coloring plot by selected range

0
votes

I have very specific ranges I would like to plot in different colors on the same plot using the plot function in R.

The ranges are in a matrix that looks like this:

x
     [,1] [,2]
[1,]    0  600
[2,]  700  900
[3,]  950 1000
[4,] 1200 1400

I have a data frame that looks like this: 

head(df)
  V1   V2  V3 V4 V5 V6
1  0 -280 -93  3  x x        
2  1 -279 -93  2  y y        
3  2 -278 -93  1  z z

I would like plot column V2 and I would like 5 different colors in the plot: 1 color for position df$V2 0-600, 1 color for 700-900, 1 color for 950-1000, and one color for 1200-1400, and another color for everything else that is not in those ranges (black for example).

I have other matrices that have different sizes, so ideally the code can be used for different amounts of ranges.

2
rmatrixplot
Are you plotting points? lines? What's the x and what's the y in the plot? Three rows isn't a super helpful dataset to test with given that zero points line in any of the specified boundaries. – MrFlick
Your ranges aren't closed. What do you want when, e.g., V2 is between 600 and 700, or between 900 and 950?? – jlhoward
I am plotting lines using plot(df$V2, type='l'). The x-axis is just an index. The column I'm printing has values that range from -300 to +2000 – user3141121
if V2 is between 600 and 700 I want that segment of the plot to be a different color – user3141121

2 Answers

1
votes

Something like this?

x1 <- matrix(c(0, 600, 700, 900, 950, 1000, 1200, 1400),
             nrow=4, ncol=2, byrow=TRUE)
y1 <- seq(-300, 2000)
plot(y1, y1, lwd=1)
for (i in 1:nrow(x1)){
    y2 <- y1[y1 >= x1[i, 1] & y1 <= x1[i, 2]]
    lines(y2, y2, col=i+1, lwd=10)
}

giving

enter image description here

0
votes

Just for the sake of having several solutions at hand:

x1 <- matrix(c(0, 600, 700, 900, 950, 1000, 1200, 1400),
             nrow=4, ncol=2, byrow=TRUE)
y1 <- seq(-300, 2000)
a <- sapply(y1,function(i)i>=x1[,1]&i<=x1[,2])
col <- apply(a,2,function(x)ifelse(any(x),which(x),0)) #Pick which group each element belongs to, if none assigns "0".
plot(y1,col=col+1)

enter image description here