Locates duplicated coordinates
This funtions takes an object with 2-D coordinates and returns the
positions of the duplicated coordinates. Also sets a method
for duplicated
dup.coords(x, ...) ## Default S3 method: dup.coords(x, ...) ## S3 method for class 'geodata' dup.coords(x, incomparables, ...) ## S3 method for class 'geodata' duplicated(x, incomparables, ...)
x |
a two column numeric matrix or data frame. |
incomparables |
unused. Just for compatibility with
the generic function |
... |
arguments passed to |
Function and methods returns NULL if there are no duplicates
locations.
Otherwise, the default method returns a list where each component is a vector with the positions or the rownames, if available, of the duplicates coordinates.
The method for geodata returns a data-frame with
rownames equals to the positions of the duplicated coordinates,
the first column is a factor indicating duplicates and
the remaning are output of as.data.frame.geodata.
Paulo Justiniano Ribeiro Jr. paulojus@leg.ufpr.br
Peter J. Diggle p.diggle@lancaster.ac.uk.
as.geodata for the definition of geodata class,
duplicated for the base function to identify duplicated
values and jitterDupCoords for a function which jitters
duplicated coordinates.
## simulating data dt <- grf(30, cov.p=c(1, .3)) ## "forcing" some duplicated locations dt$coords[4,] <- dt$coords[14,] <- dt$coords[24,] <- dt$coords[2,] dt$coords[17,] <- dt$coords[23,] <- dt$coords[8,] ## output of the method for geodata dup.coords(dt) ## which is the same as a method for duplicated() duplicated(dt) ## the default method: dup.coords(dt$coords)
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