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Questions tagged [numpy-ufunc]

Numpy universal functions are "vectorized" functions operating on elements (element by element) on a Numpy array.

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Faster loop operating on two values of an array

Consider the following function: def dostuff(n, f): array = numpy.arange(0, n) for i in range(1, n): # Line 1 array[i] = f(array[i-1], array[i]) # Line 2 return numpy.sum(array) How can…
Vincent
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Groupby and transform in pandas based on window conditions

Please help to find an optimal solution for this task. We have a pandas dataframe with two main date columns and many others (and >20mln rows). Here is a toy example of the dataset: df = pd.DataFrame({'date1': [pd.Timestamp('2021-04-15'),…
Ani
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I cannot run python runtests.py -v for testing numpy it giving me version issue

I want to run test for numpy library in my local machine but when I simple testing command like this command python runtests.py -v I am keep getting following error ` Building, see build.log... Traceback (most recent call last): File…
Ishaque3 Nizamani
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Is there a way either numpy where or numpy selection to sort an array by matching adjacent values

I have an array that represents a series of points. For the purpose of this question the first two columns of the array do not pertain to the problem. The array in question is: array([[1., 1., 4., 0., 0.], [1., 1., 8., 0., 0.], [1.,…
Sushi08
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How Can I Convert a String to a Ufunc?

I am trying to write a simple function that converts an input written in LaTeX to a ufunc that can be read by numpy. So far, I'm testing the function by converting \sin(x) to np.sin(x) (ignoring the conversion from {} to (). I'm not that familiar…
Unmaxed
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ufunc 'divide' not supported for the input types...... error problem while trying to get the NumPy average

I am new to Numpy and I have been trying to get the average of an array I derived from another array. This is the code that have been giving me error: "ufunc 'divide' not supported for the input types, and the inputs could not be safely coerced to…
Ayodeji Nicholas
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Strange Error when adding 2 numpy masked arrays

So i'm trying to add 2 numpy masked arrays together. The difficulty is that they have to be added as strings because im trying to get a binary code in the resulting output array. The code below is a simplified version of what i'm trying to do. The…
JacksonFreeman
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Numpy duck array with string dtype unexpectedly throws `numpy.core._exceptions._UFuncNoLoopError`

Here is a minimal working example of a simple numpy duck array that I've been using for numeric data. import numpy as np class DuckArray(np.lib.mixins.NDArrayOperatorsMixin): def __init__(self, array: np.ndarray): self.array = array …
Roy Smart
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How to compare two vectors using a combination of OR logic and sum

I am trying to apply a method that takes in two vectors and returns a resulting vector. Below is an example input and expected result: a = [ 1, 0, -1, 0, 0, 1] b = [ 0, 0, -1, 0, 1, -1] result = my_func(a, b) # [ 1, 0, -1, 0, 1, 0] My…
achtunette
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TypeError: bad operand type for unary -: 'list' python

I Keep getting this error, It's so simple and error is about (-x) in function but I don't know how I can fix it. Please help me. This is my code: import numpy as np x = list(np.arange(0, 1, 0.1)) print (x) def f(x): f = np.exp(-x) return…
Motahare
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lifetimes library - ISSUE of calculating CLV when using function: customer_lifetime_value of GammaGammaFitter

I'm trying to calculate CLV(Customer Life Value) using lifetimes python library so, I am fitting purchase behavior data on ParetoNBDFitter and fitting purchase price data on GammaGammaFitter. and When I'm trying to calculate CLV based on…
오진석
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Writing my own ufunc; ufunc not supported for the input types

I'm trying to write a C function that coverts numpy string array to a float array. How can I receive numpy's array in C as const char *? static void double_logitprod(char **args, npy_intp *dimensions, npy_intp* steps,…
Saurav Bhattarai
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Numpy apply along axis based on row index

Trying to apply numpy inbuilt function apply_along_axis based on row index position import numpy as np sa = np.array(np.arange(4)) sa_changed = (np.repeat(sa.reshape(1,len(sa)),repeats=2,axis=0)) print (sa_changed) OP: [[0 1 2 3] [0 1 2 3]] The…
data_person
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numpy.add.at slower than in-place add?

Proceeding from one of my earlier posts, I noticed that the operation np.add.at(A, indices, B) is a lot slower than A[indices] += B. def fast(A): n = A.shape[0] retval = np.zeros(2*n-1) for i in range(n): retval[slice(i,i+n)] +=…
Kevin
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Does Numba support in-built python function e.g. `setitem`

TypingError: Failed in nopython mode pipeline (step: nopython frontend) No implementation of function Function() found for signature: This error is encountered when tried to set all the elements less than a given…
Helal Uddin Mullah
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