Note笔记

Notes on Creating Beautiful Heatmaps in R

By Ancheng|2018-08-31T12:20:23-04:00August 31st, 2018|Categories: Note笔记|Tags: Heatmap, heatmap.2, R|

Date: 2017/04/16 source: http://math.usu.edu/jrstevens/stat5570/2.3.Clustering.pdf # Heatmap Trial library(cluster) library(RColorBrewer) set.seed(123) x1 <- c(rnorm(20,sd=.05), rnorm(20,mean=1,sd=.05), rnorm(20,mean=1.5,sd=.05)) x2 <- 4+c(rnorm(20,sd=2), rnorm(20,mean=8,sd=1.5), rnorm(20,mean=8,sd=1)) x1.sc <- x1/sd(x1) x2.sc <- x2/sd(x2) hmcol <- colorRampPalette(brewer.pal(10,"RdBu"))(256) csc <- c(hmcol[50],hmcol[200]) # define side colors heatmap(cbind(x1.sc,x2.sc),scale="column",col=hmcol, ColSideColors=csc,cexCol=1.5,cexRow=.5) # ---- try with ALL datasets source("http://bioconductor.org/biocLite.R") biocLite(c('affy', 'ALL')) # download packages library(affy); library(ALL); data(ALL) gn <- featureNames(ALL) [...]

R for Data Science Study Notes

By Ancheng|2018-08-10T02:09:56-04:00August 10th, 2018|Categories: Note笔记|Tags: Data Science, Modelling, R, Visualiztion|

Just finished an amazing tutorial textbook in 3 consecutive days. is such a fantastic book for both beginners and mid-level learners like me to review all the aspects of Data Science using R systematically and grab a more thorough understanding of data tidying methods, how to treat different data format effectively and utilize dplyr, lubridate and [...]

XGBoost Note笔记

By Ancheng|2018-09-01T23:10:10-04:00August 3rd, 2018|Categories: Note笔记|Tags: Ensemble Tree Method, Gradient Boosting, python, Xgboost|

xgboost在代价函数里加入了正则项，用于控制模型的复杂度。正则项里包含了树的叶子节点个数、每个叶子节点上输出的score的L2模的平方和。

分享目前为止最易懂的Regularization讲解

By Ancheng|2018-07-31T20:34:46-04:00July 31st, 2018|Categories: Note笔记|Tags: L1, L2, Regularization|

下面推荐一个PPT Slide 帮助你们更好地理解正则化Regularization

Tensorflow for Deep Learning

By Ancheng|2018-07-27T08:45:08-04:00July 26th, 2018|Categories: Note笔记|Tags: python, Tensorflow|

3 or more Hidden Layer then you have a deep network Activation Function Hyperbolic Tangent: $$tanh(z)$$, where $$z = wx+b$$ cosh(x) = \frac{e^x + e^{-x}}{2} sinh(x) = \frac{e^x - e^{-x}}{2} tanh(x) = \frac{sinh(x)}{cosh(x)} The graph looks like this Rectified Linear Unit(ReLU): relatively simple function: max(0, z) Cost Function Quadratic Cost $$C = \sum(y-a)^2/n$$, where $$a$$ is [...]

如何学习SQL

By Ancheng|2018-07-26T21:41:25-04:00July 26th, 2018|Categories: Note笔记|Tags: SQL|

如何学习 SQL 语言？ - 知乎经典SQL练习题 - CSDN博客 sql练习网站 - CSDN博客 MySQL SQL常用语句自我测试练习-苦逼程序员-迈进-51CTO博客将MySQL安装到D盘 – 程泽群的博客 MySQL Commands sql 练习(五) - 简书经典SQL练习题查询Score表中的最高分的学生学号和课程号。（子查询或者排序） SELECT sno,cno FROM score WHERE degree =(SELECT MAX(degree) FROM score) select sno, cno from score order by degree desc limit 1,1; 查询Score表中至少有5名学生选修的并以3开头的课程的平均分数。 SELECT AVG(degree),cno FROM score WHERE cno LIKE '3%' GROUP BY [...]

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SQL Coding Challenge – Leetcode

By Ancheng|2018-07-26T21:39:33-04:00July 26th, 2018|Categories: Note笔记|Tags: Coding Challenge, leetcode, SQL|

Easy Difficulty Combine Two Tables - LeetCode SELECT FirstName, LastName, City, State FROM Person LEFT JOIN Address ON Person.PersonId = Address.PersonId; Second Highest Salary - LeetCode SELECT distinct(Salary) AS SecondHighestSalary FROM Employee UNION SELECT NULL ORDER BY SecondHighestSalary DESC LIMIT 1, 1; Employee Earning More Than Their Managers Assign two different names for single table and [...]

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Big Data Modelling & Management

By Ancheng|2018-07-27T08:46:28-04:00July 26th, 2018|Categories: Note笔记|Tags: Big Data, Data Management|

Data Model Basic Data Operations: selection, projection, union and join Sturctre Person{ firstName: string, lastName: string, DOB: date } Relational Data Model Represented as Table; relational tuple as row in the table Atomic: represent one unit of information and cannot be degraded further Header tells the constaints: ID: Int Primary Key | Fname: string Not null [...]

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