db.sel {RGeoS}R Documentation

Define a selection

Description

Define a selection in a Data Base

Usage

db.sel(db, ..., combine="set",flag.replace=TRUE)

Arguments

db

The db-class where the selection must be defined

...

String defining the selection. It may specify directly (with no quote) any variable by its name (not its locator).

combine

When a selection already exists, the 'combine' keyword indicates how the current selection must be combined with the previous one.

flag.replace

When a selection already exists and a new selection is created, the previously existing selection is deleted beforehand if this flag is TRUE. Otherwise a new variable is created.

Details

In particular, to set a selection variable where all the samples are constantly TRUE, it suffices to type db.sel(db,TRUE) (resp. FALSE). If the second argument of db.sel is not provided, the active selection (if any) is discarded.

Value

The db-class where the selection has been defined

See Also

db-class


[Package RGeoS version 9.1.1 Index]