Create a Polygonal Basis
A basis is set up for constructing polygonal lines, consisting of straight line segments that join together.
create.polygonal.basis(rangeval=NULL, argvals=NULL, dropind=NULL, quadvals=NULL, values=NULL, basisvalues=NULL, names='polygon', axes=NULL)
rangeval |
a numeric vector of length 2 defining the interval over which the
functional data object can be evaluated; default value is
If If length(rangeval)>2 and |
argvals |
a strictly increasing vector of argument values at which line segments join to form a polygonal line. |
dropind |
a vector of integers specifiying the basis functions to be dropped, if any. For example, if it is required that a function be zero at the left boundary, this is achieved by dropping the first basis function, the only one that is nonzero at that point. |
quadvals |
a matrix with two columns and a number of rows equal to the number
of quadrature points for numerical evaluation of the penalty
integral. The first column of |
values |
a list containing the basis functions and their derivatives
evaluated at the quadrature points contained in the first
column of |
basisvalues |
A list of lists, allocated by code such as vector("list",1). This
is designed to avoid evaluation of a basis system repeatedly
at a set of argument values. Each sublist corresponds to a specific
set of argument values, and must have at least two components, which
may be named as you wish. The first component of a sublist contains
the argument values. The second component contains a matrix of
values of the basis functions evaluated at the arguments in the
first component. The third and subsequent components, if present,
contain matrices of values their derivatives up to a maximum
derivative order. Whenever function basisobj\$basisvalues <- vector("list",1) basisobj\$basisvalues[[1]] <- list(args=evalargs, values=basismat) |
names |
either a character vector of the same length as the number of basis
functions or a single character string to which |
axes |
an optional list used by selected |
The actual basis functions consist of triangles, each with its apex over an argument value. Note that in effect the polygonal basis is identical to a B-spline basis of order 2 and a knot or break value at each argument value. The range of the polygonal basis is set to the interval defined by the smallest and largest argument values.
a basis object with the type polyg
.
# Create a polygonal basis over the interval [0,1] # with break points at 0, 0.1, ..., 0.95, 1 (basisobj <- create.polygonal.basis(seq(0,1,0.1))) # plot the basis plot(basisobj)
Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.