1. Project background In recent years, with the development of social economy and the improvement of people’s living standards, environmental pollution has attracted more and more attention. Air pollution is one of the greatest environmental threats to human health, alongside climate change. It is estimated that exposure to air pollution causes 7 million premature deaths […]
Tag: factors
Looking for the other half in the Kingdom of Mathematics: finding the sum of true factors of an integer, algorithm optimization solution to the timeout problem
The Kingdom of Mathematics looks for the other half, finds the sum of the true factors of an integer, and optimizes the algorithm to solve the timeout problem. (This note is suitable for coders who are familiar with python strings and lists) [The details of learning are a joyful process] Python official website: python cutting […]
[High-order data structure] AVL tree {Concept and implementation; node definition; insert and adjust balance factors; rotation operations: left single rotation, right single rotation, left and right double rotation, right and left double rotation; verification and performance analysis of AVL tree}
AVL tree 1. The concept of AVL tree Although the binary search tree can shorten the search efficiency, if the data is ordered or close to ordered, the binary search tree will degenerate into a single branch tree. Searching for elements is equivalent to searching for elements in a sequence table, which is inefficient. Therefore, […]
Simple mathematical operation program written in C++ (simple operation program source code for common factors, average values, linear functions, quadratic functions, etc.)
After we learn the simple loop structure of cpp, we can create operations on common factors, common multiples, and average values. #include <bits/stdc + + .h> using namespace std; int main(){ cout<<“First enter 1 or 2 to represent the number of numbers, then press Enter and then enter the number (positive integer), all its common […]
10 Key Factors of Software System Scalability
As part of the principles of sound software design, this post will focus on scalability-one of the most critical elements for building robust, future-proof applications. Insert a message, recently opened a video account, less than 1000 followers, unable to apply for certification, colleagues who see it use your little hands that don’t write bugs to […]
Prime numbers (determining prime numbers, decomposing prime factors, sieving prime numbers)
Table of Contents 1. Determine the prime number Idea analysis Code 2. Decomposition prime factor Idea analysis Typical topics Code Three, prime number sieve classic topic Idea analysis 1. Naive sieve method 2. Elsieve sieve method 3. Euler sieve method 1. Determine the prime number Thinking Analysis Since the factors of each composite number appear […]
Use the DolphinDB TopN function to explore efficient alpha factors
DolphinDB already has a lot of window calculation functions, such as the sliding window calculation of the m series, the cumulative window calculation of the cum series, and the time window sliding calculation of the tm series. However, all such functions perform indicator calculations on all records in the window, which inevitably contains a lot […]
Correlation analysis heat map: ggplot2 package draws environmental factors and species correlation heat map/bubble map
Hello everyone, today I will introduce how to use R language to analyze the correlation between environmental factors and species, and use the ggplot2 package to draw heat maps and bubble maps to visualize the results of correlation analysis. The correlation heatmap style was inspired by an article in Microbiome magazine: Step1: Correlation analysis between […]
Biweekly competition 105 (greedy, memorized search => dynamic programming, subset backtracking, decomposing prime factors + union search)
Article directory Biweekly 105 [2706. Buy two chocolates](https://leetcode.cn/problems/buy-two-chocolates/) greedy [2707. Extra characters in a string](https://leetcode.cn/problems/extra-characters-in-a-string/) memory search Memory search ==> DP (recursion) [2708. The maximum strength of a group](https://leetcode.cn/problems/maximum-strength-of-a-group/) sort + greedy DFS enumerates all subsets Dynamic programming (O(n)) [2709. Greatest common divisor traversal](https://leetcode.cn/problems/greatest-common-divisor-traversal/) Decompose prime factor + union lookup Two-week competition 105 2706. Buy […]
Python: How to analyze the correlation coefficient between climate factors based on sliding window? (pixel by pixel)
Directory 01 A brief description of the conventional correlation coefficient 02 Correlation coefficient analysis under sliding window I recently dealt with the statistical analysis of some climate factors and encountered some problems, so please record them. 01 Simple description of conventional correlation coefficient Before studying the sliding window, let’s study the conventional correlation coefficient analysis. […]