approx3d {oce} | R Documentation |
Interpolate within a 3D array, using the trilinear approximation.
approx3d(x, y, z, f, xout, yout, zout)
x |
vector of x values for grid (must be equi-spaced) |
y |
vector of y values for grid (must be equi-spaced) |
z |
vector of z values for grid (must be equi-spaced) |
f |
matrix of rank 3, with the gridd values mapping to the |
xout |
vector of x values for output. |
yout |
vector of y values for output (length must match that of
|
zout |
vector of z values for output (length must match that of
|
Trilinear interpolation is used to interpolate within the f
array,
for those (xout
, yout
and zout
) triplets that are
inside the region specified by x
, y
and z
. Triplets
that lie outside the range of x
, y
or z
result in
NA
values.
A vector of interpolated values (or NA
values), with length
matching that of xout
.
Dan Kelley and Clark Richards
## set up a grid library(oce) n <- 5 x <- seq(0, 1, length.out=n) y <- seq(0, 1, length.out=n) z <- seq(0, 1, length.out=n) f <- array(1:n^3, dim=c(length(x), length(y), length(z))) ## interpolate along a diagonal line m <- 100 xout <- seq(0, 1, length.out=m) yout <- seq(0, 1, length.out=m) zout <- seq(0, 1, length.out=m) approx <- approx3d(x, y, z, f, xout, yout, zout) ## graph the results plot(xout, approx, type='l') points(xout[1], f[1, 1, 1]) points(xout[m], f[n,n,n])