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

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:

classA character vector of class labels.

colA vector of colors used for each class.

pchA vector of plotting symbols used for each class.

## See also

## Examples

clPairs(iris[,1:4], cl = iris$Species)

clp <- clPairs(iris[,1:4], cl = iris$Species, lower.panel = NULL)

clPairsLegend(0.1, 0.4, class = clp$class,
col = clp$col, pch = clp$pch,
title = "Iris data")