一. t-tests 这一部分我们使用分布在MASS包中的UScrime数据集.它是关于美国47个州在1960年时,关于惩罚制度对犯罪率的影响. Prob:监禁(坐牢)的概率: U1:14到24岁的城市那你的失业率: U2:35到39岁的城市男子的失业率: So:an indicator variable for Southern states 1. 独立的t-test(independent t-test) t.test(y~x,data) t.tset(y1,y2) 例01: > libra…

NumPy: Basic Statistics from:https://campus.datacamp.com/courses/intro-to-python-for-data-science/chapter-4-numpy?ex=13 Average versus median You now know how to use numpy functions to get a better feeling for your data. It basically comes down to im…

Spark MLlib提供了一些基本的统计学的算法,下面主要说明一下: 1.Summary statistics 对于RDD[Vector]类型,Spark MLlib提供了colStats的统计方法,该方法返回一个MultivariateStatisticalSummary的实例.他封装了列的最大值,最小值,均值.方差.总数.如下所示: val conf = new SparkConf().setAppName("Simple Application").setMaster(&quo…

三. 柱状图(Histogram) 1. hist():画柱状图 ·breaks(可选项):控制柱状图的小柱子的条数: ·freq=FALSE:基于概率(probability),而非频率(frequencies),绘制图形. ·还可以有其他参数,如:xlab,ylab,main,col,lwd... 2. lines():在已有图形上添加线条. 3. box():给已有图形添加一个框. 4. rug() 5. diff() 6.box() 例07: > par(mfrow=c(2,2))>…

1. 创建新的变量 variable<-expression expression:包含一组大量的操作符和函数.常用的算术操作符如下表: 例1:根据已知变量,创建新变量的三种途径 > mydata<-data.frame(x1=c(2,2,6,4),x2=c(3,4,2,8)) > mydata$sumx<-mydata$x1+mydata$x2 > mydata$meanx<-(mydata$x1+mydata$x2)/2 >> attach(myd…

elaborate:详细说明 Data TypesJava categorizes data into different types, and only certain operationscan be performed on a particular type of data. Data type: A set of values together with a set of operations on those values.Primitive Data Types There are…

For intergration tests, always remember when you create a 'mass' you should aslo clean up the 'mass'. For example when you start the server, you need to close the server after the tests. See the post: http://www.cnblogs.com/Answer1215/p/7554662.html…

1.What are “Parametric Statistics”? 统计中的参数指的是总体的一个方面,而不是统计中的一个方面,后者指的是样本的一个方面.例如,总体均值是一个参数,而样本均值是一个统计量.参数统计检验对总体参数和数据的分布进行假设.这些类型的测试包括学生的T测试和方差分析测试,假设数据来自正态分布. A parameter in statistics refers to an aspect of a population, as opposed to a statistic,…

#---------------------------------------------------------------------# # R in Action (2nd ed): Chapter 7 # # Basic statistics # # requires packages npmc, ggm, gmodels, vcd, Hmisc, # # pastecs, psych, doBy to be installed # # install.packages(c("ggm&…

#---------------------------------------------------------------------# # R in Action (2nd ed): Chapter 7 # # Basic statistics # # requires packages npmc, ggm, gmodels, vcd, Hmisc, # # pastecs, psych, doBy to be installed # # install.packages(c("ggm&…