different colors for each bar in stacked bar graph - base graphics

Question

I want to plot a stacked bar graph like the one attached, but I want the colors to vary between the categories aa, bb and cc. Specifically, I want the grey blocks in bb to be red and the grey blocks in cc to be green. The following code serves as a simple example and illustrates what I have already tried: ``` aa=c(0.2,0.6,0.1,0.1) bb=c(0.4,0.5,0.05,0.05) cc=c(0.5,0.25,0.1,0.15) x=cbind(aa,bb,cc) x #the data aa bb cc [1,] 0.2 0.40 0.50 [2,] 0.6 0.50 0.25 [3,] 0.1 0.05 0.10 [4,] 0.1 0.05 0.15 ``` default behavior, all blocks have the same color in each categories ``` col=rep(c("white","grey"),2) col # [1] "white" "grey" "white" "grey" barplot(x,col=col) ``` but I want the grey blocks in `bb` to be red and the grey blocks in `cc` to be green ``` col=cbind(rep(c("white","grey"),2),rep(c("white","red"),2),rep(c("white","green"),2)) col [,1] [,2] [,3] [1,] "white" "white" "white" [2,] "grey" "red" "green" [3,] "white" "white" "white" [4,] "grey" "red" "green" barplot(x,col=col) #not working…

Accepted Answer

A workaround: extend your matrix so that values correspond to fictitious categories, with just one color per category. Only one of `aa`, `bb` and `cc` will actually have data in those categories.

```
xx <- rep(0,4)
x <- matrix(c(aa,xx,xx,xx,bb,xx,xx,xx,cc),ncol=3)
x
      [,1] [,2] [,3]
 [1,]  0.2 0.00 0.00
 [2,]  0.6 0.00 0.00
 [3,]  0.1 0.00 0.00
 [4,]  0.1 0.00 0.00
 [5,]  0.0 0.40 0.00
 [6,]  0.0 0.50 0.00
 [7,]  0.0 0.05 0.00
 [8,]  0.0 0.05 0.00
 [9,]  0.0 0.00 0.50
[10,]  0.0 0.00 0.25
[11,]  0.0 0.00 0.10
[12,]  0.0 0.00 0.15
```

And plot as you did:

```
col <- c(rep(c("white","grey"),2),rep(c("white","red"),2),rep(c("white","green"),2))
barplot(x,col=col)
```

different colors for each bar in stacked bar graph - base graphics

Solution

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