naginterfaces.library.fit.dim2_spline_evalm¶
- naginterfaces.library.fit.dim2_spline_evalm(x, y, lamda, mu, c)[source]¶
dim2_spline_evalm
calculates values of a bicubic spline from its B-spline representation. The spline is evaluated at all points on a rectangular grid.For full information please refer to the NAG Library document for e02df
https://support.nag.com/numeric/nl/nagdoc_30.2/flhtml/e02/e02dff.html
- Parameters
- xfloat, array-like, shape
and must contain , for , and , for , respectively. These are the and coordinates that define the rectangular grid of points at which values of the spline are required.
- yfloat, array-like, shape
and must contain , for , and , for , respectively. These are the and coordinates that define the rectangular grid of points at which values of the spline are required.
- lamdafloat, array-like, shape
and must contain the complete sets of knots and associated with the and variables respectively.
- mufloat, array-like, shape
and must contain the complete sets of knots and associated with the and variables respectively.
- cfloat, array-like, shape
must contain the coefficient described in Notes, for , for .
- Returns
- fffloat, ndarray, shape
contains the value of the spline at the point , for , for .
- Raises
- NagValueError
- (errno )
On entry, .
Constraint: .
- (errno )
On entry, .
Constraint: .
- (errno )
On entry, .
Constraint: .
- (errno )
On entry, .
Constraint: .
- (errno )
On entry, the knots in are not in nondecreasing order.
- (errno )
On entry, the knots in are not in nondecreasing order.
- (errno )
On entry, is violated.
- (errno )
On entry, is violated.
- Notes
In the NAG Library the traditional C interface for this routine uses a different algorithmic base. Please contact NAG if you have any questions about compatibility.
dim2_spline_evalm
calculates values of the bicubic spline on a rectangular grid of points in the - plane, from its augmented knot sets and and from the coefficients , for , for , in its B-spline representationHere and denote normalized cubic B-splines, the former defined on the knots to and the latter on the knots to .
The points in the grid are defined by coordinates , for , along the axis, and coordinates , for , along the axis.
This function may be used to calculate values of a bicubic spline given in the form produced by
interp.dim2_spline_grid
,dim2_spline_panel()
,dim2_spline_grid()
anddim2_spline_sctr()
. It is derived from the function B2VRE in Anthony et al. (1982).
- References
Anthony, G T, Cox, M G and Hayes, J G, 1982, DASL – Data Approximation Subroutine Library, National Physical Laboratory
Cox, M G, 1978, The numerical evaluation of a spline from its B-spline representation, J. Inst. Math. Appl. (21), 135–143