PlotVectors {CircSpatial}R Documentation

Vector Plots

Description

PlotVectors plots vector-spatial data as unit vectors, vectors, or triangle icons with or without jittering. Triangle icons have area proportional to vector magnitude. Jittering can be help clarify structure when vectors overlap.

Usage

PlotVectors(x, y, h, v, UnitVector=TRUE, TriIcon=FALSE,
  AdjArrowLength=1, AdjHeadLength=1, TriIconAdj=1, TriRatio=4,
  JitterPlot=FALSE, Jitter=1, ...)

Arguments

x Vector of x coordinates
y Vector of y coordinates
h Vector of horizontal component
v Vector of vertical comonent
UnitVector TRUE or FALSE, see Details
TriIcon TRUE or FALSE, see Details
AdjArrowLength Arrow length multiplier
AdjHeadLength Arrow head length multiplier
TriIconAdj Multiplies size of icons
TriRatio Length to width ratio of triangle icon
JitterPlot If TRUE add jitter to location coordinates
Jitter Amount of jitter=Jitter x runif value
... Additional parameters for plotting

Details

Section J.11 in Appendices.J.PackageDocumentation in the installed folder doc provides
additional detail and illustrations.

Missing values are permitted in h and/or v. u=v=0 are filted and not plotted.

UnitVector TriIcon Plot Output
FALSE FALSE Direction and magnitude as variable length arrow
TRUE FALSE Direction as constant length arrow
FALSE TRUE Triangle icons with area proportional to magnitude
TRUE TRUE Direction as constant length arrow

Value

Plot of vector-spatial data. No values are returned.

Warning

Excessive jitter can mask directional structure. The arrow.plot function produces warning
messages about zero-length vectors for non-zero vectors.

Author(s)

Bill Morphet

References

Ware, C. (2004), Information Visualization, 2nd ed., Morgan Kauffman, San Francisco,
p. 201-205.

See Also

OceanWind

Examples

data(OceanWind)
wind.1997.Jan <- OceanWind[OceanWind$year>1997 & OceanWind$year<1997.1,
  -1]

## Direction Only
PlotVectors(x=wind.1997.Jan$x, y=wind.1997.Jan$y, h=wind.1997.Jan$u,
  v=wind.1997.Jan$v, UnitVector=TRUE, AdjArrowLength=0.75,
  AdjHeadLength=0.75, xlim=c(320,350), ylim=c(0,30))

## Direction and Magnitude
PlotVectors(x=wind.1997.Jan$x, y=wind.1997.Jan$y, h=wind.1997.Jan$u,
  v=wind.1997.Jan$v, UnitVector=FALSE, TriIcon=FALSE, AdjArrowLength=3,
  AdjHeadLength=0.4, xlim=c(320,350), ylim=c(0,30))

## Triangle Icons
PlotVectors(x=wind.1997.Jan$x, y=wind.1997.Jan$y, h=wind.1997.Jan$u,
  v=wind.1997.Jan$v, UnitVector=FALSE, TriIcon=TRUE, TriIconAdj=0.25,
  TriRatio=4, xlim=c(320,350), ylim=c(0,30))

[Package CircSpatial version 1.0 Index]