I have two numpy arrays of the following shape: Array a is empty, as I just need this predefined shape, I created it with: Now I would like to copy data from array b to array a so that the second and third dimension of array a gets filled with the same 3 values of the corresponding row of array
Tag: numpy
Error when trying to set column as index in pandas dataframe
I have the following code: which works fine until I do (trying to set column ‘idx’ as in index for the dataframe) which throws an error What does this mean ? Answer The error is when you create A with If you print A.columns you will get: So ‘idx’ is not really in your column for you to set index.
Listing each iteration of rolling a six-sided-die in Python
I’m working on an animated bar plot to show how the number frequencies of rolling a six-sided die converge the more you roll the die. I’d like to show the number frequencies after each iteration, and for that I have to get a list of the number frequencies for that iteration in another list. Here’s the code so far: Output:
How to use pd.data_range() with a frequency of X minutes/hours/seconds?
I need to create a frequent date range with pandas date_range(). This works well with frequency=… parameter. But sometimes my code needs these frequent ranges in longer frequencys. for example 4 Hours or 5 minutes instead of one. How can I do that with pd.date_range(first_X_datetime, last_X_datetime, freq=frequency)? If there is not a more efficient way, my idea would be to
Merge two Lists of different size
I have an issue with some part of my code, I’m fetching two apis and then mixing the results in one array: Initialy the two arrays seems like this (although they can be empty or with more or less data): Their shapes are: So of course, when I try to append them in the 2nd dimension: I get this error:
Curve Fitting using Numpy Polyfit, estimate constant on function with Square Root
First of All, Sorry for my poor English and Thanks for clicking this Question. I already have x and y data sets, so I want to do curve fitting with my data sets. and estimated Model is then How can I estimate constants of this Model by polyfit? I know means Linear Equation Estimating. (1 means Linear) but How can
Python matrix multiplication: sparse multiply dense
Given the code snippet: where A is a CSR scipy sparse matrix, M and T are two numpy arrays. Question: During the matrix operations, does numpy treat A as a dense matrix, or M and T as two sparse matrices? I suspect that the latter case is true since the resulting matrix B is not in the sparse format. I
Custom data generator
I have a standard directory structure of train, validation, test, and each contain class subdirectories. I want to use the flow_from_directory API, but all I can find is an ImageDataGenerator, and the files I have are raw numpy arrays (generated with arr.tofile(…)). Is there an easy way to use ImageDataGenerator with a custom file loader? I’m aware of flow_from_dataframe, but
Numpy assignment of 3D array values using 2D index array
I have a 3D numpy array of zeros, with dimensions CxHxW (in this example, C=4, H=2, and W=3): I also have a 2D array of indices, with dimensions HxW, such that every value in the array is a valid index between [0, C-1] Is there a fast way, using vectorization, to modify array A such that A[B[i][j]][i][j] = 1, for
How to import csv format Adjacency Matrix hashtag network in CSV file?
My hashtag co-occurrence network is stored as an adjacency matrix in CSV format like this. Then I use this page as a reference Plot NetworkX Graph from Adjacency Matrix in CSV file I want to import this matrix into networkx and I tried this: But I only got this: How can I import my data correctly, I want to use