Feng's Notes Isn't coding fun?

Kaggle竞赛指南 —— 主流机器学习算法

目前竞赛中(其实也是常规实际问题)的主流算法有四大门类: Linear, Tree-based, kNN 以及 Neural Networks 下面分别简单介绍一下:

Kaggle竞赛指南 —— 简介



Backward propagation of Neural Network explained

Backpropagation is the foundation of the deep neural network. Usually, we consider it to be kind of ‘dark magic’ we are not able to understand. However, it should not be the black box which we stay away. In this article, I will try to explain backpropagation as well as the whole neural network step by step in the original mathematical way.

Stochastic gradient descent

Stochastic Gradient decent is one of the fundamental algorithm in deep learning. It is used when we perform optimization of the cost function.Suppose the function is $ f(x) $


[Pandas]How to plot counts of each value

[Pandas]How to calculate datetime difference in years

Suppose you got a person’s regist time in one column and his birth date in another column, now you need to calculate his age when he did the registration. There are two ways to reach this result.

[Pandas]How to list all columns

[Pandas] How to import from Sql Server

We need to rely on pyodbc, the sample code is as belows.

Basics of words embedding

Why embedding

Natural language processing systems traditionally treat words as discrete atomic symbols, and this may lead to some obstacles in word preprocessing:

What is tf.data and how to use

Tf.data is a high level API provided by tensorflow, it performs as a pipeline for complex input and output. The core data structure of tf.data is Dataset which represents a potentially large set of elements.