Installing NumPy
If numpy is not yet installed, it can be installed via pip:
pip install numpy
Creating Arrays and Merging with numpy.concatenate
With numpy.concatenate, arrays can be combined along a specific axis. We start with small arrays and merge them row-wise and column-wise.
Example 1: Merging Simple Arrays Along the Row Axis (axis=0)
import numpy as np
# Zwei einfache Arrays erstellen
array1 = np.array([1, 2, 3])
array2 = np.array([4, 5, 6])
# Visualisierung der Arrays
print("Array 1:", array1)
print("Array 2:", array2)
# Mergen entlang der Zeilenachse (axis=0)
merged_array = np.concatenate((array1, array2), axis=0)
# Ausgabe des gemergten Arrays
print("Gemergtes Array entlang der Zeilenachse:", merged_array)
Output:
Array 1: [1 2 3]
Array 2: [4 5 6]
Gemergtes Array entlang der Zeilenachse: [1 2 3 4 5 6]
Here, two one-dimensional arrays are combined along the row axis into a single array.
Example 2: Merging Multidimensional Arrays Along the Row Axis (axis=0)
# Mehrdimensionale Arrays erstellen
array3 = np.array([[1, 2], [3, 4]])
array4 = np.array([[5, 6], [7, 8]])
# Visualisierung der Arrays
print("Array 3:\n", array3)
print("Array 4:\n", array4)
# Mergen entlang der Zeilenachse (axis=0)
merged_2d_array = np.concatenate((array3, array4), axis=0)
# Ausgabe des gemergten Arrays
print("Gemergtes Array entlang der Zeilenachse:\n", merged_2d_array)
Output:
Array 3:
[[1 2]
[3 4]]
Array 4:
[[5 6]
[7 8]]
Gemergtes Array entlang der Zeilenachse:
[[1 2]
[3 4]
[5 6]
[7 8]]
In this example, two 2x2 arrays are combined along the row axis, resulting in a 4x2 array.
Merging Arrays with numpy.hstack and numpy.vstack
The functions hstack and vstack allow simple merging of arrays horizontally (column-wise) or vertically (row-wise).
Example 3: Merging Arrays Horizontally with hstack
# Horizontales Mergen von 2x2 Arrays
array5 = np.array([[1, 2], [3, 4]])
array6 = np.array([[5, 6], [7, 8]])
# Visualisierung der Arrays
print("Array 5:\n", array5)
print("Array 6:\n", array6)
# Horizontales Mergen (spaltenweise)
hstacked_array = np.hstack((array5, array6))
# Ausgabe des gemergten Arrays
print("Horizontal gemergtes Array:\n", hstacked_array)
Output:
Array 5:
[[1 2]
[3 4]]
Array 6:
[[5 6]
[7 8]]
Horizontal gemergtes Array:
[[1 2 5 6]
[3 4 7 8]]
Here, two arrays are combined column-wise, resulting in an array with four columns.
Example 4: Merging Arrays Vertically with vstack
# Vertikales Mergen von 1x4 Arrays
array7 = np.array([1, 2, 3, 4])
array8 = np.array([5, 6, 7, 8])
# Visualisierung der Arrays
print("Array 7:", array7)
print("Array 8:", array8)
# Vertikales Mergen (zeilenweise)
vstacked_array = np.vstack((array7, array8))
# Ausgabe des gemergten Arrays
print("Vertikal gemergtes Array:\n", vstacked_array)
Output:
Array 7: [1 2 3 4]
Array 8: [5 6 7 8]
Vertikal gemergtes Array:
[[1 2 3 4]
[5 6 7 8]]
In this example, two one-dimensional arrays are combined row-wise, resulting in a 2x4 array.
Merging Arrays with numpy.stack
With numpy.stack, arrays can be combined along a new axis. This adds an additional dimension, which is particularly useful for multidimensional data.
Example 5: Merging Arrays Along a New Axis
# Mehrdimensionale Arrays erstellen
array9 = np.array([[1, 2], [3, 4]])
array10 = np.array([[5, 6], [7, 8]])
# Visualisierung der Arrays
print("Array 9:\n", array9)
print("Array 10:\n", array10)
# Mergen entlang einer neuen Achse
stacked_array = np.stack((array9, array10), axis=0)
# Ausgabe des gemergten Arrays
print("Gemergtes Array entlang einer neuen Achse:\n", stacked_array)
Output:
Array 9:
[[1 2]
[3 4]]
Array 10:
[[5 6]
[7 8]]
Gemergtes Array entlang einer neuen Achse:
[[[1 2]
[3 4]]
[[5 6]
[7 8]]]
In this example, an additional dimension (axis 0) is added, combining the arrays in a higher dimension.