__init__(self, x, y, z, bbox = ([ None ] * 4), kx = 3, ky = 3, s = 0)
Input:
x,y - 1-d sequences of coordinates in strictly ascending order
z - 2-d array of data with shape (x.size,y.size)
Optional input:
bbox - 4-sequence specifying the boundary of
the rectangular approximation domain.
By default, bbox=[min(x,tx),max(x,tx),
min(y,ty),max(y,ty)]
kx,ky=3,3 - degrees of the bivariate spline.
s - positive smoothing factor defined for
estimation condition:
sum((w[i]*(z[i]-s(x[i],y[i])))**2,axis=0) <= s
Default s=0 which is for interpolation
