Stack those horizontally with np.hstack and flatten with np.ravel -

np.hstack(( a,b,c )).ravel()
Answer from Divakar on Stack Overflow
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NumPy
numpy.org › doc › stable › reference › generated › numpy.concatenate.html
numpy.concatenate — NumPy v2.5 Manual
Join a sequence of arrays along an existing axis. New in version 2.0: numpy.concat added as a shorthand for numpy.concatenate.
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Stack Overflow
stackoverflow.com › questions › 42488989 › python-concatenate-3-arrays
numpy - Python: Concatenate 3 arrays - Stack Overflow
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Stack those horizontally with np.hstack and flatten with np.ravel -

np.hstack(( a,b,c )).ravel()
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d=np.concatenate((a, b,c), axis=None)

The None parameter ensures that the arrays are flattened before concatenation (the gluing of arrays).

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How do i combine multiple numpy arrays into one?
np.stack(), np.vstack(), np.hstack(), np.dstack(), np.concatenate(), np.column_stack(), np.row_stack(). One of those might work for your case. Just check out the examples for what might be analogous to your problem. Probably a horizontal stack if this is a 1D array (error message). Check out the left menu: https://numpy.org/doc/stable/reference/generated/numpy.stack.html#numpy.stack More on reddit.com
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How do I merge separate RGB bands composed of numpy arrays?
Just use python's zip function. You can pass all the three lists - like so: RGB_arr = zip(R,G,B). More on reddit.com
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NumPy
numpy.org › devdocs › reference › generated › numpy.concatenate.html
numpy.concatenate — NumPy v2.6.dev0 Manual
Join a sequence of arrays along an existing axis. Added in version 2.0: numpy.concat added as a shorthand for numpy.concatenate.
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Vultr Docs
docs.vultr.com › python › third party › numpy › concatenate()
Python Numpy concatenate() - Join Arrays Together
November 7, 2024 - The example concatenates array1, ... of all three arrays. The concatenate() function in Numpy is a robust tool for array manipulation, allowing arrays to be joined efficiently along different dimensions....
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NumPy
numpy.org › doc › 1.23 › reference › generated › numpy.concatenate.html
numpy.concatenate — NumPy v1.23 Manual
The axis along which the arrays will be joined. If axis is None, arrays are flattened before use. Default is 0. ... If provided, the destination to place the result. The shape must be correct, matching that of what concatenate would have returned if no out argument were specified.
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NumPy
numpy.org › doc › 1.18 › reference › generated › numpy.concatenate.html
numpy.concatenate — NumPy v1.18 Manual
May 24, 2020 - Concatenate function that preserves input masks. ... Split an array into multiple sub-arrays of equal or near-equal size. ... Split array into a list of multiple sub-arrays of equal size. ... Split array into multiple sub-arrays along the 3rd axis (depth).
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w3resource
w3resource.com › python-exercises › numpy › python-numpy-exercise-165.php
Python NumPy: Merge three given NumPy arrays of same shape - w3resource
The above three statements create ... result = np.concatenate((arr1, arr2, arr3), axis=-1): This line concatenate the three arrays along the last axis (axis=-1) using the np.concatenate() function....
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DataCamp
datacamp.com › doc › numpy › concatenate
NumPy concatenate()
The NumPy `concatenate()` function is an array operation used to join two or more arrays along a specified axis.
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W3Schools
w3schools.com › python › numpy › numpy_array_join.asp
NumPy Joining Array
We pass a sequence of arrays that we want to join to the concatenate() function, along with the axis. If axis is not explicitly passed, it is taken as 0. ... import numpy as np arr1 = np.array([1, 2, 3]) arr2 = np.array([4, 5, 6]) arr = np.concatenate((arr1, arr2)) print(arr) Try it Yourself »
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TutorialsPoint
tutorialspoint.com › numpy › numpy_concatenate.htm
Numpy Concatenate() Function
Following are the parameters of the Numpy concatenate() function − · a1, a2, ...: array_like : These are the arrays to be concatenated.
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NumPy
numpy.org › doc › 2.3 › reference › generated › numpy.concatenate.html
numpy.concatenate — NumPy v2.3 Manual
Concatenate function that preserves input masks. ... Split an array into multiple sub-arrays of equal or near-equal size. ... Split array into a list of multiple sub-arrays of equal size. ... Split array into multiple sub-arrays horizontally (column wise). ... Split array into multiple sub-arrays vertically (row wise). ... Split array into multiple sub-arrays along the 3rd ...
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NumPy
numpy.org › doc › 2.0 › reference › generated › numpy.concatenate.html
numpy.concatenate — NumPy v2.0 Manual
Concatenate function that preserves input masks. ... Split an array into multiple sub-arrays of equal or near-equal size. ... Split array into a list of multiple sub-arrays of equal size. ... Split array into multiple sub-arrays horizontally (column wise). ... Split array into multiple sub-arrays vertically (row wise). ... Split array into multiple sub-arrays along the 3rd ...
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Python Guides
pythonguides.com › python-concatenate-arrays
How to Concatenate Arrays in Python
August 20, 2025 - It has a built-in concatenate() function. import numpy as np arr1 = np.array([1, 2, 3]) arr2 = np.array([4, 5, 6]) result = np.concatenate((arr1, arr2)) print(result)
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Reddit
reddit.com › r/learnpython › how do i combine multiple numpy arrays into one?
r/learnpython on Reddit: How do i combine multiple numpy arrays into one?
September 15, 2023 -

I am trying to plot (using matplotlib) some data.

Using Numpy i have made a few sets of arrays with the mean of my data, and i now want to plot my means, but i can't seem to figure out how to plot data from multiple arrays in one plot, nor can i figure out how to combine my arrays, and have tried the np.concatenate function, but it ain't working.

help

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np.stack(), np.vstack(), np.hstack(), np.dstack(), np.concatenate(), np.column_stack(), np.row_stack(). One of those might work for your case. Just check out the examples for what might be analogous to your problem. Probably a horizontal stack if this is a 1D array (error message). Check out the left menu: https://numpy.org/doc/stable/reference/generated/numpy.stack.html#numpy.stack
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Please provide the code that you have tried so far and ideally some sort of example of what the data looks like and what exactly you try to archieve. but it ain't working. Why not? Do you not get the expected result? Do you get an error?
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Python Examples
pythonexamples.org › python-numpy-concatenate-arrays
Concatenate Arrays - Numpy
To concatenate arrays in NumPy, call numpy.concatenate() function, pass tuple of arrays to be concatenated, and the axis along which concatenation must happen, as arguments.
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Note.nkmk.me
note.nkmk.me › home › python › numpy
NumPy: Concatenate arrays with np.concatenate, np.stack, etc. | note.nkmk.me
February 4, 2024 - This article explains how to ... np.concatenate() can concatenate 2D arrays vertically or horizontally, and np.stack() can stack 2D arrays to create a 3D array....
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Tutorial Gateway
tutorialgateway.org › python-numpy-concatenate
Python numpy concatenate
September 24, 2019 - The Python Numpy concatenate function is used to join two or more arrays together and returns a concatenated ndarray as an output.
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GeeksforGeeks
geeksforgeeks.org › machine learning › numpy-concatenate-function-python
numpy.concatenate() function in Python - GeeksforGeeks
July 12, 2025 - The numpy.concatenate() function combines multiple arrays into a single array along a specified axis. This function is particularly useful when working with large datasets or performing operations that require merging data from different sources.
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Stack Overflow
stackoverflow.com › questions › 44517809 › concatenate-multiple-numpy-arrays-in-one-array
concatenate multiple numpy arrays in one array? - Stack Overflow
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As mentioned in the comments you could just use the np.array function:

>>> import numpy as np
>>> a = ([1,2,3,4,5])
>>> b = ([2,3,4,5,6])
>>> c = ([3,4,5,6,7])

>>> np.array([a, b, c])
array([[1, 2, 3, 4, 5],
       [2, 3, 4, 5, 6],
       [3, 4, 5, 6, 7]])

In the general case that you want to stack based on a "not-yet-existing" dimension, you can also use np.stack:

>>> np.stack([a, b, c], axis=0)
array([[1, 2, 3, 4, 5],
       [2, 3, 4, 5, 6],
       [3, 4, 5, 6, 7]])

>>> np.stack([a, b, c], axis=1)  # not what you want, this is only to show what is possible
array([[1, 2, 3],
       [2, 3, 4],
       [3, 4, 5],
       [4, 5, 6],
       [5, 6, 7]])
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Codecademy
codecademy.com › article › numpy-concatenate
How to Use np.concatenate() in NumPy (With Examples and Comparisons) | Codecademy
This function returns a new array that contains the concatenation of the given arrays. Next, let’s see an example that uses the np.concatenate() function to join two NumPy arrays vertically (axis=0):