Can I use PyTorch tensors instead of NumPy arrays while working with scikit-learn? I tried some methods from scikit-learn like train_test_split and StandardScalar, and it seems to work just fine, but is there anything I should know when I’m using PyTorch tensors instead of NumPy arrays? According to thi…
Tag: numpy
How to get multiple images from Flask request object at once in case of Content-Type:multipart/form-data?
I’m supposed to get multiple image files from the requests, but I can’t find a way to split a byte string request.files[key].read() properly to make np.ndarrays out of them. Answer files[key] gives only one object which has name=key in HTML, and .read() gives data only for this single file. So the…
Find center of blocks of ones in an 2d array
Lets assume I have the following array and want to get the center of each block of ones, so that I can get the following array: I already thought about using means or convolutions, but I couldn’t think of a really simple solution. One in efficient solution that I found is: Answer This is a little less i…
How can I select top k rows based on another dataframe in python?
I have data as follows. Users are 1001 to 1004 (but actual data has one million users). Each user has corresponding probabilities for the variables AT1 to AT6. I would like to select the top 3 users for each choice based on the following data. In the output, top1 to top3 are the top 3 users based on probabili…
Pandas: Unable to merge on two date columns
I have two dataframes that look like: df1: df2: Both date columns have been made using the pd.to_datetime() method, and they both supposedly have <M8[ns] data types when using df1.Date.dtype and df2.Date.dtype. However when trying to merge the dataframes with pd.merge(df,hpi,how=”left”,on=̶…
get first 2 characters of each index in array in python
I am trying to access the first two letters of each index in a numpy array in python: I have read previous forum of the error “‘int’ object is not subscriptable , I know it;s not a string, but for my work it’s better to be numpy.array or if anyone suggest me with another thing, please …
shrink and enlarge contour image with Python OpenCV
I have an image with an object like below: I can detect the contour and get a mask with only ball region, but my ROI is the edge region, that means I need a bigger and a smaller mask which combine to get this: so my question is: how can I shrink/enlarge the mask of contour around contour’s center? Answe…
Zipping two np.array into array
Im trying to combine following two np.arrays into a single array: The combination array must look like this [[i, pred, boxes],…]: I tried doing it this way, but it unfortunately didn’t work: Is there a way to do this? I tried other means but those tries were even worse. Answer Try hstack:
TypeError: cannot concatenate object of type ”; only Series and DataFrame objs are valid
I have a list of 10 dataframes named d0, d1, d2,…d9. All have 3 columns and 100 rows. I want to merge all dataframes so that I can have 3 columns and 1000 rows and then convert it into an array. The above code throws error: I used the solution suggested in pd.concat in pandas is giving a TypeError: cann…
Apply threshold for numpy.ndarray
I have a model predictions type of numpy.ndarray The predictions looks like where the first value of inner array corresponds to 0 class and the second value corresponds to 1 class. For this y_pred i need to apply FNR threshold 0.21552509277542697, which i also calculated. That is the efficient numpy way to do…