Python_N-005. 10 basic attributes in array (2)

N-005_10_basic_attribute_in_array(2).py

0.00MB

 

No.	Commend	Description	Example
1	indexing	Accessing individual elements using indices.	arr[0, 1]   # in the first row, second column
2	slicing	Accessing a range of elements using : operator	arr[0:2, 1:3]   #  from rows 0-1 and columns 1-2                      # arr[ a : n ]   from a to (n-1)
3	copy()	Creates a copy of the array	arr_copy = arr.copy()
4	reshape()	Returns an array with a new shape	arr_reshaped = arr.reshape(1, 9)
5	newaxis	Adds a new axis to the array	arr_newaxis = arr[  np.newaxis, :, :]
6	concatenate	Joins a sequence of arrays along an existing axis	np.concatenate(  (arr1, arr2), axis=0)
7	vstack()	Stacks arrays insequence vertically (row-wise) ==> always along axis 0	#  np.vstack((arr1, arr2))
8	hstack()	Stacks arrays in sequence horizontally (column-wise) ==> always along axis 1	np.hstack((arr1, arr2))
9	split()	Splits an array into multiple sub-arrays	np.split(arr, 3) # Splits into 3 equal-sized sub-arrays
10	vsplit()	Splits an array into multiple sub-arrays vertically (row-wise)	np.vsplit(arr, 3) # Splits into 3 sub-arrays along rows
11	hsplit()	Splits an array into multiple sub-arrays horizontally (column-wise)	np.hsplit(arr, 3) # Splits into 3 sub-arrays along columns

 

Key differences between concatenate and vstack/hstack

Function	Description	Axis of Operation	Example Use Case
concatenate	Joins arrays along an existing axis	Can be specified (default is 0)	General use for combining arrays
vstack	Stacks arrays vertically	Always along axis 0	Adding rows to a 2D array
hstack	Stacks arrays horizontally	Always along axis 1	Adding columns to a 2D array

To summarize:

• concatenate is more flexible since you can specify the axis along which to concatenate.
• vstack / hstack are more specific for stacking arrays vertically or horizontally, respectively, and can be easier to use for those specific tasks.
•  

Key Differences between split and vsplit / hsplit

Function	Description	Axis of Operation	Example Use Case
split	Splits array into sub-arrays	Can specify axis (default is 0)	General use for splitting arrays
vsplit	Splits array vertically	Always splits along axis 0 (rows)	Splitting an array into row-wise sub-arrays
hsplit	Splits array horizontally	Always splits along axis 1 (columns)	Splitting an array into column-wise sub-arrays

To summarize:

• split is more flexible as you can specify the axis along which to split.
• vsplit and hsplit are specifically for splitting arrays vertically or horizontally, respectively, and can be easier to use for those specific tasks.