关于unboundlocalerror:在赋值之前引用了局部变量'K‘

Question

我一直在尝试使用geostatistics library`，它的一个文件具有以下功能：

def krige( data, covfct, grid, method='simple', N=0, nugget=0 ):
    '''
    Krige an <Nx2> array of points representing a grid.

    Use either simple or ordinary kriging, some number N
    of neighboring points, and a nugget value.
    '''
    if method == 'simple':
        k = lambda d, c, u, N, nug: simple( d, c, u, N, nug ) 
    elif method == 'ordinary':
        k = lambda d, c, u, N, nug: ordinary( d, c, u, N, nug )
    print('method = ',method)
    M = len( grid )
    est, kstd = np.zeros(( M, 1 )), np.zeros(( M, 1 ))
    for i in range( M ):
        est[i], kstd[i] = k( data, covfct, grid[i], N, nugget )
    return est, kstd

在我看来，它包含两个可能的函数：simple和ordinary，通过lambda。lambda之后的u是否对应于est[i], kstd[i] = k( data, covfct, grid[i], N, nugget )中的grid[i]

我运行这里给出的示例代码，given here。例如,

import unittest
from geostatsmodels import kriging 
import numpy as np

data = np.array([[0,0,1],[1,0,3],[0,1,3],[1,1,4]])
hs = np.array([0.5,1.0,1.5,2.0])
bw = 0.5
u = [0.5,0.5]
N = 2
eps = 0.0001
kv = kriging.krige(data,kriging.spherical,hs,bw,u,N)

它给出了下面的错误信息，我不明白这是什么意思？

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Answer 1

if method == 'simple':
    k = lambda d, c, u, N, nug: simple( d, c, u, N, nug ) 
elif method == 'ordinary':
    k = lambda d, c, u, N, nug: ordinary( d, c, u, N, nug )

如果任何一个条件都不满足，k永远不会存在，所以它会给出UnboundLocalError。

kv = kriging.krige(data,kriging.spherical,hs,bw,u,N)这里你传递的是bw = 0.5，它既不是'simple'也不是'ordinary'。您需要将所需的参数传递给函数。