[英]error when plotting log'd array in matplotlib/scipy/numpy
我有兩個數組,我記錄了它們的日志。 當我這樣做並嘗試繪制其散點圖時,出現此錯誤:
File "/Library/Python/2.6/site-packages/matplotlib-1.0.svn_r7892-py2.6-macosx-10.6-universal.egg/matplotlib/pyplot.py", line 2192, in scatter
ret = ax.scatter(x, y, s, c, marker, cmap, norm, vmin, vmax, alpha, linewidths, faceted, verts, **kwargs)
File "/Library/Python/2.6/site-packages/matplotlib-1.0.svn_r7892-py2.6-macosx-10.6-universal.egg/matplotlib/axes.py", line 5384, in scatter
self.add_collection(collection)
File "/Library/Python/2.6/site-packages/matplotlib-1.0.svn_r7892-py2.6-macosx-10.6-universal.egg/matplotlib/axes.py", line 1391, in add_collection
self.update_datalim(collection.get_datalim(self.transData))
File "/Library/Python/2.6/site-packages/matplotlib-1.0.svn_r7892-py2.6-macosx-10.6-universal.egg/matplotlib/collections.py", line 153, in get_datalim
offsets = transOffset.transform_non_affine(offsets)
File "/Library/Python/2.6/site-packages/matplotlib-1.0.svn_r7892-py2.6-macosx-10.6-universal.egg/matplotlib/transforms.py", line 1924, in transform_non_affine
self._a.transform(points))
File "/Library/Python/2.6/site-packages/matplotlib-1.0.svn_r7892-py2.6-macosx-10.6-universal.egg/matplotlib/transforms.py", line 1420, in transform
return affine_transform(points, mtx)
ValueError: Invalid vertices array.
代碼很簡單:
myarray_x = log(my_array[:, 0])
myarray_y = log(my_array[:, 1])
plt.scatter(myarray_x, myarray_y)
知道是什么原因造成的嗎? 謝謝。
我遇到了最近解決的相同問題:
對我來說,問題是我的X和Y(numpy)數組由128位浮點數組成。
在這種情況下,解決方案是將數組重鑄為較低精度的浮點數,即
array = numpy.float64(array)
希望這會有所幫助:〜)
新答案:
從源頭看,如果傳遞給affine_transform的points數組的尺寸錯誤或為空,則會引發此錯誤。 以下是相關行:
if (!vertices ||
(PyArray_NDIM(vertices) == 2 && PyArray_DIM(vertices, 1) != 2) ||
(PyArray_NDIM(vertices) == 1 && PyArray_DIM(vertices, 0) != 2))
throw Py::ValueError("Invalid vertices array.");
在繼續進行之前,請看一下myarray_x和myarray_y數組的尺寸。
舊答案 :
我最大的猜想是,您正在取值<= 0的對數。這將在數組中給出nan或-infs(在等於0的情況下),當然它無法繪制。
(wiso是正確的-這些要點將被忽略)
這對我來說成功運行了
>>> from numpy import log, array
>>> import matplotlib.pyplot as plt
>>> my_array = array([[1.0, 2.0], [3.0, 4.0], [5.0, 6.0]])
>>> my_array
array([[ 1., 2.],
[ 3., 4.],
[ 5., 6.]])
>>> myarray_x = log(my_array[:, 0])
>>> myarray_y = log(my_array[:, 1])
>>> plt.scatter(myarray_x, myarray_y)
<matplotlib.collections.CircleCollection object at 0x030C7A10>
>>> plt.show()
所以問題可能出在您未向我們展示的內容上。 您能否提供與運行時一樣的完整示例代碼,以便我們重現您的問題?
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.