PostGIS  2.5.1dev-r@@SVN_REVISION@@

◆ RASTER_summaryStats()

Datum RASTER_summaryStats ( PG_FUNCTION_ARGS  )

Definition at line 73 of file rtpg_statistics.c.

References ovdump::band, rt_bandstats_t::count, FALSE, FLT_EQ, rt_bandstats_t::max, rt_bandstats_t::mean, rt_bandstats_t::min, PG_FUNCTION_INFO_V1(), rtrowdump::raster, RASTER_summaryStatsCoverage(), rt_band_destroy(), rt_band_get_summary_stats(), rt_raster_deserialize(), rt_raster_destroy(), rt_raster_get_band(), rt_raster_get_num_bands(), rt_bandstats_t::stddev, rt_bandstats_t::sum, TRUE, and VALUES_LENGTH.

74 {
75  rt_pgraster *pgraster = NULL;
76  rt_raster raster = NULL;
77  rt_band band = NULL;
78  int32_t bandindex = 1;
79  bool exclude_nodata_value = TRUE;
80  int num_bands = 0;
81  double sample = 0;
82  rt_bandstats stats = NULL;
83 
84  TupleDesc tupdesc;
85  Datum values[VALUES_LENGTH];
86  bool nulls[VALUES_LENGTH];
87  HeapTuple tuple;
88  Datum result;
89 
90  /* pgraster is null, return null */
91  if (PG_ARGISNULL(0))
92  PG_RETURN_NULL();
93  pgraster = (rt_pgraster *) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
94 
95  raster = rt_raster_deserialize(pgraster, FALSE);
96  if (!raster) {
97  PG_FREE_IF_COPY(pgraster, 0);
98  elog(ERROR, "RASTER_summaryStats: Cannot deserialize raster");
99  PG_RETURN_NULL();
100  }
101 
102  /* band index is 1-based */
103  if (!PG_ARGISNULL(1))
104  bandindex = PG_GETARG_INT32(1);
105  num_bands = rt_raster_get_num_bands(raster);
106  if (bandindex < 1 || bandindex > num_bands) {
107  elog(NOTICE, "Invalid band index (must use 1-based). Returning NULL");
108  rt_raster_destroy(raster);
109  PG_FREE_IF_COPY(pgraster, 0);
110  PG_RETURN_NULL();
111  }
112 
113  /* exclude_nodata_value flag */
114  if (!PG_ARGISNULL(2))
115  exclude_nodata_value = PG_GETARG_BOOL(2);
116 
117  /* sample % */
118  if (!PG_ARGISNULL(3)) {
119  sample = PG_GETARG_FLOAT8(3);
120  if (sample < 0 || sample > 1) {
121  elog(NOTICE, "Invalid sample percentage (must be between 0 and 1). Returning NULL");
122  rt_raster_destroy(raster);
123  PG_FREE_IF_COPY(pgraster, 0);
124  PG_RETURN_NULL();
125  }
126  else if (FLT_EQ(sample, 0.0))
127  sample = 1;
128  }
129  else
130  sample = 1;
131 
132  /* get band */
133  band = rt_raster_get_band(raster, bandindex - 1);
134  if (!band) {
135  elog(NOTICE, "Cannot find band at index %d. Returning NULL", bandindex);
136  rt_raster_destroy(raster);
137  PG_FREE_IF_COPY(pgraster, 0);
138  PG_RETURN_NULL();
139  }
140 
141  /* we don't need the raw values, hence the zero parameter */
142  stats = rt_band_get_summary_stats(band, (int) exclude_nodata_value, sample, 0, NULL, NULL, NULL);
143  rt_band_destroy(band);
144  rt_raster_destroy(raster);
145  PG_FREE_IF_COPY(pgraster, 0);
146  if (NULL == stats) {
147  elog(NOTICE, "Cannot compute summary statistics for band at index %d. Returning NULL", bandindex);
148  PG_RETURN_NULL();
149  }
150 
151  /* Build a tuple descriptor for our result type */
152  if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE) {
153  ereport(ERROR, (
154  errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
155  errmsg(
156  "function returning record called in context "
157  "that cannot accept type record"
158  )
159  ));
160  }
161 
162  BlessTupleDesc(tupdesc);
163 
164  memset(nulls, FALSE, sizeof(bool) * VALUES_LENGTH);
165 
166  values[0] = Int64GetDatum(stats->count);
167  if (stats->count > 0) {
168  values[1] = Float8GetDatum(stats->sum);
169  values[2] = Float8GetDatum(stats->mean);
170  values[3] = Float8GetDatum(stats->stddev);
171  values[4] = Float8GetDatum(stats->min);
172  values[5] = Float8GetDatum(stats->max);
173  }
174  else {
175  nulls[1] = TRUE;
176  nulls[2] = TRUE;
177  nulls[3] = TRUE;
178  nulls[4] = TRUE;
179  nulls[5] = TRUE;
180  }
181 
182  /* build a tuple */
183  tuple = heap_form_tuple(tupdesc, values, nulls);
184 
185  /* make the tuple into a datum */
186  result = HeapTupleGetDatum(tuple);
187 
188  /* clean up */
189  pfree(stats);
190 
191  PG_RETURN_DATUM(result);
192 }
#define VALUES_LENGTH
uint16_t rt_raster_get_num_bands(rt_raster raster)
Definition: rt_raster.c:372
uint32_t count
Definition: librtcore.h:2360
raster
Be careful!! Zeros function&#39;s input parameter can be a (height x width) array, not (width x height): ...
Definition: rtrowdump.py:121
band
Definition: ovdump.py:57
#define FLT_EQ(x, y)
Definition: librtcore.h:2234
void rt_band_destroy(rt_band band)
Destroy a raster band.
Definition: rt_band.c:340
rt_band rt_raster_get_band(rt_raster raster, int bandNum)
Return Nth band, or NULL if unavailable.
Definition: rt_raster.c:381
void rt_raster_destroy(rt_raster raster)
Release memory associated to a raster.
Definition: rt_raster.c:82
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.
#define FALSE
Definition: dbfopen.c:168
Struct definitions.
Definition: librtcore.h:2250
#define TRUE
Definition: dbfopen.c:169
rt_raster rt_raster_deserialize(void *serialized, int header_only)
Return a raster from a serialized form.
Definition: rt_serialize.c:725
Here is the call graph for this function: