Category "numpy"

How to use `cv2.findContours` in different OpenCV versions?

I am trying to use OpenCV with Python in order to detect squares in a live video feed from a Raspberry Pi camera. However, the cv2.GaussianBlur and cv2.Canny fu

How to fix IndexError: invalid index to scalar variable

This code generates error: IndexError: invalid index to scalar variable. at the line: results.append(RMSPE(np.expm1(y_train[testcv]), [y[1] for y in y_test])

2D array indexing

How can I do the indexing of some arrays used as indices? I have the following six 2D arrays like this- array([[2, 0], [3, 0], [3, 1], [5, 0], [5, 1

How to synchronize to curves on matplotlib?

I have two curves that have their maximum roughly at the same time, but I'd like to match them exactly. The first function, maxind, determines where the maximum

Debugging Numpy VisibleDeprecationWarning (ndarray from ragged nested sequences)

Since NumPy version 19.0, one must specify dtype=object when creating an array from "ragged" sequences. I'm faced with a large number of array calls from my own

Numpy where function multiple conditions

I have an array of distances called dists. I want to select dists which are within a range. dists[(np.where(dists >= r)) and (np.where(dists <= r + dr))]

How can I convert boolean values from np.diff() to the actual values

I have a numpy array of np.shape=(n,) I am attempting to iterate through each value of the array and subtract the 2nd value from the 1st, then see if the differ

How to copy a 2D array into a 3rd dimension, N times?

I'd like to copy a numpy 2D array into a third dimension. For example, given the 2D numpy array: import numpy as np arr = np.array([[1, 2], [1, 2]]) # arr.shap

How to scale a dataframe with datetime field in it (as a index)?

I want to scale a dataframe, which raises the error as in the title (or below). My data: df.head() timestamp open high low close volume 0 2020-06-2

Pyplot Imshow Autozoom to cut out Irregular NaN padding

I have the following code import matplotlib.pyplot as plt import numpy as np array = np.pad(np.random.rand(300,300),10,'constant', constant_values = nan) fi

Implement Relu derivative in python numpy

I'm trying to implement a function that computes the Relu derivative for each element in a matrix, and then return the result in a matrix. I'm using Python and

How do I convert numpy mgrid function as a function?

Here is the way how numpy.mgrid is used. grid = np.mgrid[x1:y1:100j , x2:y2:100j, ..., xn:yn:100j] However, I find this structure very irritating. Therefore, I

solving Ax =b for a non-square matrix A using python

I'm focusing on the special case where A is a n x d matrix (where k < d) representing an orthogonal basis for a subspace of R^d and b is known to be inside t

Updating a NumPy array with another

Seemingly simple question: I have an array with two columns, the first represents an ID and the second a count. I'd like to update it with another, similar arr

How to change array shapes in in numpy?

If I create an array X = np.random.rand(D, 1) it has shape (3,1): [[ 0.31215124] [ 0.84270715] [ 0.41846041]] If I create my own array A = np.array([0,1,2]

Numpy mask based on if a value is in some other list

I have searched high and low and just can't find a way to do it. (It's possible I was searching for the wrong terms.) I would like to create a mask (eg: [True F

Reading coef value from OLS regression results

I use pandas and statsmodels to do linear regression. However, i can't find any possible way to read the results. the results are displayed but i need to do som

How to fix Python Numpy/Pandas installation?

I would like to install Python Pandas library (0.8.1) on Mac OS X 10.6.8. This library needs Numpy>=1.6. I tried this $ sudo easy_install pandas Searching

How to find all neighbors of a given point in a delaunay triangulation using scipy.spatial.Delaunay?

I have been searching for an answer to this question but cannot find anything useful. I am working with the python scientific computing stack (scipy,numpy,matp

Adding a vector to matrix rows in numpy

Is there a fast way in numpy to add a vector to every row or column of a matrix. Lately, I have been tiling the vector to the size of the matrix, which can use