## [second hand car valuation in the second round of Mathorcup cup big data challenge] idea and Python implementation

Related links
(1)Question 1 complete idea and Python implementation code download
(2)Question 2: complete idea and Python implementation code download
subject
Question 1: Based on question 2 of the preliminary round, if you need to accurately predict the transaction cycle of vehicles, what method will you adopt for modeling? Please use ...

Added by **crishna369** on *Mon, 07 Mar 2022 21:02:34 +0200*

## Data dimensionality reduction: principal component analysis (PCA)

Holding fireworks to make a living, poetic to seek love
catalogue
1. Principle introduction
2. Detailed steps
2.1 data acquisition
2.2 data center (Standardization)
2.3 finding covariance matrix
2.4 calculate eigenvalues and eigenvectors of covariance matrix
2.5 determining the number of principal components
2.6 calculation of princi ...

Added by **TheUnknown** on *Sun, 06 Mar 2022 08:15:28 +0200*

## Grey correlation method -- matlab

catalogue
1. Introduction
2. Detailed explanation of algorithm
2.1 data standardization
2.2} calculate the grey correlation coefficient
2.3 calculation of grey correlation coefficient
3. Case analysis
3.1 reading data
3.2 data standardization
3.3} draw the broken line diagram of x1, x4, X5, X6 and X7
3.4 grey correlation coefficient
...

Added by **christh** on *Thu, 24 Feb 2022 15:56:49 +0200*

## Simulated annealing algorithm Python Programming multivariable function optimization

1. Simulated annealing algorithm
Simulated annealing algorithm draws lessons from the idea of statistical physics. It is a simple and general heuristic optimization algorithm, and has probabilistic global optimization performance in theory. Therefore, it has been widely used in scientific research and engineering. Annealing is a process in whi ...

Added by **AcidDriver** on *Fri, 18 Feb 2022 13:42:26 +0200*

## Air return problem of school bus transportation

Air return problem of school bus transportation
Record the code solution of problem A in the mathematical modeling competition of "University of Technology Press" in 2021
background
Every day, some teachers and staff of a school take a bus from the old campus to the new campus to work. After work, most people will return. The ...

Added by **meanrat** on *Fri, 18 Feb 2022 07:54:51 +0200*

## Python digital analog notes Sklearn sample cluster analysis

1. Classification of classification
Classification of classification? Yes, there are different kinds of classification, and it is often confused in the fields of mathematical modeling and machine learning.
First of all, let's talk about Supervised learning and Unsupervised learning. Does it mean that there are no teachers and Discipline Inspe ...

Added by **semlabs** on *Fri, 11 Feb 2022 09:33:14 +0200*

## Note | statistical learning method: Decision Tree

Basic concepts of decision tree
Decision tree is a tree.
The leaf node corresponds to the decision result, and each other node corresponds to an attribute test;The sample set contained in each node is divided into sub nodes according to the results of attribute test;The root node contains the complete set of samples, and the path from the roo ...

Added by **catlover** on *Thu, 10 Feb 2022 12:46:58 +0200*

## knn(k-nearest neighbor algorithm) -- matlab

catalogue
1. Basic definitions
2. Algorithm principle
2.1 advantages and disadvantages of the algorithm
2.2 algorithm parameters
2.3 variants
3. Distance formula in the algorithm
4. Case realization
4.1 reading data
4.2 separate training set and test set
4.3 normalization
4.4 calculating Euclidean distance
4.5 # sorting and outputti ...

Added by **rach123** on *Wed, 02 Feb 2022 15:13:25 +0200*

## First week of digital simulation training

Blanking of cans
Problem: a company uses a set of stamping equipment to produce a can for canned drinks, which is stamped with tinplate The can is cylindrical, including the can body, upper cover and lower bottom. The height of the can is 10 cm, and the diameters of the upper cover and lower bottom are 5 cm The company uses two different speci ...

Added by **pmjm1** on *Thu, 20 Jan 2022 11:40:26 +0200*

## 2021 may day cup mathematical modeling problem A vaccine production

2021 may day cup mathematical modeling problem A
Vaccine production issues
The novel coronavirus pneumonia has been a worldwide disaster and has brought serious disasters to the world. Countries have developed new vaccines to control the epidemic. It is assumed that vaccine production needs to go through four process flows: CJ1 station, CJ2 s ...

Added by **Lagreca** on *Thu, 23 Dec 2021 23:49:47 +0200*