如果A = np.array([0,1,2]),则np.nonzero(A)[0][0]返回1。但是,如果A = np.array([0,0,0]),则不起作用(在这种情况下,我希望答案3)。 而且,如果A很大,并且第一个非零在开始附近,这似乎效率很低。 相关问题:stackoverflow.com/questions/7632963/ 相关票务:/numpy/numpy/issues/2269 @ shx2嗯....
numpy.resize(arr, shape) 1. arr:要修改大小的输入数组 shape:返回数组的新形状 import numpy as np a = np.array([[1,2,3],[4,5,6]]) print(a.shape) print(a) b = np.resize(a,(3,2)) print(b) c=np.resize(a,(3,3)) print(c) (2, 3) [[1 2 3] [4 5 6]] [[1 2] ...
代码实现 importrandomimporttorchimportnumpyasnpdeffind_topk(a,k,axis=-1,largest=True,sorted=True):ifaxisisNone:axis_size=a.sizeelse:axis_size=a.shape[axis]assert1<=k<=axis_sizea=np.asanyarray(a)iflargest:index_array=np.argpartition(a,axis_size-k,axis=axis)topk_indices=np.take(index_a...
# Importing the NumPy library with an alias 'np'importnumpyasnp# Creating a NumPy array with specific data type (np.int32)x=np.array([[2,4,6],[6,8,10]],np.int32)# Printing the original arrayprint(x)# Accessing the fourth element (index 3) of the flattened array using the 'flat...
Python code to find first non-zero value in every column of a NumPy array # Import numpyimportnumpyasnp# Creating a numpy arrayarr=np.array([[1,1,0],[1,-1,0],[1,0,0],[1,1,0]])# Display original arrayprint("Original Array:\n",arr,"\n")# Defining a functiondeffun...
importnumpyasnp# create a 5x5 array with random valuesnums=np.random.rand(5,5)print("Original array elements:")print(nums)# find the indices of the second-largest value in each columnindices=np.argsort(nums,axis=0)[-2,:]# get the second-largest value in each column using the indices...
A memory-efficient approach is to find the row indexes of several values in a NumPy array, simply convert each row as linear index equivalents and then check if each element of an array is present in another by using the combination ofnp.in1d()andnp.where()methods. ...
数据集的图片(一个68 of的CSV文件)如下：现在根据深度学习书，自动编码器是一种神经网络，经过训练旨在...
We can use it to find the first index of a specific value in an array, as shown below. a=np.array([7,8,9,5,2,1,5,6,1])print(np.where(a==1)[0][0]) Output: 5 Use thenonzero()Function to Find the First Index of an Element in a NumPy Array ...
Given an array of integers,1 ≤ a[i] ≤ n(n = size of array), some elements appeartwiceand others appearonce. Find all the elements that appeartwicein this array. Could you do it without extra space and inO(n)O(n)runtime?