numpy.polynomial.polyutils.getdomain

numpy.polynomial.polyutils.getdomain(x)

Return a domain suitable for given abscissae.

Find a domain suitable for a polynomial or Chebyshev series defined at the values supplied.

Parameters:

x : array_like

1-d array of abscissae whose domain will be determined.

Returns:

domain : ndarray

1-d array containing two values. If the inputs are complex, then the two returned points are the lower left and upper right corners of the smallest rectangle (aligned with the axes) in the complex plane containing the points x. If the inputs are real, then the two points are the ends of the smallest interval containing the points x.

See also

mapparms, mapdomain

Examples

>>> from numpy.polynomial import polyutils as pu
>>> points = np.arange(4)**2 - 5; points
array([-5, -4, -1,  4])
>>> pu.getdomain(points)
array([-5.,  4.])
>>> c = np.exp(complex(0,1)*np.pi*np.arange(12)/6) # unit circle
>>> pu.getdomain(c)
array([-1.-1.j,  1.+1.j])