R: Map Duplicate Entries to Unique Entries

uniquemap.default {spatstat.geom} | R Documentation

## Map Duplicate Entries to Unique Entries

### Description

Determine whether entries in a vector (or rows in a matrix or data frame) are duplicated, choose a unique representative for each set of duplicates, and map the duplicates to the unique representative.

### Usage

    ## Default S3 method:
    uniquemap(x)

    ## S3 method for class 'data.frame'
    uniquemap(x)

    ## S3 method for class 'matrix'
    uniquemap(x)

### Arguments

`x` | A vector, data frame or matrix, or another type of data.

### Details

The function `uniquemap` is generic, with methods for point patterns, data frames, and a default method.

The default method expects a vector. It determines whether any entries of the vector `x` are duplicated, and constructs a mapping of the indices of `x` so that all duplicates are mapped to a unique representative index.

The result is an integer vector `u` such that `u[j] = i` if the entries `x[i]` and `x[j]` are identical and point `i` has been chosen as the unique representative. The entry `u[i] = i` means either that point `i` is unique, or that it has been chosen as the unique representative of its equivalence class.

The method for `data.frame` determines whether any rows of the data frame `x` are duplicated, and constructs a mapping of the row indices so that all duplicate rows are mapped to a unique representative row.

### Value

An integer vector.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au, Rolf Turner r.turner@auckland.ac.nz and Ege Rubak rubak@math.aau.dk.

### See Also

`uniquemap`, `uniquemap.ppp`

### Examples

      x <- c(3, 5, 2, 4, 2, 3)
      uniquemap(x)

      df <- data.frame(A=x, B=42)
      uniquemap(df)

      z <- cbind(x, 10-x)
      uniquemap(z)

[Package spatstat.geom version 2.2-0 Index]