PostGIS  2.4.9dev-r@@SVN_REVISION@@

◆ RASTER_histogram()

Datum RASTER_histogram ( PG_FUNCTION_ARGS  )

Definition at line 921 of file rtpg_statistics.c.

References ovdump::band, genraster::count, rt_bandstats_t::count, rtpg_summarystats_arg_t::exclude_nodata_value, FALSE, FLT_EQ, PG_FUNCTION_INFO_V1(), POSTGIS_RT_DEBUG, POSTGIS_RT_DEBUGF, rtrowdump::raster, RASTER_histogramCoverage(), rt_band_destroy(), rt_band_get_histogram(), rt_band_get_summary_stats(), rt_raster_deserialize(), rt_raster_destroy(), rt_raster_get_band(), rt_raster_get_num_bands(), rtpg_summarystats_arg_t::sample, rtpg_summarystats_arg_t::stats, TRUE, rt_bandstats_t::values, and VALUES_LENGTH.

Referenced by RASTER_summaryStats_finalfn().

922 {
923  FuncCallContext *funcctx;
924  TupleDesc tupdesc;
925 
926  int i;
927  rt_histogram hist;
928  rt_histogram hist2;
929  int call_cntr;
930  int max_calls;
931 
932  /* first call of function */
933  if (SRF_IS_FIRSTCALL()) {
934  MemoryContext oldcontext;
935 
936  rt_pgraster *pgraster = NULL;
937  rt_raster raster = NULL;
938  rt_band band = NULL;
939  int32_t bandindex = 1;
940  int num_bands = 0;
941  bool exclude_nodata_value = TRUE;
942  double sample = 0;
943  uint32_t bin_count = 0;
944  double *bin_width = NULL;
945  uint32_t bin_width_count = 0;
946  double width = 0;
947  bool right = FALSE;
948  double min = 0;
949  double max = 0;
950  rt_bandstats stats = NULL;
951  uint32_t count;
952 
953  int j;
954  int n;
955 
956  ArrayType *array;
957  Oid etype;
958  Datum *e;
959  bool *nulls;
960  int16 typlen;
961  bool typbyval;
962  char typalign;
963 
964  POSTGIS_RT_DEBUG(3, "RASTER_histogram: Starting");
965 
966  /* create a function context for cross-call persistence */
967  funcctx = SRF_FIRSTCALL_INIT();
968 
969  /* switch to memory context appropriate for multiple function calls */
970  oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
971 
972  /* pgraster is null, return nothing */
973  if (PG_ARGISNULL(0)) {
974  MemoryContextSwitchTo(oldcontext);
975  SRF_RETURN_DONE(funcctx);
976  }
977  pgraster = (rt_pgraster *) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
978 
979  raster = rt_raster_deserialize(pgraster, FALSE);
980  if (!raster) {
981  PG_FREE_IF_COPY(pgraster, 0);
982  MemoryContextSwitchTo(oldcontext);
983  elog(ERROR, "RASTER_histogram: Cannot deserialize raster");
984  SRF_RETURN_DONE(funcctx);
985  }
986 
987  /* band index is 1-based */
988  if (!PG_ARGISNULL(1))
989  bandindex = PG_GETARG_INT32(1);
990  num_bands = rt_raster_get_num_bands(raster);
991  if (bandindex < 1 || bandindex > num_bands) {
992  elog(NOTICE, "Invalid band index (must use 1-based). Returning NULL");
993  rt_raster_destroy(raster);
994  PG_FREE_IF_COPY(pgraster, 0);
995  MemoryContextSwitchTo(oldcontext);
996  SRF_RETURN_DONE(funcctx);
997  }
998 
999  /* exclude_nodata_value flag */
1000  if (!PG_ARGISNULL(2))
1001  exclude_nodata_value = PG_GETARG_BOOL(2);
1002 
1003  /* sample % */
1004  if (!PG_ARGISNULL(3)) {
1005  sample = PG_GETARG_FLOAT8(3);
1006  if (sample < 0 || sample > 1) {
1007  elog(NOTICE, "Invalid sample percentage (must be between 0 and 1). Returning NULL");
1008  rt_raster_destroy(raster);
1009  PG_FREE_IF_COPY(pgraster, 0);
1010  MemoryContextSwitchTo(oldcontext);
1011  SRF_RETURN_DONE(funcctx);
1012  }
1013  else if (FLT_EQ(sample, 0.0))
1014  sample = 1;
1015  }
1016  else
1017  sample = 1;
1018 
1019  /* bin_count */
1020  if (!PG_ARGISNULL(4)) {
1021  bin_count = PG_GETARG_INT32(4);
1022  if (bin_count < 1) bin_count = 0;
1023  }
1024 
1025  /* bin_width */
1026  if (!PG_ARGISNULL(5)) {
1027  array = PG_GETARG_ARRAYTYPE_P(5);
1028  etype = ARR_ELEMTYPE(array);
1029  get_typlenbyvalalign(etype, &typlen, &typbyval, &typalign);
1030 
1031  switch (etype) {
1032  case FLOAT4OID:
1033  case FLOAT8OID:
1034  break;
1035  default:
1036  rt_raster_destroy(raster);
1037  PG_FREE_IF_COPY(pgraster, 0);
1038  MemoryContextSwitchTo(oldcontext);
1039  elog(ERROR, "RASTER_histogram: Invalid data type for width");
1040  SRF_RETURN_DONE(funcctx);
1041  break;
1042  }
1043 
1044  deconstruct_array(array, etype, typlen, typbyval, typalign, &e,
1045  &nulls, &n);
1046 
1047  bin_width = palloc(sizeof(double) * n);
1048  for (i = 0, j = 0; i < n; i++) {
1049  if (nulls[i]) continue;
1050 
1051  switch (etype) {
1052  case FLOAT4OID:
1053  width = (double) DatumGetFloat4(e[i]);
1054  break;
1055  case FLOAT8OID:
1056  width = (double) DatumGetFloat8(e[i]);
1057  break;
1058  }
1059 
1060  if (width < 0 || FLT_EQ(width, 0.0)) {
1061  elog(NOTICE, "Invalid value for width (must be greater than 0). Returning NULL");
1062  pfree(bin_width);
1063  rt_raster_destroy(raster);
1064  PG_FREE_IF_COPY(pgraster, 0);
1065  MemoryContextSwitchTo(oldcontext);
1066  SRF_RETURN_DONE(funcctx);
1067  }
1068 
1069  bin_width[j] = width;
1070  POSTGIS_RT_DEBUGF(5, "bin_width[%d] = %f", j, bin_width[j]);
1071  j++;
1072  }
1073  bin_width_count = j;
1074 
1075  if (j < 1) {
1076  pfree(bin_width);
1077  bin_width = NULL;
1078  }
1079  }
1080 
1081  /* right */
1082  if (!PG_ARGISNULL(6))
1083  right = PG_GETARG_BOOL(6);
1084 
1085  /* min */
1086  if (!PG_ARGISNULL(7)) min = PG_GETARG_FLOAT8(7);
1087 
1088  /* max */
1089  if (!PG_ARGISNULL(8)) max = PG_GETARG_FLOAT8(8);
1090 
1091  /* get band */
1092  band = rt_raster_get_band(raster, bandindex - 1);
1093  if (!band) {
1094  elog(NOTICE, "Cannot find band at index %d. Returning NULL", bandindex);
1095  rt_raster_destroy(raster);
1096  PG_FREE_IF_COPY(pgraster, 0);
1097  MemoryContextSwitchTo(oldcontext);
1098  SRF_RETURN_DONE(funcctx);
1099  }
1100 
1101  /* get stats */
1102  stats = rt_band_get_summary_stats(band, (int) exclude_nodata_value, sample, 1, NULL, NULL, NULL);
1103  rt_band_destroy(band);
1104  rt_raster_destroy(raster);
1105  PG_FREE_IF_COPY(pgraster, 0);
1106  if (NULL == stats || NULL == stats->values) {
1107  elog(NOTICE, "Cannot compute summary statistics for band at index %d", bandindex);
1108  MemoryContextSwitchTo(oldcontext);
1109  SRF_RETURN_DONE(funcctx);
1110  }
1111  else if (stats->count < 1) {
1112  elog(NOTICE, "Cannot compute histogram for band at index %d as the band has no values", bandindex);
1113  MemoryContextSwitchTo(oldcontext);
1114  SRF_RETURN_DONE(funcctx);
1115  }
1116 
1117  /* get histogram */
1118  hist = rt_band_get_histogram(stats, bin_count, bin_width, bin_width_count, right, min, max, &count);
1119  if (bin_width_count) pfree(bin_width);
1120  pfree(stats);
1121  if (NULL == hist || !count) {
1122  elog(NOTICE, "Cannot compute histogram for band at index %d", bandindex);
1123  MemoryContextSwitchTo(oldcontext);
1124  SRF_RETURN_DONE(funcctx);
1125  }
1126 
1127  POSTGIS_RT_DEBUGF(3, "%d bins returned", count);
1128 
1129  /* Store needed information */
1130  funcctx->user_fctx = hist;
1131 
1132  /* total number of tuples to be returned */
1133  funcctx->max_calls = count;
1134 
1135  /* Build a tuple descriptor for our result type */
1136  if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE) {
1137  ereport(ERROR, (
1138  errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1139  errmsg(
1140  "function returning record called in context "
1141  "that cannot accept type record"
1142  )
1143  ));
1144  }
1145 
1146  BlessTupleDesc(tupdesc);
1147  funcctx->tuple_desc = tupdesc;
1148 
1149  MemoryContextSwitchTo(oldcontext);
1150  }
1151 
1152  /* stuff done on every call of the function */
1153  funcctx = SRF_PERCALL_SETUP();
1154 
1155  call_cntr = funcctx->call_cntr;
1156  max_calls = funcctx->max_calls;
1157  tupdesc = funcctx->tuple_desc;
1158  hist2 = funcctx->user_fctx;
1159 
1160  /* do when there is more left to send */
1161  if (call_cntr < max_calls) {
1162  Datum values[VALUES_LENGTH];
1163  bool nulls[VALUES_LENGTH];
1164  HeapTuple tuple;
1165  Datum result;
1166 
1167  POSTGIS_RT_DEBUGF(3, "Result %d", call_cntr);
1168 
1169  memset(nulls, FALSE, sizeof(bool) * VALUES_LENGTH);
1170 
1171  values[0] = Float8GetDatum(hist2[call_cntr].min);
1172  values[1] = Float8GetDatum(hist2[call_cntr].max);
1173  values[2] = Int64GetDatum(hist2[call_cntr].count);
1174  values[3] = Float8GetDatum(hist2[call_cntr].percent);
1175 
1176  /* build a tuple */
1177  tuple = heap_form_tuple(tupdesc, values, nulls);
1178 
1179  /* make the tuple into a datum */
1180  result = HeapTupleGetDatum(tuple);
1181 
1182  SRF_RETURN_NEXT(funcctx, result);
1183  }
1184  /* do when there is no more left */
1185  else {
1186  pfree(hist2);
1187  SRF_RETURN_DONE(funcctx);
1188  }
1189 }
VALUES_LENGTH
#define VALUES_LENGTH
Definition: rtpg_statistics.c:2406
rt_band_t
Definition: librtcore.h:2264
rt_raster_get_num_bands
int rt_raster_get_num_bands(rt_raster raster)
Definition: rt_raster.c:372
rt_bandstats_t::count
uint32_t count
Definition: librtcore.h:2311
rtrowdump.raster
raster
Be careful!! Zeros function&#39;s input parameter can be a (height x width) array, not (width x height): ...
Definition: rtrowdump.py:121
ovdump.band
band
Definition: ovdump.py:57
FLT_EQ
#define FLT_EQ(x, y)
Definition: librtcore.h:2185
rt_band_destroy
void rt_band_destroy(rt_band band)
Destroy a raster band.
Definition: rt_band.c:242
POSTGIS_RT_DEBUGF
#define POSTGIS_RT_DEBUGF(level, msg,...)
Definition: rtpostgis.h:65
uint32_t
unsigned int uint32_t
Definition: uthash.h:78
rt_bandstats_t
Definition: librtcore.h:2309
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.count
int count
Definition: genraster.py:56
rt_bandstats_t::values
double * values
Definition: librtcore.h:2319
rt_raster_destroy
void rt_raster_destroy(rt_raster raster)
Release memory associated to a raster.
Definition: rt_raster.c:82
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
FALSE
#define FALSE
Definition: dbfopen.c:168
rt_raster_serialized_t
Struct definitions.
Definition: librtcore.h:2201
rt_histogram_t
Definition: librtcore.h:2324
rt_band_get_histogram
rt_histogram rt_band_get_histogram(rt_bandstats stats, int bin_count, double *bin_widths, int bin_widths_count, int right, double min, double max, uint32_t *rtn_count)
Count the distribution of data.
Definition: rt_statistics.c:412
rt_raster_t
Definition: librtcore.h:2235
POSTGIS_RT_DEBUG
#define POSTGIS_RT_DEBUG(level, msg)
Definition: rtpostgis.h:61
TRUE
#define TRUE
Definition: dbfopen.c:169
rt_raster_deserialize
rt_raster rt_raster_deserialize(void *serialized, int header_only)
Return a raster from a serialized form.
Definition: rt_serialize.c:717
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