# naginterfaces.library.interp.dim2_​scat_​shep_​eval¶

naginterfaces.library.interp.dim2_scat_shep_eval(x, y, f, iq, rq, u, v)[source]

dim2_scat_shep_eval evaluates the two-dimensional interpolating function generated by dim2_scat_shep() and its first partial derivatives.

For full information please refer to the NAG Library document for e01sh

https://www.nag.com/numeric/nl/nagdoc_29/flhtml/e01/e01shf.html

Parameters
xfloat, array-like, shape

, , and must be the same values as were supplied in the preceding call to dim2_scat_shep().

yfloat, array-like, shape

, , and must be the same values as were supplied in the preceding call to dim2_scat_shep().

ffloat, array-like, shape

, , and must be the same values as were supplied in the preceding call to dim2_scat_shep().

iqint, array-like, shape

Must be unchanged from the value returned from a previous call to dim2_scat_shep().

rqfloat, array-like, shape

Must be unchanged from the value returned from a previous call to dim2_scat_shep().

ufloat, array-like, shape

The evaluation points , for .

vfloat, array-like, shape

The evaluation points , for .

Returns
qfloat, ndarray, shape

The values of the interpolant at , for . If any of these evaluation points lie outside the region of definition of the interpolant the corresponding entries in are set to an extrapolated approximation, and dim2_scat_shep_eval returns with = 3.

qxfloat, ndarray, shape

The values of the partial derivatives of the interpolant at , for . If any of these evaluation points lie outside the region of definition of the interpolant, the corresponding entries in and are set to extrapolated approximations to the partial derivatives, and dim2_scat_shep_eval returns with = 3.

qyfloat, ndarray, shape

The values of the partial derivatives of the interpolant at , for . If any of these evaluation points lie outside the region of definition of the interpolant, the corresponding entries in and are set to extrapolated approximations to the partial derivatives, and dim2_scat_shep_eval returns with = 3.

Raises
NagValueError
(errno )

On entry, is too small: .

(errno )

On entry, is too small: .

(errno )

On entry, .

Constraint: .

(errno )

On entry, .

Constraint: .

(errno )

On entry, values in appear to be invalid. Check that has not been corrupted between calls to dim2_scat_shep() and dim2_scat_shep_eval.

(errno )

On entry, values in appear to be invalid. Check that has not been corrupted between calls to dim2_scat_shep() and dim2_scat_shep_eval.

Warns
NagAlgorithmicWarning
(errno )

On entry, at least one evaluation point lies outside the region of definition of the interpolant. At such points the corresponding values in and contain extrapolated approximations. Points should be evaluated one by one to identify extrapolated values.

Notes

dim2_scat_shep_eval takes as input the interpolant of a set of scattered data points , for , as computed by dim2_scat_shep(), and evaluates the interpolant and its first partial derivatives at the set of points , for .

dim2_scat_shep_eval must only be called after a call to dim2_scat_shep().

This function is derived from the function QS2GRD described by Renka (1988).

References

Renka, R J, 1988, Algorithm 660: QSHEP2D: Quadratic Shepard method for bivariate interpolation of scattered data, ACM Trans. Math. Software (14), 149–150