第六章 基本图形 本章概要 1 条形、盒形和点图 2 饼状和扇形图 3 直方图和核密度曲线图 本章所介绍内容概括如下。 数据可视化能够很好地理解数据。R提供了非常丰富的画图函数,通过图形可有助于理解分类变量和连续变量。 1 可视化变量分布 2 结果分组比较 条形图(Bar plot) 条形图通过垂直条或者水平条展示变量频次分布,形式如下。 barplot()。 举例说明如下。 数据源:使用vcd包里面的Arthritis数据集。 Arthritis数据集描述如下。 Data from Koch \& Edwards (1988) from a double-blind clinical trial investigating a new treatment for rheumatoid arthritis. Arthritis ID Treatment Sex Age Improved 1 57 Treated Male 27 Some 2 46 Treated Male 29 None 3 77 Treated Male 30 None 4 17 Treated Male 32 Marked 5 36 Treated Male 46 Marked 6 23 Treated Male 58 Marked 7 75 Treated Male 59 None 8 39 Treated Male 59 Marked 9 33 Treated Male 63 None 10 55 Treated Male 63 None 11 30 Treated Male 64 None 12 5 Treated Male 64 Some 13 63 Treated Male 69 None 14 83 Treated Male 70 Marked 15 66 Treated Female 23 None 16 40 Treated Female 32 None 17 6 Treated Female 37 Some 18 7 Treated Female 41 None 19 72 Treated Female 41 Marked 20 37 Treated Female 48 None 21 82 Treated Female 48 Marked 22 53 Treated Female 55 Marked 23 79 Treated Female 55 Marked 24 26 Treated Female 56 Marked 25 28 Treated Female 57 Marked 26 60 Treated Female 57 Marked 27 22 Treated Female 57 Marked 28 27 Treated Female 58 None 29 2 Treated Female 59 Marked 30 59 Treated Female 59 Marked 31 62 Treated Female 60 Marked 32 84 Treated Female 61 Marked 33 64 Treated Female 62 Some 34 34 Treated Female 62 Marked 35 58 Treated Female 66 Marked 36 13 Treated Female 67 Marked 37 61 Treated Female 68 Some 38 65 Treated Female 68 Marked 39 11 Treated Female 69 None 40 56 Treated Female 69 Some 41 43 Treated Female 70 Some 42 9 Placebo Male 37 None 43 14 Placebo Male 44 None 44 73 Placebo Male 50 None 45 74 Placebo Male 51 None 46 25 Placebo Male 52 None 47 18 Placebo Male 53 None 48 21 Placebo Male 59 None 49 52 Placebo Male 59 None 50 45 Placebo Male 62 None 51 41 Placebo Male 62 None 52 8 Placebo Male 63 Marked 53 80 Placebo Female 23 None 54 12 Placebo Female 30 None 55 29 Placebo Female 30 None 56 50 Placebo Female 31 Some 57 38 Placebo Female 32 None 58 35 Placebo Female 33 Marked 59 51 Placebo Female 37 None 60 54 Placebo Female 44 None 61 76 Placebo Female 45 None 62 16 Placebo Female 46 None 63 69 Placebo Female 48 None 64 31 Placebo Female 49 None 65 20 Placebo Female 51 None 66 68 Placebo Female 53 None 67 81 Placebo Female 54 None 68 4 Placebo Female 54 None 69 78 Placebo Female 54 Marked 70 70 Placebo Female 55 Marked 71 49 Placebo Female 57 None 72 10 Placebo Female 57 Some 73 47 Placebo Female 58 Some 74 44 Placebo Female 59 Some 75 24 Placebo Female 59 Marked 76 48 Placebo Female 61 None 77 19 Placebo Female 63 Some 78 3 Placebo Female 64 None 79 67 Placebo Female 65 Marked 80 32 Placebo Female 66 None 81 42 Placebo Female 66 None 82 15 Placebo Female 66 Some 83 71 Placebo Female 68 Some 84 1 Placebo Female 74 Marked > rm(list=ls()) > counts <- table(Arthritis$Improved) > counts None Some Marked 42 14 28 > par(mfrow=c(1,2)) > barplot(counts, main=”Simple Bar Plot”, xlab=”Improvement”, ylab=”Frequency”) > barplot(counts, main=”Horizontal Bar Plot”, xlab=”Frequency”, ylab=”Improvement”, horiz=TRUE) 效果图如图1所示。
注意:若是分类变量属于因子类型,没必要使用table()函数转换,直接使用barplot()函数绘图。 堆形或者分组条状图。 举例说明如下。 > rm(list=ls()) > library(vcd) Loading required package: grid > counts <- table(Arthritis$Improved, Arthritis$Treatment) > counts Placebo Treated None 29 13 Some 7 7 Marked 7 21 > barplot(counts, main=”Stacked Bar Plot”, + xlab=”Treatment”, ylab=”Frequency”, + col=c(“red”, “yellow”, “green”), + legend=rownames(counts)) > barplot(counts, main=”Stacked Bar Plot”, + xlab=”Treatment”, ylab=”Frequency”, + col=c(“red”, “yellow”, “green”), + legend=rownames(counts), beside=TRUE) 效果图如图2所示。
均值条状图,即每个条状表示均值指标。 举例说明如下。 > rm(list=ls()) > states <- data.frame(state.region,state.x77) > means <- aggregate(states$Illiteracy, by=list(state.region),FUN=mean) > means Group.1 x 1 Northeast 1.000000 2 South 1.737500 3 North Central 0.700000 4 West 1.023077 > means <- means[order(means$x),] > means Group.1 x 3 North Central 0.700000 1 Northeast 1.000000 4 West 1.023077 2 South 1.737500 |
|广告服务|关于我们|Archiver|手机版|小黑屋|大数据人 ( 鄂ICP备14012176号-2 )
GMT+8, 2024-5-4 04:46 , Processed in 0.186055 second(s), 21 queries .
Powered by 小雄! X3.2
© 2014-2020 bigdataer Inc.