Python Numpy recarray.repeat()用法及代码示例

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)]，其中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(例如，arr['a'] and arr['b']。记录数组允许使用以下方式将字段作为数组的成员进行访问arr.a and arr.b。

numpy.recarray.repeat()函数用于重复记录数组的元素。

用法： numpy.recarray.repeat(repeats, axis=None)

参数：
repeats:[int或整数数组]每个元素的重复次数。
axis :[int或None]沿其重复值的轴。如果为None，则在重复之前将阵列弄平。

Return :[ndarray]输出数组，其形状与记录数组相同，但沿给定轴除外。

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)

输出：

Input array: [[( 5., 2) ( 3., -4) ( 6., 9)]
[( 9., 1) ( 5., 4) (-12., -7)]]
Record array of float: [[ 5. 3. 6.]
[ 9. 5. -12.]]
Record array of int: [[ 2 -4 9]
[ 1 4 -7]]

Output repeated float array along axis 1: [[ 5. 5. 5. 3. 3. 3. 6. 6. 6.]
[ 9. 9. 9. 5. 5. 5. -12. -12. -12.]]
Output repeated float array along default axis: [ 5. 5. 3. 3. 6. 6. 9. 9. 5. 5. -12. -12.]
Output repeated int array along axis 0: [[ 2 -4 9]
[ 2 -4 9]
[ 1 4 -7]
[ 1 4 -7]]
Output repeated int array along default axis: [ 2 2 -4 -4 9 9 1 1 4 4 -7 -7]

代码2：

我们正在申请numpy.recarray.repeat()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)

输出：

Input record array: [[( 5., 2) ( 3., 4) ( 6., -7)]
[( 9., 1) ( 6., 4) (-2., -7)]]

Output repeated record array:
[( 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)]

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注：本文由纯净天空筛选整理自jana_sayantan大神的英文原创作品 Numpy recarray.repeat() function | Python。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。