Theoretical Variogram Functions

DESCRIPTION:

Computes theoretical isotropic variograms at supplied distance values. Models include exponential, spherical, gaussian, linear and power variograms.

USAGE:

exp.vgram(distance, range, sill=1, nugget=0) 
spher.vgram(distance, range, sill=1, nugget=0) 
gauss.vgram(distance, range, sill=1, nugget=0) 
linear.vgram(distance, slope, nugget=0) 
power.vgram(distance, slope, range=1, nugget=0) 

REQUIRED ARGUMENTS:

distance
a vector of distances to compute the variogram for.
range
the range value for the exponential, spherical and gaussian variograms or the exponent value for the power variogram.
slope
the slope for the variogram, only appropriate for linear.vgram and power.vgram.

OPTIONAL ARGUMENTS:

sill
the sill value for the variogram, only applies to the exponential, spherical and gaussian models. This is the absolute sill, it is the maximum value of the variogram minus any nugget effect.
nugget
the nugget effect.

VALUE:

a vector of variogram values at the supplied distances.

SEE ALSO:

, .

EXAMPLES:

dist <- seq(0,6,length=100) 
plot(dist,spher.vgram(dist,range=3,nugget=.2),type='l')