Numpy recarray.repeat()函数| Python
原文:https://www . geeksforgeeks . org/numpy-recarray-repeat-function-python/
在 numpy 中，数组可能具有包含字段的数据类型，类似于电子表格中的列。一个例子是[(a, int), (b, float)]，数组中的每个条目都是一对(int，float)。通常，这些属性是使用字典查找来访问的，例如arr['a'] and arr['b']。使用arr.a and arr.b，记录数组允许字段作为数组的成员被访问。
numpy.recarray.repeat() 功能用于重复记录数组的元素。
语法:
numpy.recarray.repeat(repeats, axis=None)参数: 重复:【int 或 int 数组】每个元素的重复次数。 轴:【int 或 None】沿其重复值的轴。如果为“无”，则在重复之前先展平数组。
返回:【n 数组】输出数组，除了沿给定轴外，与记录数组形状相同。
代码#1 :
# Python program explaining
# numpy.recarray.repeat() method
# importing numpy as geek
import numpy as geek
# creating input array with 2 different field
in_arr = geek.array([[(5.0, 2), (3.0, -4), (6.0, 9)],
[(9.0, 1), (5.0, 4), (-12.0, -7)]],
dtype =[('a', float), ('b', int)])
print ("Input array : ", in_arr)
# convert it to a record array,
# using arr.view(np.recarray)
rec_arr = in_arr.view(geek.recarray)
print("Record array of float: ", rec_arr.a)
print("Record array of int: ", rec_arr.b)
# applying recarray.repeat methods
# to float record array along axis 1
out_arr = rec_arr.a.repeat(3, axis = 1)
print ("Output repeated float array along axis 1 : ", out_arr)
# applying recarray.repeat methods
# to float record array along default axis
out_arr = rec_arr.a.repeat(2)
print ("Output repeated float array along default axis : ", out_arr)
# applying recarray.repeat methods
# to int record array along axis 0
out_arr = rec_arr.b.repeat(2, axis = 0)
print ("Output repeated int array along axis 0 : ", out_arr)
# applying recarray.repeat methods
# to int record array along default
out_arr = rec_arr.b.repeat(2)
print ("Output repeated int array along default axis : ", out_arr)
Output:
输入数组:[[( 5。, 2) ( 3., -4) ( 6.，9)】 【(9。, 1) ( 5., 4) (-12.，-7)] 记录数组的 float: [[ 5。3.6.】 【9。5.-12.]] 记录 int 的数组:[[ 2 -4 9] [ 1 4 -7]]
沿轴 1 输出重复的浮点数组:[[ 5。5.5.3.3.3.6.6.6.】 【9。9.9.5.5.5.-12.-12.-12.]] 沿默认轴输出重复的浮点数组:[5]。5.3.3.6.6.9.9.5.5.-12.-12.】 沿 0 轴输出重复 int 数组:【[2-4 9]】 【2-4 9】 【1 4-7】 【1 4-7】】 沿默认轴输出重复 int 数组:【2 2-4-4 9 1 4-7-7】
代码#2 :
我们将numpy.recarray.repeat()应用于整个记录数组。
# Python program explaining
# numpy.recarray.repeat() method
# importing numpy as geek
import numpy as geek
# creating input array with 2 different field
in_arr = geek.array([[(5.0, 2), (3.0, 4), (6.0, -7)],
[(9.0, 1), (6.0, 4), (-2.0, -7)]],
dtype =[('a', float), ('b', int)])
print ("Input record array : ", in_arr)
# convert it to a record array,
# using arr.view(np.recarray)
rec_arr = in_arr.view(geek.recarray)
# applying recarray.repeat methods to record array
out_arr = rec_arr.repeat(3)
print ("Output repeated record array : ", out_arr)
Output:
输入记录数组:[[( 5。, 2) ( 3., 4) ( 6.，-7)] [( 9。, 1) ( 6., 4) (-2., -7)]]
输出重复记录数组: [( 5。, 2) ( 5., 2) ( 5., 2) ( 3., 4) ( 3., 4) ( 3., 4) ( 6.，-7) ( 6。, -7) ( 6., -7) ( 9., 1) ( 9., 1) ( 9., 1) ( 6., 4) ( 6.，4) ( 6。, 4) (-2., -7) (-2., -7) (-2., -7)]
