# Questions tagged [numpy]

NumPy is the fundamental package for scientific computing with the programming language Python.

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### Python - How to efficiently bin multiple dependent variables to a common independent variable?

Setup: I have ~30 parameters (dependent variables) measured simultaneously along a common time axis with ~1Hz resolution (independent variable). I need to calculate bin averages for all parameters, ...
1answer
39 views

### Schelling's model of Segregation Python implementation with Geopandas

If you don't know what is Schelling's model of segregation, you can read it here. The Schelling model of segregation is an agent-based model that illustrates how individual tendencies regarding ...
2answers
48 views

### Read coordinates from many files and calculate polygon areas

My goal with this snippet is to create an array of coordinates which in turn is a tuple of 68 elements, area and modified area array for all 10k elements and assign it to the ...
1answer
69 views

### Game of life using NumPy

I'm trying to improve my Game of life program for school in Python, to be able to run it quicker. So if you have some ideas, I will be glad to hear them. My current code: ...
1answer
136 views

### Bilinear image interpolation

I have written a bilinear interpolant, which is working moderately well except that is painfuly slow. How can rewrite the code to make it faster? Using opencv directly isn't a valid answer. ...
2answers
59 views

### Grouping sorted coordinates based on proximity to each other

I created an algotrithm that groups a sorted list of coordinates into buckets based on their proximity (30) to one another. Steps: Create a new key with a list ...
1answer
76 views

### Evaluate joint probability density function of a Markov random field

The following code evaluates probability mass function for all possible states of a model. ...
2answers
80 views

### Find the next predicted time a satellite is going to take picture of place

create a function which predicts the next time a satellite image will be taken of a certain location. When there is enough data to do so, the function should print a prediction for when the next ...
1answer
55 views

### Hurst Exponent calculator

I am aiming to compute the Hurst Exponent of a 1-D signal time series in Python. For now, I have one existing function hurst(sig) which returns the Hurst exponent ...
1answer
30 views

### Converting string of hex values to numpy array of specific shape

I am working on a project that needs to take a .bdf font file and turn it into a Numpy array. I am using the code below to turn the bitmap for the font into a numpy array. It currently works, I just ...
1answer
45 views

### Trapezoidal rule for set of data

Here is the question from the book of Mark Newman-Computational Physics Exc 5.1 a) Read in the data and, using the trapezoidal rule, calculate from them the approximate distance traveled by the ...
2answers
93 views

### Calculate mean and standard error of a generator in Python

The goal of the following code is to calculate the mean and the standard error of vectors of randomly-generated numbers. I am looking for feedback both on the correctness of the calculation, and on ...
0answers
27 views

### Parsing and plotting with numpy (or pandas)

I am trying to improve the following code to make it more broadly applicable and quick to use. ...
2answers
110 views

### Performance issues with double for loops, EM-algorithm

The alpha that I create is not created in a crazily efficient way I know, but the main bottleneck in this code is in what I call the "Maximization step" (see comments in code). There are double for-...
1answer
77 views

### Optimising iteration and substitution over large dataset

I have the following code: ...
1answer
50 views

### Nested list performance tuning

I need to make a function like these two, but at least an order of magnitude faster in python. Any tips or tricks? These functions inputs are nested lists, like: ...
1answer
64 views

### Generating Latin hypercube samples with numpy

I wrote some code to generate Latin hypercube samples for interpolation over high-dimensional parameter spaces. Latin hypercubes are essentially collections of points on a hypercube that are placed on ...
3answers
888 views

### KenKen solver - Python

Here is my code for the KenKen puzzle: The user must fill in each embolded regions with numbers in the range 1-n where n is the board dimensions (e.g: 4*4, n=4) ...
1answer
87 views

### Agent based model in Python

My model is based on the Ultimatum Game. I won't go into the intuition behind it but generally speaking it functions as follows: The game consists of a n × n lattice on which an agent is placed at ...
0answers
35 views

### Implementing a tic tac toe board in python

This is my attempt at making a class to represent a game board for tic tac toe. I normally hate while loops but I used one because I cant seem to make the ...
0answers
31 views

### Sortings stocks into quantiles based on their signal

This function sorts stocks into quantiles. To do so I used this function that accepts sig_df (dataframe with the timeseries of stocks signal) and number of ...
1answer
45 views

### Grid class for games using python

I made this class to eventually create a tic tac toe game. I used numpy which is a first for me. Here it is: ...
1answer
38 views

### Efficient resampling of time series

I'm trying to create an efficient function for re-sampling time-series data. Assumption: Both sets of time-series data have the same start and end time. (I do this in a separate step.) Resample ...
1answer
64 views

### Pad a ragged multidimensional array to rectangular shape

For some machine learning purpose, I need to work with sequences with different lengths. To be able to process efficiently those sequences, I need to process them in batches of size ...
2answers
113 views

### Positive cumulative sum of difference

I have a water reservoir with input and output rates. I want to determine when the input is exceeding the output by a certain constant. To accomplish this, I need to cumulatively sum all cases where ...
1answer
49 views

### Select optimal piecewise regression fit

I'm making a program which fits a piecewise linear regression with up to 4-5 breakpoints in the data, and then deciding how many breakpoints is best to prevent over and underfitting. However, my code ...
3answers
136 views

### Python solution for the N-Queens challenge

Here is my coded solution for the N-queens challenge The n-queens puzzle is the problem of placing n queens on an n×n chessboard such that no two queens attack each other. The program outputs all ...
0answers
62 views

### Optimising Probabilistic Weighted Moving Average (PEWMA) df.iterrows loop in Pandas

I'm implementing the Probabilistic Exponentially Weighted Mean for real time prediction of sensor data in pandas but have issues with optimising the pandas notebook for quick iterations. Is there a ...
1answer
92 views

### Choosing evenly distributed points from a million points on a sphere

I have $10^5$ to $10^6$ points on a sphere, and want to choose some points from them which are as close as uniformly distributed as possible. For that reason, I do the following: at each step I ...
1answer
55 views

### Gravity simulation using Numpy and Pygame

This is a simple gravity simulator coded in Python 3.7 using Numpy and Pygame. I was wondering if it can be optimized further. Initially I had coded it using pure Python lists, using nested loops to ...
0answers
60 views

### Numerical integration in cython

I have a set of nested functions that I need to call multiple times. I know scipy.quad is pretty fast, but I will need to call the integrator recursively and want ...
0answers
55 views

### Find indices using for loop

I should estimate the effect of B fields on particle deflection using $F=V \times B \times Force$. I have a 2D mesh with $n_x$ and $n_y$ which show the number of points in each direction. $B$ ...
0answers
47 views

### Python list operation - merge adjacent cubes into minimum number of shapes

I am hoping to find a way to make the process a lot faster. The lists are made of rows of 6 numbers, i.e. [[float] * 6, ...]. The intent is to pass a list of cube ...
2answers
87 views

### 3D metrics for segmentation evaluation

I am new to programming and I am trying to develop a machine learning approach for image segmentation (https://en.wikipedia.org/wiki/Image_segmentation) and here I want to evaluate the predicted (...
0answers
45 views

### Extract cell values from multiband rasters

I have the following function and code snippet to extract cell values for multiple years, format it, and save to a list. Each raster has 365 bands — one for each day. A separate operation is performed ...
0answers
168 views

### Population dynamic simulation on biological information maintenance 2

This question is the follow-up to this previous question. Background Using this simulation I investigate a system in which enzymes proliferate in cells. During the replications of enzymes, ...
1answer
55 views

### U-Net: A TensorFlow model

What I want to know I am writing a ML model called U-Net with Python (and TensorFlow). My question is not about the machine learning or Tensorflow, I want to know the best structure of the code. I ...
1answer
153 views

### Population dynamic simulation on biological information maintenance

Background Using this simulation I investigate a system in which enzymes proliferate in cells. During the replications of enzymes, parasites can come to be due to mutation. They can drive the system ...
2answers
75 views

### Birthday paradox simulation

I'm writing a simulator which checks how many balls we need to occupy every box or how many balls we need for any box has at least 2 balls (birthday paradox). I wrote the script in python and it is so ...
2answers
196 views

### Improve Performance of Comparing two Numpy Arrays

I had a code challenge for a class I'm taking that built a NN algorithm. I got it to work but I used really basic methods for solving it. There are two 1D NP Arrays that have values 0-2 in them, ...
1answer
118 views

### Longest carbon chain

My Code measures the longest path, not allowing cycles. For the example input below, the longest chain would be 4 Please can you review my code? ...
1answer
205 views

### Deep Neural Net implementation in Python3

I created my first implementation of an arbitrary feed forward neural network with a simple back-propagation training implementation. ...
0answers
77 views

### Cubic spline interpolation in Python from scratch

I implemented the cubic spline interpolation explained in https://en.wikipedia.org/wiki/Spline_interpolation as a Python class. Of course, such an interpolation should exist already in some Python ...
0answers
21 views

### TensorFlow regressor to predict probability of winning, given a current score

This is a TensorFlow regressor that tells me that if you get x score, you will have x% to win a game in x game(game is not important). Doing this as a project to learn tensorflow. ...
0answers
11 views

### Super-minimal implementation for inference only of fully a connected neural network in Python + Numpy

There are a lot of Neural Networks Frameworks available but in order to understand how things work internally reimplementing can be a good exercise In this case the goal is to develop a super-...
0answers
34 views

### N-D Kalman Filter in Python + Numpy

Just implemented this Kalman Filter in Python + Numpy keeping the Wikipedia notation It's a pretty straightforward implementation of the original algorithm, the goals were develop skills related to ...
1answer
175 views

### Searching extreme points of polyhedron

In my Uni, my scientific professor asked me to make some researches about the extreme points of polyhedrals. And I did them. I found that there is still no code in public for searching extreme points ...
1answer
78 views

### Aggregate Pandas Columns on Geospacial Distance

I have a dataframe that has 3 columns, Latitude, Longitude and Median_Income. I need to get the average median income for all points within x km of the original point into a 4th column. I need to do ...
1answer
1k views

### Factorio analysis: data munging

This project is... a little ridiculous. It's working, but it's a complete mess. Data about Factorio's game economy are pulled from the wiki via the MediaWiki API, scrubbed, preprocessed, and thrown ...
0answers
38 views

### Compare every combination of variables within the powerset

I have some survey data that represents individual's responses to multiple survey questions. There are about 10,000 people in my actual dataset, and each person answered 35 questions. From these 35 ...