Raster_merge

grid-functions raster_merge

syntax

• raster_merge(target_grid_domain, valuesunit,sub_grid_data_item_1, …, sub_grid_data_item_n)
• raster_merge(indexmap, valuesunit, valuesunit,sub_grid_data_item_1, …, sub_grid_data_item_n)

definition

raster_merge(target_grid_domain, valuesunit, sub_grid_data_item_1,…, sub_grid_data_item_n) results in raster-data merged from the given sub_grid_data_items.

• The domain-unit of the resulting data-item is configured as first argument.
• The values-unit of the resulting data item is configured as second argument.

This variant can be used if the projection information can be derived from the domain units of the sub_grid domains and the cell size of the target_grid_domain equals the cell size of the sub_grid domains. This raster_merge variant can be used both to merge data from smaller sub_grid domains to a larger target grid domains or vice versa.

raster_merge(indexmap, valuesunit, valuesunit, sub_grid_data_item_1, …, sub_grid_data_item_n) results in raster-data merged from the given sub_grid_data_items.

• The domain unit of the resulting item is equal to the domain unit of the first argument indexmap. This indexmap argument contains sequence numbers of the configured sub_grid_data_items, 0 refers to sub_grid_data_item_1, 1 to sub_grid_data_item_1, …, n-1 tosub_grid_data_item_n..
• The values unit of the resulting data item is configured as second argument.

At locations with indexmap values >= n or outside the range of the domain unit of the indicated sub_grid, the result will be null.

applies to

• attribute indexmap with uint16 value-type
• valuesunit must have a numeric value type
• sub_grid_data_item_1, …, sub_grid_data_item_n must have the same values unit
• The value type of the target_grid_domain and the sub_grids must match.

conditions

1. The indexmap argument must have a domain unit with a Point value type of the group CanBeDomainUnit.
2. all sub_grid_data_items must have a domain unit with a Point value type of the group CanBeDomainUnit.
3. all sub_grids must have a compatible projections as the target_grid_domain and the domain unit of the indexmap argument.

since

• raster_merge(target_domain, valuesunit, subgrid_1, …, subgrid_n): 7.101
• raster_merge(indexmap, valuesunit, subgrid_1, …, subgrid_n): 7.013

example

attribute<uint16> indexmap (DomainM) :=
  switch(
     case(pointRow(id(DomainM)) <  2s && pointCol(id(DomainM)) <  2s, 0)
    ,case(pointRow(id(DomainM)) >= 2s && pointCol(id(DomainM)) <  2s, 1)
    ,case(pointRow(id(DomainM)) >= 2s && pointCol(id(DomainM)) >= 2s, 2)
    ,3
  );

container SubGrids
{
   unit<spoint> DomainA := range(DomainM, point(0s,0s), point(2s,2s));
   unit<spoint> DomainB := range(DomainM, point(2s,0s), point(5s,2s));
   unit<spoint> DomainC := range(DomainM, point(3s,2s), point(5s,5s));
   unit<spoint> DomainD := range(DomainM, point(0s,2s), point(3s,5s));
}

unit<uint8> codes;

attribute<codes> ToBeMergedI   (SubGrids/DomainA) := const(10, SubGrids/DomainA, codes);
attribute<codes> ToBeMergedII  (SubGrids/DomainB) := const(20, SubGrids/DomainB, codes);
attribute<codes> ToBeMergedIII (SubGrids/DomainC) := const(30, SubGrids/DomainC, codes);
attribute<codes> ToBeMergedIV  (SubGrids/DomainD) := const(40, SubGrids/DomainD, codes);

Example I:
attribute<codes> raster_merged (DomainM) := 
   raster_merge(DomainM, codes, ToBeMergedI, ToBeMergedII, ToBeMergedIII, ToBeMergedIV);

Example II:
attribute<codes> raster_merged (DomainM) := 
   raster_merge(indexmap,codes, ToBeMergedI, ToBeMergedII, ToBeMergedIII, ToBeMergedIV);

indexmap

DomainM, nr of rows = 5, nr of cols = 5

ToBeMergedI

DomainA, nr of rows = 2, nr of cols = 2

ToBeMergedII

DomainB, nr of rows = 3, nr of cols = 2

ToBeMergedIII

DomainC, nr of rows = 2, nr of cols = 3

ToBeMergedIV

DomainD, nr of rows = 3, nr of cols = 3

raster_merged

DomainM, nr of rows = 5, nr of cols = 5

See also

• merge