BivariateInterpolation {fUtilities} | R Documentation |
A collection and description of functions which
allow to interpolate and smooth bivariate irregular
data sets including linear interpolation, Akima
spline interpolation, and kriging.
Gridded Interpolation Functions:
linearInterp | performs linear spline interpolation, |
akimaInterp | performs Akima spline interpolation, |
krigeInterp | performs krige interpolation. |
Pointwise Interpolation Functions:
linearInterpp | performs linear spline interpolation, |
akimaInterpp | performs Akima spline interpolation |
linearInterp(x, y = NULL, z = NULL, gridPoints = 21, xo = seq(min(x), max(x), length = gridPoints), yo = seq(min(y), max(y), length = gridPoints)) linearInterpp(x, y = NULL, z = NULL, xo, yo) akimaInterp(x, y = NULL, z = NULL, gridPoints = 21, xo = seq(min(x), max(x), length = gridPoints), yo = seq(min(y), max(y), length = gridPoints), extrap = FALSE) akimaInterpp(x, y = NULL, z = NULL, xo, yo, extrap = FALSE) krigeInterp(x, y = NULL, z = NULL, gridPoints = 21, xo = seq(min(x), max(x), length = gridPoints), yo = seq(min(y), max(y), length = gridPoints), extrap = FALSE, polDegree = 6)
x, y, z |
[griddata] - x and y are two numeric vectors of grid pounts
and z is a numeric matrix or any other rectangular object
which can be transformed by the function as.matrix into
a matrix object. [akimaInterp][krigeInterp] - either three numeric vectors of equal length or if y
and z are NULL, a list with entries x , y ,
z , or named data frame with x in the first,
y in the second, and z in the third column. [persp][contour] - x is an pbject of class gridData .
|
gridPoints |
an integer value specifying the number of grid points in x
and y direction.
|
xo, yo |
[*Interp] - two numeric vectors of data points spanning the grid. [*Interpp] - two numeric vectors of data points building pairs for pointwise interpolation. |
extrap |
a logical, if TRUE then the data points are extrapolated.
|
polDegree |
[krige] - the polynomial krige degree, an integer ranging between 1 and 6. |
linearInterp
-
akimaInterp
-
krigeInterp
-
A list with at least three entries, x
, y
and z
.
Note, that the returned values, can be directly used by the
persp.gridData()
and contour.gridData
3D plotting methods.
linearInterpp
-
akimaInterpp
-
A data.frame with columns "x"
, "y"
, and "z"
.
The function krigeInterp
requires loading of the R package
spatial
.
IMPORTANT: The contributed package akima
is not in the
dependence list of the DESCRIPTION file due to license conditions.
The Rmetrics user has to load this package from the CRAN server on
his own responsibility, please check the license conditions.
Diethelm Wuertz for the Rmetrics R-port,
H. Akima for the Fortran Code of the Akima spline interpolation routine.
## Not run: ## akimaInterp - # Akima Interpolation: set.seed(1953) x = runif(999) - 0.5 y = runif(999) - 0.5 z = cos(2*pi*(x^2+y^2)) ans = akimaInterp(x, y, z, extrap = FALSE) persp(ans) contour(ans) ## krigeInterp - # Kriging: ans = krigeInterp(x, y, z, extrap = FALSE) persp(ans) contour(ans) ## End(Not run)