# uniquemap.default: Map Duplicate Entries to Unique Entries In spatstat.geom: Geometrical Functionality of the 'spatstat' Family

## 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

 ```1 2 3 4 5 6 7 8``` ```## 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)

\spatstatAuthors

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`uniquemap`, `uniquemap.ppp`
 ```1 2 3 4 5 6 7 8``` ``` 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) ```