ribbon.plot {fields}

Adds to an existing plot, a ribbon of color, based on values from a color scale, along a sequence of line segments.

Description

Given a series of 2-d points and values at these segments, the function colors the segments according to a color scale and the segment values. This is essentially an image plot restricted to line segments.

Usage

ribbon.plot(x,y,z,zlim=NULL, col=tim.colors(256),
               transparent.color="white",...)

Arguments

x

x locations of line segments

y

y locations of line segments

z

Values associated with each segment.

zlim

Range for z values to determine color scale.

col

Color table used for strip. Default is our favorite tim.colors being a scale from a dark blue to dark red.

transparent.color

Color used for missing values. Default is that missing values make the ribbon transparent.

...

Optional graphical arguments that are passed to the segment plotting function. A favorite is lwd to make a broad ribbon.

Details

Besides possible 2-d applications, this function is useful to annotate a curve on a surface using colors. The values mapped to acolor scheme could indicate a feature other than the height of the surface. For example, this function could indicate the slope of the surface.

Author(s)

Doug Nychka

See Also

image.plot, arrow.plot, add.image, colorbar.plot

Examples

plot( c(-1.5,1.5),c(-1.5,1.5), type="n")
temp<- list( x= seq( -1,1,,40), y= seq( -1,1,,40))
temp$z <- outer( temp$x, temp$y, "+")
contour( temp, add=TRUE)

t<- seq( 0,.5,,50)
y<- sin( 2*pi*t)
x<- cos( pi*t)
z<- x + y

ribbon.plot( x,y,z, lwd=10)

persp(  temp, phi=15, shade=.8, col="grey")-> pm
trans3d( x,y,z,pm)-> uv
ribbon.plot( uv$x, uv$y, z**2,lwd=5)