Numpy recarray.argmin () function | python

Record arrays allow you to access fields as elements of an array using arr.a and arr.b numpy.recarray.argmin () returns the indices of the min element of the array on a specific axis.

Syntax: numpy.recarray.argmin (axis = None, out = None)

Parameters:
axis: [int, optional] Along a specified axis like 0 or 1
out : [ndarray, optional] A location into which the result is stored.
 - & gt; If provided, it must have a shape that the inputs broadcast to.
 - & gt; If not provided or None, a freshly-allocated array is returned.

Returns: [ndarray of ints] Array of indices into the array with same shape as array.shape with the dimension along axis removed.

Code # 1:

# Python program explaining
# numpy.recarray.argmin () method

 
# import numy as a geek

import numpy as geek

 
# create an input array with two different fields

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 array of posts,
# 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.argmin methods to
# floating array of records along axis 1

out_arr = geek.recarray.argmin ( rec_arr.a, axis = 1 )

print ( "Output array along axis 1:" , out_arr) 

 
# application methods recarray.argmin to
# int array of records along axis 0

out_arr = geek.recarray.argmin (rec_arr.b, axis = 0 )

p rint ( "Output array along axis 0:" , out_arr) 

Output :

 Input array: [ [(5.0, 2) (3.0, 4) (6.0, 9)] [(9.0, 1) (5.0, 4) (-12.0, -7)]] Record array of float: [[5. 3. 6. ] [9. 5. -12.]] Record array of int: [[2 4 9] [1 4 -7]] Output array along axis 1: [1 2] Output array along axis 0: [1 0 1] 

Code # 2:

If we apply numpy.recarray.argmin () to the entire array of records then this will give Type error

# Python program explaining
# numpy.recarray.argmin () method

  
# import numy like a geek

import numpy as geek

  
# create an input array with two different fields

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 array:" , in_arr )

 
# convert it to an array of posts,
# using arr.view (np.recarray)

rec_arr = in_arr.view (geek.recarr ay)

 
# using recarray.argmin methods to write an array

out_arr = geek.recarray.argmin (rec_arr)

Exit:

TypeError: Cannot cast array data from dtype ((numpy.record, [('a', '& lt; f8 & # 8242;), (" b & # 8217 ;, " & lt; i8 ") ])) to dtype (" V16 ") according to the rule " safe "





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