# Pairwise Scatter Plots showing Classification

`clPairs.Rd`

Creates a scatter plot for each pair of variables in given data. Observations in different classes are represented by different colors and symbols.

## Usage

```
clPairs(data, classification,
symbols = NULL, colors = NULL, cex = NULL,
labels = dimnames(data)[[2]], cex.labels = 1.5,
gap = 0.2, grid = FALSE, ...)
clPairsLegend(x, y, class, col, pch, cex, box = TRUE, ...)
```

## Arguments

- data
A numeric vector, matrix, or data frame of observations. Categorical variables are not allowed. If a matrix or data frame, rows correspond to observations and columns correspond to variables.

- classification
A numeric or character vector representing a classification of observations (rows) of

`data`

.- symbols
Either an integer or character vector assigning a plotting symbol to each unique class in

`classification`

. Elements in`symbols`

correspond to classes in order of appearance in the sequence of observations (the order used by the function`unique`

). The default is given by`mclust.options("classPlotSymbols")`

.- colors
Either an integer or character vector assigning a color to each unique class in

`classification`

. Elements in`colors`

correspond to classes in order of appearance in the sequence of observations (the order used by the function`unique`

). The default is given by`mclust.options("classPlotColors")`

.- cex
A vector of numerical values specifying the size of the plotting symbol for each unique class in

`classification`

. Values in`cex`

correspond to classes in order of appearance in the sequence of observations (the order used by the function`unique`

). By default`cex = 1`

for all classes is used.- labels
A vector of character strings for labelling the variables. The default is to use the column dimension names of

`data`

.- cex.labels
A numerical value specifying the size of the text labels.

- gap
An argument specifying the distance between subplots (see

`pairs`

).- grid
A logical specifying if grid lines should be added to panels (see

`grid`

).- x,y
The x and y co-ordinates with respect to a graphic device having plotting region coordinates

`par("usr" = c(0,1,0,1))`

.- class
The class labels.

- box
A logical, if

`TRUE`

then a box is drawn around the current plot figure.- col, pch
The colors and plotting symbols appearing in the legend.

- ...
For a

`clPairs`

call may be additional arguments to be passed to`pairs`

. For a`clPairsLegend`

call may be additional arguments to be passed to`legend`

.

## Details

The function `clPairs()`

draws scatter plots on the current graphics device for each combination of variables in `data`

. Observations of different classifications are labeled with different symbols.

The function `clPairsLegend()`

can be used to add a legend. See examples below.

## Value

The function `clPairs()`

invisibly returns a list with the following components:

- class
A character vector of class labels.

- col
A vector of colors used for each class.

- pch
A vector of plotting symbols used for each class.