python - 从 numpy 数组 float32 到 numpy 数组 float64 的转换

Question

我正在尝试用 Python 实现随机森林。运行代码时我收到此错误。尽管我已经使用以下方法从 float32 转换为 float64:

x_arr = np.array(train_df, dtype='float64')

Traceback(most recent call last):
  File "C:\Python27\randomforest.py", line 67, in <module>     
    forest=forest.fit(x_array[0::,1::],x_array[0::,0])
  File "C:\Python27\lib\site-packages\sklearn\ensemble\forest.py", line 212, in fit
    X = check_array(X, dtype=DTYPE, accept_sparse="csc")   
  File "C:\Python27\lib\site-packages\sklearn\utils\validation.py", line 398, in check_array
    _assert_all_finite(array)
  File "C:\Python27\lib\site-packages\sklearn\utils\validation.py", line 54, in _assert_all_finite
    " or a value too large for %r." % X.dtype)
ValueError: Input contains NaN, infinity or a value too large for dtype('float32').  

请问有人可以帮忙吗？

Answer 1

问题不在于您未能设置 float64 dtype。错误消息显示:

Input contains NaN, infinity or a value too large for dtype('float32').

因此，请先尝试检查这些条件:

assert not np.any(np.isnan(x_arr))
assert np.all(np.isfinite(x_arr))
assert np.all(x_arr <= finfo('float32').max)
assert np.all(x_arr >= finfo('float32').min)