.BG
.FN bv
.TL
Compute and Plot Three-Dimensional (Bivariate) Histogram
.DN
Displays a perspective outline of a bivariate histogram.
.CS
bv(x, ab, nbin, eye=c(1, 1, 1), opt=F)
.RA
.AG x
nx2 matrix of input data.
.AG ab
2x2 matrix:  each row contains (binning) range for each variable.
.AG nbin
vector containing number of bins for each variable.
.OA
.AG eye
location of the viewer in Euclidean coordinates
while locating at the point (0,0,0).  A true
perspective is not computed.
.AG opt
(not used)
.RT
list(nc,ab) containing the bivariate bin counts and binning ranges.
.SE
Some graphical parameters are changed (and not restored)
.DT
First compile bv.r (f77 -c bv.r) and then dyn.load("bv.o")
.SH REFERENCES
Scott, D.W. (1992).  Multivariate Density Estimation: Theory,
Practice, and Visualization.  John Wiley & Sons, New York.
.SA
hist2d, ashn
.EX
x <- matrix(rnorm(200),100,2)	# 100 bivariate normal points
ab <- t( apply(x,2,range) )	# extent of data
bv( x, ab, c(15,15), c(2,5,1) )	# pretty view
.KW histogram, bivariate
.WR