PostGIS  3.0.6dev-r@@SVN_REVISION@@

◆ RASTER_quantile()

Datum RASTER_quantile ( PG_FUNCTION_ARGS  )

Definition at line 1724 of file rtpg_statistics.c.

1725 {
1726  FuncCallContext *funcctx;
1727  TupleDesc tupdesc;
1728 
1729  int i;
1730  rt_quantile quant;
1731  rt_quantile quant2;
1732  int call_cntr;
1733  int max_calls;
1734 
1735  /* first call of function */
1736  if (SRF_IS_FIRSTCALL()) {
1737  MemoryContext oldcontext;
1738 
1739  rt_pgraster *pgraster = NULL;
1740  rt_raster raster = NULL;
1741  rt_band band = NULL;
1742  int32_t bandindex = 0;
1743  int num_bands = 0;
1744  bool exclude_nodata_value = TRUE;
1745  double sample = 0;
1746  double *quantiles = NULL;
1747  uint32_t quantiles_count = 0;
1748  double quantile = 0;
1749  rt_bandstats stats = NULL;
1750  uint32_t count;
1751 
1752  int j;
1753  int n;
1754 
1755  ArrayType *array;
1756  Oid etype;
1757  Datum *e;
1758  bool *nulls;
1759  int16 typlen;
1760  bool typbyval;
1761  char typalign;
1762 
1763  /* create a function context for cross-call persistence */
1764  funcctx = SRF_FIRSTCALL_INIT();
1765 
1766  /* switch to memory context appropriate for multiple function calls */
1767  oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
1768 
1769  /* pgraster is null, return nothing */
1770  if (PG_ARGISNULL(0)) {
1771  MemoryContextSwitchTo(oldcontext);
1772  SRF_RETURN_DONE(funcctx);
1773  }
1774  pgraster = (rt_pgraster *) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
1775 
1776  raster = rt_raster_deserialize(pgraster, FALSE);
1777  if (!raster) {
1778  PG_FREE_IF_COPY(pgraster, 0);
1779  MemoryContextSwitchTo(oldcontext);
1780  elog(ERROR, "RASTER_quantile: Cannot deserialize raster");
1781  SRF_RETURN_DONE(funcctx);
1782  }
1783 
1784  /* band index is 1-based */
1785  bandindex = PG_GETARG_INT32(1);
1786  num_bands = rt_raster_get_num_bands(raster);
1787  if (bandindex < 1 || bandindex > num_bands) {
1788  elog(NOTICE, "Invalid band index (must use 1-based). Returning NULL");
1789  rt_raster_destroy(raster);
1790  PG_FREE_IF_COPY(pgraster, 0);
1791  MemoryContextSwitchTo(oldcontext);
1792  SRF_RETURN_DONE(funcctx);
1793  }
1794 
1795  /* exclude_nodata_value flag */
1796  if (!PG_ARGISNULL(2))
1797  exclude_nodata_value = PG_GETARG_BOOL(2);
1798 
1799  /* sample % */
1800  if (!PG_ARGISNULL(3)) {
1801  sample = PG_GETARG_FLOAT8(3);
1802  if (sample < 0 || sample > 1) {
1803  elog(NOTICE, "Invalid sample percentage (must be between 0 and 1). Returning NULL");
1804  rt_raster_destroy(raster);
1805  PG_FREE_IF_COPY(pgraster, 0);
1806  MemoryContextSwitchTo(oldcontext);
1807  SRF_RETURN_DONE(funcctx);
1808  }
1809  else if (FLT_EQ(sample, 0.0))
1810  sample = 1;
1811  }
1812  else
1813  sample = 1;
1814 
1815  /* quantiles */
1816  if (!PG_ARGISNULL(4)) {
1817  array = PG_GETARG_ARRAYTYPE_P(4);
1818  etype = ARR_ELEMTYPE(array);
1819  get_typlenbyvalalign(etype, &typlen, &typbyval, &typalign);
1820 
1821  switch (etype) {
1822  case FLOAT4OID:
1823  case FLOAT8OID:
1824  break;
1825  default:
1826  rt_raster_destroy(raster);
1827  PG_FREE_IF_COPY(pgraster, 0);
1828  MemoryContextSwitchTo(oldcontext);
1829  elog(ERROR, "RASTER_quantile: Invalid data type for quantiles");
1830  SRF_RETURN_DONE(funcctx);
1831  break;
1832  }
1833 
1834  deconstruct_array(array, etype, typlen, typbyval, typalign, &e,
1835  &nulls, &n);
1836 
1837  quantiles = palloc(sizeof(double) * n);
1838  for (i = 0, j = 0; i < n; i++) {
1839  if (nulls[i]) continue;
1840 
1841  switch (etype) {
1842  case FLOAT4OID:
1843  quantile = (double) DatumGetFloat4(e[i]);
1844  break;
1845  case FLOAT8OID:
1846  quantile = (double) DatumGetFloat8(e[i]);
1847  break;
1848  }
1849 
1850  if (quantile < 0 || quantile > 1) {
1851  elog(NOTICE, "Invalid value for quantile (must be between 0 and 1). Returning NULL");
1852  pfree(quantiles);
1853  rt_raster_destroy(raster);
1854  PG_FREE_IF_COPY(pgraster, 0);
1855  MemoryContextSwitchTo(oldcontext);
1856  SRF_RETURN_DONE(funcctx);
1857  }
1858 
1859  quantiles[j] = quantile;
1860  POSTGIS_RT_DEBUGF(5, "quantiles[%d] = %f", j, quantiles[j]);
1861  j++;
1862  }
1863  quantiles_count = j;
1864 
1865  if (j < 1) {
1866  pfree(quantiles);
1867  quantiles = NULL;
1868  }
1869  }
1870 
1871  /* get band */
1872  band = rt_raster_get_band(raster, bandindex - 1);
1873  if (!band) {
1874  elog(NOTICE, "Cannot find band at index %d. Returning NULL", bandindex);
1875  rt_raster_destroy(raster);
1876  PG_FREE_IF_COPY(pgraster, 0);
1877  MemoryContextSwitchTo(oldcontext);
1878  SRF_RETURN_DONE(funcctx);
1879  }
1880 
1881  /* get stats */
1882  stats = rt_band_get_summary_stats(band, (int) exclude_nodata_value, sample, 1, NULL, NULL, NULL);
1883  rt_band_destroy(band);
1884  rt_raster_destroy(raster);
1885  PG_FREE_IF_COPY(pgraster, 0);
1886  if (NULL == stats || NULL == stats->values) {
1887  elog(NOTICE, "Cannot retrieve summary statistics for band at index %d", bandindex);
1888  MemoryContextSwitchTo(oldcontext);
1889  SRF_RETURN_DONE(funcctx);
1890  }
1891  else if (stats->count < 1) {
1892  elog(NOTICE, "Cannot compute quantiles for band at index %d as the band has no values", bandindex);
1893  MemoryContextSwitchTo(oldcontext);
1894  SRF_RETURN_DONE(funcctx);
1895  }
1896 
1897  /* get quantiles */
1898  quant = rt_band_get_quantiles(stats, quantiles, quantiles_count, &count);
1899  if (quantiles_count) pfree(quantiles);
1900  pfree(stats);
1901  if (NULL == quant || !count) {
1902  elog(NOTICE, "Cannot compute quantiles for band at index %d", bandindex);
1903  MemoryContextSwitchTo(oldcontext);
1904  SRF_RETURN_DONE(funcctx);
1905  }
1906 
1907  POSTGIS_RT_DEBUGF(3, "%d quantiles returned", count);
1908 
1909  /* Store needed information */
1910  funcctx->user_fctx = quant;
1911 
1912  /* total number of tuples to be returned */
1913  funcctx->max_calls = count;
1914 
1915  /* Build a tuple descriptor for our result type */
1916  if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE) {
1917  ereport(ERROR, (
1918  errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1919  errmsg(
1920  "function returning record called in context "
1921  "that cannot accept type record"
1922  )
1923  ));
1924  }
1925 
1926  BlessTupleDesc(tupdesc);
1927  funcctx->tuple_desc = tupdesc;
1928 
1929  MemoryContextSwitchTo(oldcontext);
1930  }
1931 
1932  /* stuff done on every call of the function */
1933  funcctx = SRF_PERCALL_SETUP();
1934 
1935  call_cntr = funcctx->call_cntr;
1936  max_calls = funcctx->max_calls;
1937  tupdesc = funcctx->tuple_desc;
1938  quant2 = funcctx->user_fctx;
1939 
1940  /* do when there is more left to send */
1941  if (call_cntr < max_calls) {
1942  Datum values[VALUES_LENGTH];
1943  bool nulls[VALUES_LENGTH];
1944  HeapTuple tuple;
1945  Datum result;
1946 
1947  POSTGIS_RT_DEBUGF(3, "Result %d", call_cntr);
1948 
1949  memset(nulls, FALSE, sizeof(bool) * VALUES_LENGTH);
1950 
1951  values[0] = Float8GetDatum(quant2[call_cntr].quantile);
1952  values[1] = Float8GetDatum(quant2[call_cntr].value);
1953 
1954  /* build a tuple */
1955  tuple = heap_form_tuple(tupdesc, values, nulls);
1956 
1957  /* make the tuple into a datum */
1958  result = HeapTupleGetDatum(tuple);
1959 
1960  SRF_RETURN_NEXT(funcctx, result);
1961  }
1962  /* do when there is no more left */
1963  else {
1964  pfree(quant2);
1965  SRF_RETURN_DONE(funcctx);
1966  }
1967 }
TRUE
#define TRUE
Definition: dbfopen.c:169
FALSE
#define FALSE
Definition: dbfopen.c:168
rt_raster_destroy
void rt_raster_destroy(rt_raster raster)
Release memory associated to a raster.
Definition: rt_raster.c:82
FLT_EQ
#define FLT_EQ(x, y)
Definition: librtcore.h:2235
rt_band_destroy
void rt_band_destroy(rt_band band)
Destroy a raster band.
Definition: rt_band.c:340
rt_raster_get_num_bands
uint16_t rt_raster_get_num_bands(rt_raster raster)
Definition: rt_raster.c:372
rt_band_get_quantiles
rt_quantile rt_band_get_quantiles(rt_bandstats stats, double *quantiles, int quantiles_count, uint32_t *rtn_count)
Compute the default set of or requested quantiles for a set of data the quantile formula used is same...
Definition: rt_statistics.c:672
rt_band_get_summary_stats
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)
Compute summary statistics for a band.
Definition: rt_statistics.c:110
rt_raster_deserialize
rt_raster rt_raster_deserialize(void *serialized, int header_only)
Return a raster from a serialized form.
Definition: rt_serialize.c:725
rt_raster_get_band
rt_band rt_raster_get_band(rt_raster raster, int bandNum)
Return Nth band, or NULL if unavailable.
Definition: rt_raster.c:381
genraster.value
int value
Definition: genraster.py:62
genraster.count
int count
Definition: genraster.py:57
ovdump.band
band
Definition: ovdump.py:58
rtrowdump.raster
raster
Be careful!! Zeros function's input parameter can be a (height x width) array, not (width x height): ...
Definition: rtrowdump.py:121
VALUES_LENGTH
#define VALUES_LENGTH
Definition: rtpg_statistics.c:2400
POSTGIS_RT_DEBUGF
#define POSTGIS_RT_DEBUGF(level, msg,...)
Definition: rtpostgis.h:65
rt_band_t
Definition: librtcore.h:2314
rt_bandstats_t::count
uint32_t count
Definition: librtcore.h:2361
rt_bandstats_t::values
double * values
Definition: librtcore.h:2369
rt_bandstats_t
Definition: librtcore.h:2359
rt_quantile_t
Definition: librtcore.h:2386
rt_raster_serialized_t
Struct definitions.
Definition: librtcore.h:2251
rt_raster_t
Definition: librtcore.h:2285

References ovdump::band, rt_bandstats_t::count, genraster::count, FALSE, FLT_EQ, POSTGIS_RT_DEBUGF, rtrowdump::raster, rt_band_destroy(), rt_band_get_quantiles(), rt_band_get_summary_stats(), rt_raster_deserialize(), rt_raster_destroy(), rt_raster_get_band(), rt_raster_get_num_bands(), TRUE, genraster::value, rt_bandstats_t::values, and VALUES_LENGTH.

Here is the call graph for this function: