qll->head, value, NULL);
qll->head = qle;
qll->tail = qle;
qll->count = 1;
}
RASTER_DEBUGF(4, "quantile shortcut for %f\n\n", qll->quantile);
continue;
}
else if (FLT_EQ(qll->quantile, 1.)) {
if (NULL != qll->head) {
if (value > qll->head->value)
qll->head->value = value;
}
else {
qle = quantile_llist_insert(qll->head, value, NULL);
qll->head = qle;
qll->tail = qle;
qll->count = 1;
}
RASTER_DEBUGF(4, "quantile shortcut for %f\n\n", qll->quantile);
continue;
}
/* value exists in list */
/* OPTIMIZATION: check to see if value exceeds last value */
if (NULL != qll->tail && value > qll->tail->value)
qle = NULL;
/* OPTIMIZATION: check to see if value equals last value */
else if (NULL != qll->tail && FLT_EQ(value, qll->tail->value))
qle = qll->tail;
/* OPTIMIZATION: use index if possible */
else {
qls = quantile_llist_index_search(qll, value, &idx);
qle = quantile_llist_search(qls, value);
}
/* value found */
if (NULL != qle) {
RASTER_DEBUGF(4, "%f found in list", value);
RASTER_DEBUGF(5, "qle before: (value, count) = (%f, %d)", qle->value, qle->count);
qle->count++;
qll->sum1++;
if (qll->algeq)
qll->sum2 = qll->sum1 - qll->head->count;
else
qll->sum2 = qll->sum1 - qll->tail->count;
RASTER_DEBUGF(4, "qle after: (value, count) = (%f, %d)", qle->value, qle->count);
}
/* can still add element */
else if (qll->count < MAX_VALUES) {
RASTER_DEBUGF(4, "Adding %f to list", value);
/* insert */
/* OPTIMIZATION: check to see if value exceeds last value */
if (NULL != qll->tail && (value > qll->tail->value || FLT_EQ(value, qll->tail->value))) {
idx = qll->count;
qle = quantile_llist_insert(qll->tail, value, &idx);
}
/* OPTIMIZATION: use index if possible */
else
qle = quantile_llist_insert(qls, value, &idx);
if (NULL == qle) return NULL;
RASTER_DEBUGF(5, "value added at index: %d => %f", idx, value);
qll->count++;
qll->sum1++;
/* first element */
if (NULL == qle->prev)
qll->head = qle;
/* last element */
if (NULL == qle->next)
qll->tail = qle;
if (qll->algeq)
qll->sum2 = qll->sum1 - qll->head->count;
else
qll->sum2 = qll->sum1 - qll->tail->count;
/* index is only needed if there are at least 100 values */
quantile_llist_index_update(qll, qle, idx);
RASTER_DEBUGF(5, "qle, prev, next, head, tail = %p, %p, %p, %p, %p", qle, qle->prev, qle->next, qll->head, qll->tail);
}
/* AL-GEQ */
else if (qll->algeq) {
RASTER_DEBUGF(4, "value, head->value = %f, %f", value, qll->head->value);
if (value < qll->head->value) {
/* ignore value if test isn't true */
if (qll->sum1 >= qll->tau) {
RASTER_DEBUGF(4, "skipping %f", value);
}
else {
/* delete last element */
RASTER_DEBUGF(4, "deleting %f from list", qll->tail->value);
qle = qll->tail->prev;
RASTER_DEBUGF(5, "to-be tail is %f with count %d", qle->value, qle->count);
qle->count += qll->tail->count;
quantile_llist_index_delete(qll, qll->tail);
quantile_llist_delete(qll->tail);
qll->tail = qle;
qll->count--;
RASTER_DEBUGF(5, "tail is %f with count %d", qll->tail->value, qll->tail->count);
/* insert value */
RASTER_DEBUGF(4, "adding %f to list", value);
/* OPTIMIZATION: check to see if value exceeds last value */
if (NULL != qll->tail && (value > qll->tail->value || FLT_EQ(value, qll->tail->value))) {
idx = qll->count;
qle = quantile_llist_insert(qll->tail, value, &idx);
}
/* OPTIMIZATION: use index if possible */
else {
qls = quantile_llist_index_search(qll, value, &idx);
qle = quantile_llist_insert(qls, value, &idx);
}
if (NULL == qle) return NULL;
RASTER_DEBUGF(5, "value added at index: %d => %f", idx, value);
qll->count++;
qll->sum1++;
/* first element */
if (NULL == qle->prev)
qll->head = qle;
/* last element */
if (NULL == qle->next)
qll->tail = qle;
qll->sum2 = qll->sum1 - qll->head->count;
quantile_llist_index_update(qll, qle, idx);
RASTER_DEBUGF(5, "qle, head, tail = %p, %p, %p", qle, qll->head, qll->tail);
}
}
else {
qle = qll->tail;
while (NULL != qle) {
if (qle->value < value) {
qle->count++;
qll->sum1++;
qll->sum2 = qll->sum1 - qll->head->count;
RASTER_DEBUGF(4, "incremented count of %f by 1 to %d", qle->value, qle->count);
break;
}
qle = qle->prev;
}
}
}
/* AL-GT */
else {
RASTER_DEBUGF(4, "value, tail->value = %f, %f", value, qll->tail->value);
if (value > qll->tail->value) {
/* ignore value if test isn't true */
if (qll->sum1 >= qll->tau) {
RASTER_DEBUGF(4, "skipping %f", value);
}
else {
/* delete last element */
RASTER_DEBUGF(4, "deleting %f from list", qll->head->value);
qle = qll->head->next;
RASTER_DEBUGF(5, "to-be tail is %f with count %d", qle->value, qle->count);
qle->count += qll->head->count;
quantile_llist_index_delete(qll, qll->head);
quantile_llist_delete(qll->head);
qll->head = qle;
qll->count--;
quantile_llist_index_update(qll, NULL, 0);
RASTER_DEBUGF(5, "tail is %f with count %d", qll->head->value, qll->head->count);
/* insert value */
RASTER_DEBUGF(4, "adding %f to list", value);
/* OPTIMIZATION: check to see if value exceeds last value */
if (NULL != qll->tail && (value > qll->tail->value || FLT_EQ(value, qll->tail->value))) {
idx = qll->count;
qle = quantile_llist_insert(qll->tail, value, &idx);
}
/* OPTIMIZATION: use index if possible */
else {
qls = quantile_llist_index_search(qll, value, &idx);
qle = quantile_llist_insert(qls, value, &idx);
}
if (NULL == qle) return NULL;
RASTER_DEBUGF(5, "value added at index: %d => %f", idx, value);
qll->count++;
qll->sum1++;
/* first element */
if (NULL == qle->prev)
qll->head = qle;
/* last element */
if (NULL == qle->next)
qll->tail = qle;
qll->sum2 = qll->sum1 - qll->tail->count;
quantile_llist_index_update(qll, qle, idx);
RASTER_DEBUGF(5, "qle, head, tail = %p, %p, %p", qle, qll->head, qll->tail);
}
}
else {
qle = qll->head;
while (NULL != qle) {
if (qle->value > value) {
qle->count++;
qll->sum1++;
qll->sum2 = qll->sum1 - qll->tail->count;
RASTER_DEBUGF(4, "incremented count of %f by 1 to %d", qle->value, qle->count);
break;
}
qle = qle->next;
}
}
}
RASTER_DEBUGF(5, "sum2, tau = %d, %d", qll->sum2, qll->tau);
if (qll->sum2 >= qll->tau) {
/* AL-GEQ */
if (qll->algeq) {
RASTER_DEBUGF(4, "deleting first element %f from list", qll->head->value);
if (NULL != qll->head->next) {
qle = qll->head->next;
qll->sum1 -= qll->head->count;
qll->sum2 = qll->sum1 - qle->count;
quantile_llist_index_delete(qll, qll->head);
quantile_llist_delete(qll->head);
qll->head = qle;
qll->count--;
quantile_llist_index_update(qll, NULL, 0);
}
else {
quantile_llist_delete(qll->head);
qll->head = NULL;
qll->tail = NULL;
qll->sum1 = 0;
qll->sum2 = 0;
qll->count = 0;
quantile_llist_index_reset(qll);
}
}
/* AL-GT */
else {
RASTER_DEBUGF(4, "deleting first element %f from list", qll->tail->value);
if (NULL != qll->tail->prev) {
qle = qll->tail->prev;
qll->sum1 -= qll->tail->count;
qll->sum2 = qll->sum1 - qle->count;
quantile_llist_index_delete(qll, qll->tail);
quantile_llist_delete(qll->tail);
qll->tail = qle;
qll->count--;
}
else {
quantile_llist_delete(qll->tail);
qll->head = NULL;
qll->tail = NULL;
qll->sum1 = 0;
qll->sum2 = 0;
qll->count = 0;
quantile_llist_index_reset(qll);
}
}
}
RASTER_DEBUGF(5, "qll after: (algeq, quantile, count, tau, sum1, sum2) = (%d, %f, %d, %d, %d, %d)",
qll->algeq, qll->quantile, qll->count, qll->tau, qll->sum1, qll->sum2);
RASTER_DEBUGF(5, "qll after: (head, tail) = (%p, %p)\n\n", qll->head, qll->tail);
}
}
else {
RASTER_DEBUGF(5, "skipping value at (x, y) = (%d, %d)", x, y);
}
z++;
}
}
/* process quantiles */
*rtn_count = *qlls_count / 2;
rtn = rtalloc(sizeof(struct rt_quantile_t) * *rtn_count);
if (NULL == rtn) return NULL;
RASTER_DEBUGF(3, "returning %d quantiles", *rtn_count);
for (i = 0, k = 0; i < *qlls_count; i++) {
qll = &((*qlls)[i]);
exists = 0;
for (x = 0; x < k; x++) {
if (FLT_EQ(qll->quantile, rtn[x].quantile)) {
exists = 1;
break;
}
}
if (exists) continue;
RASTER_DEBUGF(5, "qll: (algeq, quantile, count, tau, sum1, sum2) = (%d, %f, %d, %d, %d, %d)",
qll->algeq, qll->quantile, qll->count, qll->tau, qll->sum1, qll->sum2);
RASTER_DEBUGF(5, "qll: (head, tail) = (%p, %p)", qll->head, qll->tail);
rtn[k].quantile = qll->quantile;
rtn[k].has_value = 0;
/* check that qll->head and qll->tail have value */
if (qll->head == NULL || qll->tail == NULL)
continue;
/* AL-GEQ */
if (qll->algeq)
qle = qll->head;
/* AM-GT */
else
qle = qll->tail;
exists = 0;
for (j = i + 1; j < *qlls_count; j++) {
if (FLT_EQ((*qlls)[j].quantile, qll->quantile)) {
RASTER_DEBUGF(5, "qlls[%d]: (algeq, quantile, count, tau, sum1, sum2) = (%d, %f, %d, %d, %d, %d)",
j, (*qlls)[j].algeq, (*qlls)[j].quantile, (*qlls)[j].count, (*qlls)[j].tau, (*qlls)[j].sum1, (*qlls)[j].sum2);
RASTER_DEBUGF(5, "qlls[%d]: (head, tail) = (%p, %p)", j, (*qlls)[j].head, (*qlls)[j].tail);
exists = 1;
break;
}
}
/* weighted average for quantile */
if (exists) {
if ((*qlls)[j].algeq) {
rtn[k].value = ((qle->value * qle->count) + ((*qlls)[j].head->value * (*qlls)[j].head->count)) / (qle->count + (*qlls)[j].head->count);
RASTER_DEBUGF(5, "qlls[%d].head: (value, count) = (%f, %d)", j, (*qlls)[j].head->value, (*qlls)[j].head->count);
}
else {
rtn[k].value = ((qle->value * qle->count) + ((*qlls)[j].tail->value * (*qlls)[j].tail->count)) / (qle->count + (*qlls)[j].tail->count);
RASTER_DEBUGF(5, "qlls[%d].tail: (value, count) = (%f, %d)", j, (*qlls)[j].tail->value, (*qlls)[j].tail->count);
}
}
/* straight value for quantile */
else {
rtn[k].value = qle->value;
}
rtn[k].has_value = 1;
RASTER_DEBUGF(3, "(quantile, value) = (%f, %f)\n\n", rtn[k].quantile, rtn[k].value);
k++;
}
RASTER_DEBUG(3, "done");
return rtn;
}
/******************************************************************************
* rt_band_get_value_count()
******************************************************************************/
/**
* Count the number of times provided value(s) occur in
* the band
*
* @param band : the band to query for minimum and maximum pixel values
* @param exclude_nodata_value : if non-zero, ignore nodata values
* @param search_values : array of values to count
* @param search_values_count : the number of search values
* @param roundto : the decimal place to round the values to
* @param rtn_total : the number of pixels examined in the band
* @param rtn_count : the number of value counts being returned
*
* @return the number of times the provide value(s) occur or NULL
*/
rt_valuecount
rt_band_get_value_count(
rt_band band, int exclude_nodata_value,
double *search_values, uint32_t search_values_count, double roundto,
uint32_t *rtn_total, uint32_t *rtn_count
) {
rt_valuecount vcnts = NULL;
rt_pixtype pixtype = PT_END;
uint8_t *data = NULL;
double nodata = 0;
int scale = 0;
int doround = 0;
double tmpd = 0;
uint32_t i = 0;
uint32_t x = 0;
uint32_t y = 0;
int rtn;
double pxlval;
int isnodata = 0;
double rpxlval;
uint32_t total = 0;
uint32_t vcnts_count = 0;
uint32_t new_valuecount = 0;
#if POSTGIS_DEBUG_LEVEL > 0
clock_t start, stop;
double elapsed = 0;
#endif
RASTER_DEBUG(3, "starting");
#if POSTGIS_DEBUG_LEVEL > 0
start = clock();
#endif
assert(NULL != band);
assert(NULL != rtn_count);
data = rt_band_get_data(band);
if (data == NULL) {
rterror("rt_band_get_summary_stats: Cannot get band data");
return NULL;
}
pixtype = band->pixtype;
if (rt_band_get_hasnodata_flag(band)) {
rt_band_get_nodata(band, &nodata);
RASTER_DEBUGF(3, "hasnodata, nodataval = 1, %f", nodata);
}
else {
exclude_nodata_value = 0;
RASTER_DEBUG(3, "hasnodata, nodataval = 0, 0");
}
RASTER_DEBUGF(3, "exclude_nodata_value = %d", exclude_nodata_value);
/* process roundto */
if (roundto < 0 || FLT_EQ(roundto, 0.0)) {
roundto = 0;
scale = 0;
}
/* tenths, hundredths, thousandths, etc */
else if (roundto < 1) {
switch (pixtype) {
/* integer band types don't have digits after the decimal place */
case PT_1BB:
case PT_2BUI:
case PT_4BUI:
case PT_8BSI:
case PT_8BUI:
case PT_16BSI:
case PT_16BUI:
case PT_32BSI:
case PT_32BUI:
roundto = 0;
break;
/* floating points, check the rounding */
case PT_32BF:
case PT_64BF:
for (scale = 0; scale <= 20; scale++) {
tmpd = roundto * pow(10, scale);
if (FLT_EQ((tmpd - ((int) tmpd)), 0.0)) break;
}
break;
case PT_END:
break;
}
}
/* ones, tens, hundreds, etc */
else {
for (scale = 0; scale >= -20; scale--) {
tmpd = roundto * pow(10, scale);
if (tmpd < 1 || FLT_EQ(tmpd, 1.0)) {
if (scale == 0) doround = 1;
break;
}
}
}
if (scale != 0 || doround)
doround = 1;
else
doround = 0;
RASTER_DEBUGF(3, "scale = %d", scale);
RASTER_DEBUGF(3, "doround = %d", doround);
/* process search_values */
if (search_values_count > 0 && NULL != search_values) {
vcnts = (rt_valuecount) rtalloc(sizeof(struct rt_valuecount_t) * search_values_count);
if (NULL == vcnts) {
rterror("rt_band_get_count_of_values: Could not allocate memory for value counts");
*rtn_count = 0;
return NULL;
}
for (i = 0; i < search_values_count; i++) {
vcnts[i].count = 0;
vcnts[i].percent = 0;
if (!doround)
vcnts[i].value = search_values[i];
else
vcnts[i].value = ROUND(search_values[i], scale);
}
vcnts_count = i;
}
else
search_values_count = 0;
RASTER_DEBUGF(3, "search_values_count = %d", search_values_count);
/* entire band is nodata */
if (rt_band_get_isnodata_flag(band) != FALSE) {
if (exclude_nodata_value) {
rtwarn("All pixels of band have the NODATA value");
return NULL;
}
else {
if (search_values_count > 0) {
/* check for nodata match */
for (i = 0; i < search_values_count; i++) {
if (!doround)
tmpd = nodata;
else
tmpd = ROUND(nodata, scale);
if (FLT_NEQ(tmpd, vcnts[i].value))
continue;
vcnts[i].count = band->width * band->height;
if (NULL != rtn_total) *rtn_total = vcnts[i].count;
vcnts->percent = 1.0;
}
*rtn_count = vcnts_count;
}
/* no defined search values */
else {
vcnts = (rt_valuecount) rtalloc(sizeof(struct rt_valuecount_t));
if (NULL == vcnts) {
rterror("rt_band_get_count_of_values: Could not allocate memory for value counts");
*rtn_count = 0;
return NULL;
}
vcnts->value = nodata;
vcnts->count = band->width * band->height;
if (NULL != rtn_total) *rtn_total = vcnts[i].count;
vcnts->percent = 1.0;
*rtn_count = 1;
}
return vcnts;
}
}
for (x = 0; x < band->width; x++) {
for (y = 0; y < band->height; y++) {
rtn = rt_band_get_pixel(band, x, y, &pxlval, &isnodata);
/* error getting value, continue */
if (rtn != ES_NONE)
continue;
if (!exclude_nodata_value || (exclude_nodata_value && !isnodata)) {
total++;
if (doround) {
rpxlval = ROUND(pxlval, scale);
}
else
rpxlval = pxlval;
RASTER_DEBUGF(5, "(pxlval, rpxlval) => (%0.6f, %0.6f)", pxlval, rpxlval);
new_valuecount = 1;
/* search for match in existing valuecounts */
for (i = 0; i < vcnts_count; i++) {
/* match found */
if (FLT_EQ(vcnts[i].value, rpxlval)) {
vcnts[i].count++;
new_valuecount = 0;
RASTER_DEBUGF(5, "(value, count) => (%0.6f, %d)", vcnts[i].value, vcnts[i].count);
break;
}
}
/*
don't add new valuecount either because
- no need for new one
- user-defined search values
*/
if (!new_valuecount || search_values_count > 0) continue;
/* add new valuecount */
vcnts = rtrealloc(vcnts, sizeof(struct rt_valuecount_t) * (vcnts_count + 1));
if (NULL == vcnts) {
rterror("rt_band_get_count_of_values: Could not allocate memory for value counts");
*rtn_count = 0;
return NULL;
}
vcnts[vcnts_count].value = rpxlval;
vcnts[vcnts_count].count = 1;
vcnts[vcnts_count].percent = 0;
RASTER_DEBUGF(5, "(value, count) => (%0.6f, %d)", vcnts[vcnts_count].value, vcnts[vcnts_count].count);
vcnts_count++;
}
}
}
#if POSTGIS_DEBUG_LEVEL > 0
stop = clock();
elapsed = ((double) (stop - start)) / CLOCKS_PER_SEC;
RASTER_DEBUGF(3, "elapsed time = %0.4f", elapsed);
#endif
for (i = 0; i < vcnts_count; i++) {
vcnts[i].percent = (double) vcnts[i].count / total;
RASTER_DEBUGF(5, "(value, count) => (%0.6f, %d)", vcnts[i].value, vcnts[i].count);
}
RASTER_DEBUG(3, "done");
if (NULL != rtn_total) *rtn_total = total;
*rtn_count = vcnts_count;
return vcnts;
}
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