作者：ahworld
链接：转换矩阵为ggplot2的输入格式
来源：微信公众号-seqyuan
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在使用ggplot2画图时，如果拿到的数据是N x N的，那么画图很不方便，需要转换成行列名称为新的列的标识
下面的代码提供了转换的方法
M1 <- data.frame(matrix(1:25,nrow=5,dimnames=list(c("R1","R2","R3","R4","R5"),c("S1","S2","S3","S4","S5"))))
M1$S1 <- c("A1","A1","A2","A2","A2")
M1$S2 <- c("B1","B1","B1","B2","B2")
M1
| S1 | S2 | S3 | S4 | S5 | |
|---|---|---|---|---|---|
| R1 | A1 | B1 | 11 | 16 | 21 |
| R2 | A1 | B1 | 12 | 17 | 22 |
| R3 | A2 | B1 | 13 | 18 | 23 |
| R4 | A2 | B2 | 14 | 19 | 24 |
| R5 | A2 | B2 | 15 | 20 | 25 |
rownames(M1) <- paste(rownames(M1), M1$S1, M1$S2, sep="-")
M2 <- subset(M1, select=c("S3","S4","S5"))
M2 <- as.data.frame(as.table(as.matrix(M2)))
M2
| Var1 | Var2 | Freq | |
|---|---|---|---|
| 1 | R1-A1-B1 | S3 | 11 |
| 2 | R2-A1-B1 | S3 | 12 |
| 3 | R3-A2-B1 | S3 | 13 |
| 4 | R4-A2-B2 | S3 | 14 |
| 5 | R5-A2-B2 | S3 | 15 |
| 6 | R1-A1-B1 | S4 | 16 |
| 7 | R2-A1-B1 | S4 | 17 |
| 8 | R3-A2-B1 | S4 | 18 |
| 9 | R4-A2-B2 | S4 | 19 |
| 10 | R5-A2-B2 | S4 | 20 |
| 11 | R1-A1-B1 | S5 | 21 |
| 12 | R2-A1-B1 | S5 | 22 |
| 13 | R3-A2-B1 | S5 | 23 |
| 14 | R4-A2-B2 | S5 | 24 |
| 15 | R5-A2-B2 | S5 | 25 |
library(stringr)
Var1 <- data.frame(str_split_fixed(M2$Var1, "-", 3))
M2 <- cbind(Var1, M2)
M2 <- M2[,-4]
M2
| X1 | X2 | X3 | Var2 | Freq | |
|---|---|---|---|---|---|
| 1 | R1 | A1 | B1 | S3 | 11 |
| 2 | R2 | A1 | B1 | S3 | 12 |
| 3 | R3 | A2 | B1 | S3 | 13 |
| 4 | R4 | A2 | B2 | S3 | 14 |
| 5 | R5 | A2 | B2 | S3 | 15 |
| 6 | R1 | A1 | B1 | S4 | 16 |
| 7 | R2 | A1 | B1 | S4 | 17 |
| 8 | R3 | A2 | B1 | S4 | 18 |
| 9 | R4 | A2 | B2 | S4 | 19 |
| 10 | R5 | A2 | B2 | S4 | 20 |
| 11 | R1 | A1 | B1 | S5 | 21 |
| 12 | R2 | A1 | B1 | S5 | 22 |
| 13 | R3 | A2 | B1 | S5 | 23 |
| 14 | R4 | A2 | B2 | S5 | 24 |
| 15 | R5 | A2 | B2 | S5 | 25 |
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