Variance and Covariance Surfaces for a Functional Data Object
Variance and Covariance Surfaces for a Functional Data Object
DESCRIPTION:
Compute the variance and covariance functions for
functional data. These are two-argument functions, and therefore define
a surface. If there is one functional data object supplied, its variance
is computed. If there are two, the covariance between the two is
computed. Both functional data objects must be univariate.
USAGE:
var.fd(fdx, fdy=fdx)
REQUIRED ARGUMENTS:
- fdx
-
A univariate functional data object.
OPTIONAL ARGUMENTS:
- fdy
-
A univariate functional data object.
VALUE:
A two-argument functional data object representing the variance
surface for a single functional data object or the covariance
between two functional data objects.
SEE ALSO:
mean.fd, std.fd
EXAMPLES: