mvl_write_spatial_index1: Write spatial group information for each row

In RMVL: Mappable Vector Library for Handling Large Datasets

Write spatial group information for each row

Description

This function is passed a list of MVL vectors which are interpreted in data.frame fashion. These rows are split into groups so that identical rows are guaranteed to belong to the same group. This is done using partition into equal sized bins. This function is meant for constructing spatial indexes.

Usage

mvl_write_spatial_index1(MVLHANDLE, L, bits, name = NULL)

Arguments

MVLHANDLE	a handle to MVL file produced by mvl_open()
L	list of vector like MVL_OBJECTs
bits	a vector of bit values to use for each member of L
name	if specified add a named entry to MVL file directory

Value

an object of class MVL_OFFSET that describes an offset into this MVL file. MVL offsets are vectors and can be concatenated. They can be written to MVL file directly, or as part of another object such as list.

See Also

mvl_order_vectors, mvl_find_matches, mvl_group, mvl_find_matches, mvl_indexed_copy, mvl_merge, mvl_hash_vectors, mvl_get_groups

Examples

## Not run: 
Mtmp<-mvl_open("tmp_a.mvl", append=TRUE, create=TRUE)
mvl_write_object(Mtmp, data.frame(x=runif(100), y=1:100), "df1")
Mtmp<-mvl_remap(Mtmp)
mvl_write_spatial_index1(Mtmp, list(Mtmp$df1[,"x",ref=TRUE], Mtmp$df1[,"y", ref=TRUE]),
                                                             c(2, 3), "df1_sp_groups")
Mtmp<-mvl_remap(Mtmp)
print(mvl_get_neighbors(Mtmp["df1_sp_groups", ref=TRUE], list(c(0.5, 0.6), c(2, 3))))

## End(Not run)

RMVL documentation built on Feb. 23, 2025, 3:01 a.m.