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numpy

How to one-hot-encode from a pandas column containing a list?

August 20, 2022 by Magenaut

I would like to break down a pandas column consisting of a list of elements into as many columns as there are unique elements i.e. one-hot-encode them (with value 1 representing a given element existing in a row and 0 in the case of absence).

Categories Python, Q&A Tags numpy, pandas, python, scikit-learn, sklearn-pandas Leave a comment

Performance of Pandas apply vs np.vectorize to create new column from existing columns

August 20, 2022 by Magenaut

I am using Pandas dataframes and want to create a new column as a function of existing columns. I have not seen a good discussion of the speed difference between df.apply() and np.vectorize(), so I thought I would ask here.

Categories Python, Q&A Tags arrays, numpy, pandas, performance, python Leave a comment

How to write a multidimensional array to a text file?

August 19, 2022 by Magenaut

In another question, other users offered some help if I could supply the array I was having trouble with. However, I even fail at a basic I/O task, such as writing an array to a file.

Categories Python, Q&A Tags file-io, numpy, python Leave a comment

How to count the occurrence of certain item in an ndarray?

August 19, 2022 by Magenaut

In Python, I have an ndarray y
that is printed as array([0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1])

Categories Python, Q&A Tags count, multidimensional-array, numpy, python Leave a comment

Computing the correlation coefficient between two multi-dimensional arrays

August 19, 2022 by Magenaut

I have two arrays that have the shapes N X T and M X T. I’d like to compute the correlation coefficient across T between every possible pair of rows n and m (from N and M, respectively).

Categories Python, Q&A Tags arrays, correlation, numpy, python, scipy Leave a comment

Compiling numpy with OpenBLAS integration

August 19, 2022 by Magenaut

I am trying to install numpy with OpenBLAS , however I am at loss as to how the site.cfg file needs to be written.

Categories Python, Q&A Tags atlas, blas, numpy, openblas, python Leave a comment

testing whether a Numpy array contains a given row

August 19, 2022 by Magenaut

Is there a Pythonic and efficient way to check whether a Numpy array contains at least one instance of a given row? By “efficient” I mean it terminates upon finding the first matching row rather than iterating over the entire array even if a result has already been found.

Categories Python, Q&A Tags numpy, python Leave a comment

What is the difference between flatten and ravel functions in numpy?

August 19, 2022 by Magenaut

flatten is a method of an ndarray object and hence can only be called for true numpy arrays.

Categories Python, Q&A Tags flatten, multidimensional-array, numpy, numpy-ndarray, python Leave a comment

binning data in python with scipy/numpy

August 19, 2022 by Magenaut

is there a more efficient way to take an average of an array in prespecified bins? for example, i have an array of numbers and an array corresponding to bin start and end positions in that array, and I want to just take the mean in those bins? I have code that does it below but i am wondering how it can be cut down and improved. thanks.

Categories Python, Q&A Tags numpy, python, scientific-computing, scipy Leave a comment

How to install python modules without root access?

August 19, 2022 by Magenaut

I’m taking some university classes and have been given an ‘instructional account’, which is a school account I can ssh into to do work. I want to run my computationally intensive Numpy, matplotlib, scipy code on that machine, but I cannot install these modules because I am not a system administrator.

Categories Python, Q&A Tags numpy, pip, python Leave a comment
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  1. michealSmith07 on Is there a way to dynamically refresh the less command?August 21, 2022

    That is a very nice post. I like this post.

  2. anonymous on Fix libwacom9 dependency issue when upgrade DebianJune 27, 2022

    saved my day!! Thanks for the help…

  3. sreedhar on Fix libwacom9 dependency issue when upgrade DebianMay 10, 2022

    Thanks its working

  4. saintnick on Fix libwacom9 dependency issue when upgrade DebianMay 10, 2022

    remove libwacom2 worked for me as well

  5. ranafoul on Fix libwacom9 dependency issue when upgrade DebianApril 22, 2022

    apt remove libwacom2 helped on kali 2022.01. gr8

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