spacecloud {sgeostat}

Variogram Cloud

Description

Create a scatter plot of square-root or squared differences between variable values at pairs of points versus the distance between the points.

Usage

spacecloud(point.obj, pair.obj, a1, a2, type='r', query.a, ...)

Arguments

point.obj

a point object generated by point()

pair.obj

a pair object generated by pair()

a1

a variable to plot

a2

an optional variable name, if entered the plot will be created between a1 and a2

type

either 'r' for square-root differences or 's' for squared differences

query.a

an optional variable name, if entered, the value of the variable will be displayed on the graphics device for points identified by the user.

...

additional arguments for plot

Value

NULL

Note

When query.a is entered, the user will be prompted to identify points on the display device. Because each point in the plot represents a pair of locations, the user must identify each point twice, once for the "from" point and once for the "to" point. Querying is ended by pressing the middle mouse button on the mouse while the cursor is in the display window.

References

http://www.gis.iastate.edu/SGeoStat/homepage.html

See Also

point, pair

Examples

opar <- par(ask = interactive() && .Device == "X11")
spacecloud(maas.point,maas.pair,'zinc')
# identify some points:
spacecloud(maas.point,maas.pair,'zinc',query.a='zinc')
par(opar)