explode {GEOmap}

Explode Points

Description

Explode a set of points away from a center point

Usage

explode(fxy, dixplo=1, mult=1, cenx=0, ceny=0, PLOT=FALSE)

Arguments

fxy

list of x, y coordinates

dixplo

distance to explode

mult

multiplier for the distance

cenx

x coordinate center of explosion

ceny

y coordinate center of explosion

PLOT

logical, TRUE=make a plot of the resulting explosion

Details

If cenx and ceny is missing it is assumed to be the mean of the coordinates. Program calculates the new locations radiating away from the central point. No protection against overlapping symbols is included.

Value

list of new x,y values

x

new x coordinates

y

new y coordinates

Author(s)

Jonathan M. Lees<[e-mail]>

See Also

ExplodeSymbols, NoOverlap

Examples

############  random data
x = rnorm(20)
y = rnorm(20)

NEW = explode(list(x=x,y=y), dixplo =1)

plot(range(c(x,NEW$x)), range(c(y,NEW$y)), asp=1, type='n')
segments(x,y,NEW$x, NEW$y)
points(x,y, pch=3, col='red')
points(NEW$x, NEW$y, pch=6, col='blue', cex=2)


###  try a larger radius:
NEW2 = explode(list(x=x,y=y), dixplo =1.3)
points(NEW2$x, NEW2$y, pch=7, col='brown', cex=2, xpd=TRUE)
arrows(NEW$x, NEW$y,NEW2$x, NEW2$y, col='green' )



#####   try with a different center
cenx=-1; ceny=-1
NEW = explode(list(x=x,y=y), dixplo =1, cenx=cenx, ceny=ceny)
plot(range(c(x,NEW$x)), range(c(y,NEW$y)), asp=1, type='n')
points(x,y, pch=3, col='red')
segments(x,y,NEW$x, NEW$y)
points(NEW$x, NEW$y, pch=6, col='blue', cex=2)
points(cenx, ceny, pch=8, col='purple')
text(cenx, ceny, labels="Center Point", pos=1)