- dfxy
a data frame containing the two columns for the axes

- fac
a factor partioning the rows of the data frame in classes

- xax
the column number of x in `dfxy`

- yax
the column number of y in `dfxy`

- optchull
the number of convex hulls and their interval

- label
a vector of strings of characters for the point labels

- clabel
if not NULL, a character size for the labels, used with `par("cex")*clabel`

- cpoint
a character size for plotting the points, used with `par("cex")*cpoint`

. If zero, no points are drawn

- col
a vector of colors used to draw each class in a different color

- xlim
the ranges to be encompassed by the x axis, if NULL, they are computed

- ylim
the ranges to be encompassed by the y axis, if NULL they are computed

- grid
a logical value indicating whether a grid in the background of the plot should be drawn

- addaxes
a logical value indicating whether the axes should be plotted

- origin
the fixed point in the graph space, for example c(0,0) the origin axes

- include.origin
a logical value indicating whether the point "origin" should be belonged to the graph space

- sub
a string of characters to be inserted as legend

- csub
a character size for the legend, used with `par("cex")*csub`

- possub
a string of characters indicating the sub-title position ("topleft", "topright", "bottomleft", "bottomright")

- cgrid
a character size, parameter used with par("cex")* `cgrid`

to indicate the mesh of the grid

- pixmap
an object 'pixmap' displayed in the map background

- contour
a data frame with 4 columns to plot the contour of the map : each row gives a segment (x1,y1,x2,y2)

- area
a data frame of class 'area' to plot a set of surface units in contour

- add.plot
if TRUE uses the current graphics window