interp3d

3d spline evaluation function

Calling Sequence

[fp[,dfpdx,dfpdy,dfpdz]]=interp3d(xp,yp,zp,tl,out_mode)

Arguments

:xp, yp, zp real vectors or matrices of same size : :tl tlist of type “splin3d”, defining a 3d tensor spline (called s

in the following)

: :out_mode (optional) string defining the evaluation of s outside

the grid ([xmin,xmax]x[ymin,ymax]x[zmin,zmax])

: :fp vector or matrix of same format than xp, yp and zp,

elementwise evaluation of s on these points.

: :dfpdx, dfpdy, dfpdz vectors (or matrices) of same format than xp,

yp and zp, elementwise evaluation of the first derivatives of s on these points.

:

Description

Given a tlist tl defining a 3d spline function (see `splin3d`_) this function evaluates s (and ds/dx, ds/dy, ds/dz if needed) at (xp(i),yp(i),zp(i)) :

The out_mode parameter defines the evaluation rule for extrapolation, i.e. for (xp(i),yp(i),zp(i)) not in [xmin,xmax]x[ymin,ymax]x[zmin,zmax] :

:”by_zero” an extrapolation by zero is done : :”by_nan” extrapolation by Nan : :”C0” the extrapolation is defined as follows :

s(x,y) = s(`proj`_(x,y)) `where`_ proj(x,y) is nearest point
                      of [x(1),x(nx)]x[y(1),y(ny)] from (x,y)

: :”periodic” s is extended by periodicity. :

Examples

// see the examples of the splin3d help page

See Also

• `splin3d`_ spline gridded 3d interpolation
• `bsplin3val`_ 3d spline arbitrary derivative evaluation function

History

Version Description 5.4.0 previously, imaginary part of input arguments were implicitly ignored. .. _splin3d: splin3d.html .. _bsplin3val: bsplin3val.html