DPTMAP procedure

Draws maps for spatial point patterns using high-resolution graphics (M.A. Mugglestone, S.A. Harding, B.Y.Y. Lee, P.J. Diggle & B.S. Rowlingson).


Options

TITLE = text
Main title for the plot; default *

WINDOW = scalar
Which graphics window to use for the plot; default 1

KEYWINDOW = scalar
Which graphics window to use for the key; default 2

YTITLE = text
Title for the vertical axis; default *

XTITLE = text
Title for the horizontal axis; default *

YLOWER = scalar
Lower limit for the vertical axis

YUPPER = scalar
Upper limit for the vertical axis

XLOWER = scalar
Lower limit for the horizontal axis

XUPPER = scalar
Upper limit for the horizontal axis

SCREEN = string
Whether to clear the screen before plotting or to continue plotting on the old screen (clear, keep); default clea

KEYDESCRIPTION = text
Overall description for the key; default *

ENDACTION = string
Action to be taken after completing the plot (continue, pause); default paus


Parameters

Y = variates
Vertical coordinates of one or more spatial point patterns; no default - this parameter must be set

X = variates
Horizontal coordinates of one or more spatial point patterns; no default - this parameter must be set

PEN = scalars or variates or factors
Pen number for each graph

DESCRIPTION = texts
Annotation for the key


Description

DPTMAP is a specially adapted version of DGRAPH designed for producing maps of spatial point patterns. The procedure uses the AXES and FRAME directives to set up axes with equal scales. Options YLOWER, YUPPER, XLOWER and XUPPER can be used to specify bounds for the axes, or these can be set automatically. The axes are made to extend slightly beyond the range of values to be plotted, and are drawn using the box style. The parameters X and Y specify pointers to variates containing the horizontal and vertical coordinates of one or more spatial point patterns. Titles for the horizontal and vertical axes can be specified using the XTITLE and YTITLE options, respectively. Options TITLE, WINDOW, KEYWINDOW, SCREEN, KEYDESCRIPTION and ENDACTION are as in DGRAPH.

 

Options: TITLE, WINDOW, KEYWINDOW, YTITLE, XTITLE, YLOWER, YUPPER, XLOWER, XUPPER, SCREEN, KEYDESCRIPTION, ENDACTION.

Parameters: Y, X, PEN, DESCRIPTION.


Method

A procedure PTCHECKXY is called to check that each pair of structures in X and Y have identical restrictions. If any of YLOWER, XUPPER, YLOWER and YUPPER are unset, the procedure PTBOX is used to assign suitable values based on the data in X and Y. The values of these options are then adjusted to extend the range of the axes and so produce a more attractive plot. The adjusted values are given by

XLOWER - 0.05 * range(X),

XUPPER + 0.05 * range(X),

YLOWER - 0.05 * range(Y),

YUPPER + 0.05 * range(Y),

where range(X) is the range of values in X and range(Y) is the range of values in Y. The AXES directive is then used to set up box-style axes with the required upper and lower limits and titles specified by XTITLE and YTITLE. The FRAME directive is used to ensure equal scales on the horizontal and vertical axes. Finally, the DGRAPH directive is used to draw the map on the current graphics device.


Action with RESTRICT

If any of the variates in X and Y are restricted, only the subset of values specified by the restriction will be included in the graph.