时间:2021-05-22
如下所示:
def append(arr, values, axis=None): """ Append values to the end of an array. Parameters ---------- arr : array_like Values are appended to a copy of this array. values : array_like These values are appended to a copy of `arr`. It must be of the correct shape (the same shape as `arr`, excluding `axis`). If `axis` is not specified, `values` can be any shape and will be flattened before use. axis : int, optional The axis along which `values` are appended. If `axis` is not given, both `arr` and `values` are flattened before use. Returns ------- append : ndarray A copy of `arr` with `values` appended to `axis`. Note that `append` does not occur in-place: a new array is allocated and filled. If `axis` is None, `out` is a flattened array.numpy.append(arr, values, axis=None):
简答来说,就是arr和values会重新组合成一个新的数组,做为返回值。而axis是一个可选的值
当axis无定义时,是横向加成,返回总是为一维数组!
Examples -------- >>> np.append([1, 2, 3], [[4, 5, 6], [7, 8, 9]]) array([1, 2, 3, 4, 5, 6, 7, 8, 9])当axis有定义的时候,分别为0和1的时候。(注意加载的时候,数组要设置好,行数或者列数要相同。不然会有error:all the input array dimensions except for the concatenation axis must match exactly)
当axis为0时,数组是加在下面(列数要相同):
import numpy as npaa= np.zeros((1,8))bb=np.ones((3,8))c = np.append(aa,bb,axis = 0)print(c)[[ 0. 0. 0. 0. 0. 0. 0. 0.] [ 1. 1. 1. 1. 1. 1. 1. 1.] [ 1. 1. 1. 1. 1. 1. 1. 1.] [ 1. 1. 1. 1. 1. 1. 1. 1.]]当axis为1时,数组是加在右边(行数要相同):
import numpy as npaa= np.zeros((3,8))bb=np.ones((3,1))c = np.append(aa,bb,axis = 1)print(c)[[ 0. 0. 0. 0. 0. 0. 0. 0. 1.] [ 0. 0. 0. 0. 0. 0. 0. 0. 1.] [ 0. 0. 0. 0. 0. 0. 0. 0. 1.]]以上这篇对numpy.append()里的axis的用法详解就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持。
声明:本页内容来源网络,仅供用户参考;我单位不保证亦不表示资料全面及准确无误,也不保证亦不表示这些资料为最新信息,如因任何原因,本网内容或者用户因倚赖本网内容造成任何损失或损害,我单位将不会负任何法律责任。如涉及版权问题,请提交至online#300.cn邮箱联系删除。
numpy的delete是可以删除数组的整行和整列的,下面简单介绍和举例说明delete函数用法:numpy.delete(arr,obj,axis=None)
合并numpy中numpy中可以通过concatenate,指定参数axis=0或者axis=1,在纵轴和横轴上合并两个数组。importnumpyasnpim
用法:mean(matrix,axis=0)其中matrix为一个矩阵,axis为参数以m*n矩阵举例:axis不设置值,对m*n个数求均值,返回一个实数axi
基础介绍:numpy.deletenumpy.delete(arr,obj,axis=None)[source]Returnanewarraywithsub-a
直接上代码了x=np.empty(shape=[0,4],int)x=np.append(x,[[1,2,3,4]],axis=0)x=np.append(x,