a = np.array([0.5 , 0.505, 0.51 , 0.515, 0.52 , 0.525, 0.53 , 0.535, 0.54 ,
0.545, 0.55 , 0.555, 0.56 , 0.565, 0.57 , 0.575, 0.58 , 0.585,
0.59 , 0.595])
b = np.array([ 49.62358846, 50.21487603, 53.03564434, 51.68435625,
53.25301205, 54.04002965, 54.97835498, 52.83363803,
59.1954023 , 59.82532751, 60.33057851, 56.16438356,
53.33333333, 72.22222222, 51.72413793, 41.66666667,
33.33333333, 44.44444444, 25. , 100. ])
np.polyfit(a, b, 1)
有时这是可行的,有时是可行的,并抛出下面的错误。有人能重复这句话吗?或者有人知道发生了什么吗?对于像这样好的数据,它永远不会抛出错误。
*LinAlgError Traceback (most recent call last)
<ipython-input-274-d8db33e4c692> in <module>
----> 1 np.polyfit(a, b, 1)
<__array_function__ internals> in polyfit(*args, **kwargs)
C:\ProgramData\other\lib\site-packages\numpy\lib\polynomial.py in polyfit(x, y, deg, rcond, full, w, cov)
627 scale = NX.sqrt((lhs*lhs).sum(axis=0))
628 lhs /= scale
--> 629 c, resids, rank, s = lstsq(lhs, rhs, rcond)
630 c = (c.T/scale).T # broadcast scale coefficients
631
<__array_function__ internals> in lstsq(*args, **kwargs)
C:\ProgramData\other\lib\site-packages\numpy\linalg\linalg.py in lstsq(a, b, rcond)
2304 # lapack can't handle n_rhs = 0 - so allocate the array one larger in that axis
2305 b = zeros(b.shape[:-2] + (m, n_rhs + 1), dtype=b.dtype)
-> 2306 x, resids, rank, s = gufunc(a, b, rcond, signature=signature, extobj=extobj)
2307 if m == 0:
2308 x[...] = 0
C:\ProgramData\other\lib\site-packages\numpy\linalg\linalg.py in _raise_linalgerror_lstsq(err, flag)
98
99 def _raise_linalgerror_lstsq(err, flag):
--> 100 raise LinAlgError("SVD did not converge in Linear Least Squares")
101
102 def get_linalg_error_extobj(callback):
LinAlgError: SVD did not converge in Linear Least Squares*
发布于 2020-09-30 14:59:01
我在这里发现了完全相同的问题:numpy.linalg.LinAlgError: SVD did not converge in Linear Least Squares on first run only
从那时起,在做数据科学学习课程时,又遇到了同样的问题。如果你再次运行这段完全相同的代码,它将会工作…没有收敛是有正当理由的,比如NaNs等--但正如疯狂科学家指出的那样,SVD似乎存在一个真正的问题。
https://stackoverflow.com/questions/64111921
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