Module « scipy.interpolate »

Classe « LSQSphereBivariateSpline »

Informations générales

Héritage

builtins.object
    _BivariateSplineBase
        SphereBivariateSpline
            LSQSphereBivariateSpline

Définition

class LSQSphereBivariateSpline(SphereBivariateSpline):

Description _{[extrait de LSQSphereBivariateSpline.__doc__]}

    Weighted least-squares bivariate spline approximation in spherical
    coordinates.

    Determines a smoothing bicubic spline according to a given
    set of knots in the `theta` and `phi` directions.

    .. versionadded:: 0.11.0

    Parameters
    ----------
    theta, phi, r : array_like
        1-D sequences of data points (order is not important). Coordinates
        must be given in radians. Theta must lie within the interval
        ``[0, pi]``, and phi must lie within the interval ``[0, 2pi]``.
    tt, tp : array_like
        Strictly ordered 1-D sequences of knots coordinates.
        Coordinates must satisfy ``0 < tt[i] < pi``, ``0 < tp[i] < 2*pi``.
    w : array_like, optional
        Positive 1-D sequence of weights, of the same length as `theta`, `phi`
        and `r`.
    eps : float, optional
        A threshold for determining the effective rank of an over-determined
        linear system of equations. `eps` should have a value within the
        open interval ``(0, 1)``, the default is 1e-16.

    See Also
    --------
    BivariateSpline :
        a base class for bivariate splines.
    UnivariateSpline :
        a smooth univariate spline to fit a given set of data points.
    SmoothBivariateSpline :
        a smoothing bivariate spline through the given points
    LSQBivariateSpline :
        a bivariate spline using weighted least-squares fitting
    RectSphereBivariateSpline :
        a bivariate spline over a rectangular mesh on a sphere
    SmoothSphereBivariateSpline :
        a smoothing bivariate spline in spherical coordinates
    RectBivariateSpline :
        a bivariate spline over a rectangular mesh.
    bisplrep :
        a function to find a bivariate B-spline representation of a surface
    bisplev :
        a function to evaluate a bivariate B-spline and its derivatives

    Notes
    -----
    For more information, see the FITPACK_ site about this function.

    .. _FITPACK: http://www.netlib.org/dierckx/sphere.f

    Examples
    --------
    Suppose we have global data on a coarse grid (the input data does not
    have to be on a grid):

    >>> from scipy.interpolate import LSQSphereBivariateSpline
    >>> import matplotlib.pyplot as plt

    >>> theta = np.linspace(0, np.pi, num=7)
    >>> phi = np.linspace(0, 2*np.pi, num=9)
    >>> data = np.empty((theta.shape[0], phi.shape[0]))
    >>> data[:,0], data[0,:], data[-1,:] = 0., 0., 0.
    >>> data[1:-1,1], data[1:-1,-1] = 1., 1.
    >>> data[1,1:-1], data[-2,1:-1] = 1., 1.
    >>> data[2:-2,2], data[2:-2,-2] = 2., 2.
    >>> data[2,2:-2], data[-3,2:-2] = 2., 2.
    >>> data[3,3:-2] = 3.
    >>> data = np.roll(data, 4, 1)

    We need to set up the interpolator object. Here, we must also specify the
    coordinates of the knots to use.

    >>> lats, lons = np.meshgrid(theta, phi)
    >>> knotst, knotsp = theta.copy(), phi.copy()
    >>> knotst[0] += .0001
    >>> knotst[-1] -= .0001
    >>> knotsp[0] += .0001
    >>> knotsp[-1] -= .0001
    >>> lut = LSQSphereBivariateSpline(lats.ravel(), lons.ravel(),
    ...                                data.T.ravel(), knotst, knotsp)

    As a first test, we'll see what the algorithm returns when run on the
    input coordinates

    >>> data_orig = lut(theta, phi)

    Finally we interpolate the data to a finer grid

    >>> fine_lats = np.linspace(0., np.pi, 70)
    >>> fine_lons = np.linspace(0., 2*np.pi, 90)
    >>> data_lsq = lut(fine_lats, fine_lons)

    >>> fig = plt.figure()
    >>> ax1 = fig.add_subplot(131)
    >>> ax1.imshow(data, interpolation='nearest')
    >>> ax2 = fig.add_subplot(132)
    >>> ax2.imshow(data_orig, interpolation='nearest')
    >>> ax3 = fig.add_subplot(133)
    >>> ax3.imshow(data_lsq, interpolation='nearest')
    >>> plt.show()

    

Constructeur(s)

Signature du constructeur	Description
__init__(self, theta, phi, r, tt, tp, w=None, eps=1e-16)

Liste des opérateurs

Opérateurs hérités de la classe object

__eq__, __ge__, __gt__, __le__, __lt__, __ne__

Méthodes héritées de la classe SphereBivariateSpline

__init_subclass__, __subclasshook__, ev

Méthodes héritées de la classe _BivariateSplineBase

get_coeffs, get_knots, get_residual

Méthodes héritées de la classe object

__delattr__, __dir__, __format__, __getattribute__, __hash__, __reduce__, __reduce_ex__, __repr__, __setattr__, __sizeof__, __str__