# [Tutor] Pyuthon 3 Combine 1 D Arrays

Stephen P. Molnar s.molnar at sbcglobal.net
Thu May 18 08:07:04 EDT 2017

```On 05/17/2017 06:15 PM, Luis JM Amoreira wrote:
> Hi,
> If your arrays have shape (300,1) (single column, 300 rows right?) then
> M = numpy.hstack((array1, array2)) is an array with shape (300, 2) (300
> rows, 2 columns) and M.T is 2 by 300 [shape (2, 300)]. Take an example:
>
> In [11]: import numpy as np
>
> In [12]: a1=np.random.rand(3,1)
>
> In [13]: a1
> Out[13]:
> array([[ 0.09042866],
>         [ 0.63008665],
>         [ 0.99106757]])
>
> In [14]: a2=np.random.rand(3,1)
>
> In [15]: np.hstack((a1,a2))
> Out[15]:
> array([[ 0.09042866,  0.99965848],
>         [ 0.63008665,  0.12334957],
>         [ 0.99106757,  0.43502637]])
>
> In [16]: np.hstack((a1,a2)).T
> Out[16]:
> array([[ 0.09042866,  0.63008665,  0.99106757],
>         [ 0.99965848,  0.12334957,  0.43502637]])
>
> Hope this helps!
> ze
>
>
> On 05/17/2017 08:50 PM, Stephen P. Molnar wrote:
>> I'm beginning to think that I don't know how to ask the question as
>> Google and Stack Overflow have resulted in nothing.  All of the
>> results seem to deal with integers.
>>
>> I have a number of single column floating point arrays each containing
>> 300 entries that I want to combine into a n by 300 array where n is
>> the number of single column arrays.
>>
>> I have tried zip, np.concatenate etc with only failure.
>>
>>
>>
>>
>> _______________________________________________
>> Tutor maillist  -  Tutor at python.org
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>>
>

Here's what I get:

Traceback (most recent call last):

File "<ipython-input-7-5173f5e64beb>", line 1, in <module>

runfile('/home/comp/Apps/Python/Molecular_Transforms/Basic/MolT_app_1.py',
wdir='/home/comp/Apps/Python/Molecular_Transforms/Basic')

File
"/home/comp/Apps/anaconda3/lib/python3.6/site-packages/spyder/utils/site/sitecustomize.py",
line 880, in runfile
execfile(filename, namespace)

File
"/home/comp/Apps/anaconda3/lib/python3.6/site-packages/spyder/utils/site/sitecustomize.py",
line 102, in execfile

File
"/home/comp/Apps/Python/Molecular_Transforms/Basic/MolT_app_1.py", line
289, in <module>
f.write("\n".join("".join(map(str, x)) for x in (name_I_app)))

File
"/home/comp/Apps/Python/Molecular_Transforms/Basic/MolT_app_1.py", line
289, in <genexpr>
f.write("\n".join("".join(map(str, x)) for x in (name_I_app)))

TypeError: 'numpy.float64' object is not iterable

However, numpy.column_stack works.

Problem solved.

--
Stephen P. Molnar, Ph.D.		Life is a fuzzy set
www.molecular-modeling.net		Stochastic and multivariate
(614)312-7528 (c)
Skype: smolnar1
```