# scipy.interpolate.bisplev

scipy.interpolate.bisplev(x, y, tck, dx=0, dy=0)

  Evaluate a bivariate B-spline and its derivatives.

  Return a rank-2 array of spline function values (or spline derivative values) at points given by the cross-product of the rank-1 arrays x and y. In special cases, return an array or just a float if either x or y or both are floats. Based on BISPEV and PARDER from FITPACK.

  Parameters:
    x, y ndarray

      Rank-1 arrays specifying the domain over which to evaluate the spline or its derivative.

    tck tuple

      A sequence of length 5 returned by `bisplrep` containing the knot locations, the coefficients, and the degree of the spline: [tx, ty, c, kx, ky].

    dx, dy int, optional

      The orders of the partial derivatives in x and y respectively.

  Returns:
    vals ndarray

      The B-spline or its derivative evaluated over the set formed by the cross-product of x and y.

  See also

  `splprep`, `splrep`, `splint`, `sproot`, `splev`
  `UnivariateSpline`, `BivariateSpline`

  Notes

  See `bisplrep` to generate the tck representation.

  References

  [1]

  Dierckx P. : An algorithm for surface fitting with spline functions Ima J. Numer. Anal. 1 (1981) 267-283.

  [2]

  Dierckx P. : An algorithm for surface fitting with spline functions report tw50, Dept. Computer Science,K.U.Leuven, 1980.

  [3]

  Dierckx P. : Curve and surface fitting with splines, Monographs on Numerical Analysis, Oxford University Press, 1993.

  Examples

  Examples are given in the tutorial.