Python在2D网格上插值点值

Question

我有一个常规的2D X,Y和Z数组,我有一个点X0和Y0,我想知道我的网格上的点(X0,Y0)中的Z0值.

我发现scipy有插值模块,但据我所知它插入1D/2D数组并返回1D/2D数组,但是没有方法只能在一个点返回一个值.

例如:

#My grid data
X = [ [X11, X12, X13, ..., X1N], 
      [X21, X22, X23, ..., X2N],
          ....
      [XN1, XN2, XN3, ..., XNN]

Y = [ [Y11, Y12, Y13, ..., Y1N], 
      [Y21, Y22, Y23, ..., Y2N],
          ....
      [YN1, YN2, YN3, ..., YNN] ]

Z = [ [Z11, Z12, Z13, ..., Z1N], 
      [Z21, Z22, Z23, ..., Z2N],
          ....
      [ZN1, ZN2, ZN3, ..., ZNN] ]

#Point at which I want to know the value of the Z
X0, Y0 = ..., ...

#Now I want to call any function that'll return the value at point (X0, Y0), Z0 is float value, not array
Z0 = interpolation(X, Y, Z, X0, Y0)

据我所知,类似的函数是scipy.interpolate.interpn,但它只适用于1D数组,当我想处理2D数据时发出错误

Answer 1

• 你也可以使用griddata:

  points = np.array( (X.flatten(), Y.flatten()) ).T
  values = Z.flatten()
  
  from scipy.interpolate import griddata
  Z0 = griddata( points, values, (X0,Y0) )
  

• X0和Y0可以是数组甚至是网格.

• 你也可以用method =选择插值
• 也许你可以找到一种方法来获得flatten(),但它应该工作.

(https://docs.scipy.org/doc/scipy/reference/tutorial/interpolate.html)