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I need to draw 3 different plots setting the same scale range color. I have 3 matrices with different range of values.

For example: 

range(matrixA) 
# 0.60 0.85  
range(matrixB) 
# 0.65 0.95  
range(matrixA) 
# 0.5 1.0

I would like to have the same color fill for the plots. For example, for all 0.8 value in the difference plots, if in the first plot 0.8 orange, I want all 0.8 value in different graphs to be the same orange.

My problem in this moment is:

In the first plot, the color of the max value is red, then the value 0.85 is red.

In the second plot, the max value is red but in this case the max value is 0.95 and the problem arises.

My code: 

mat.melted <- melt(matrixA)
colnames(mat.melted) <- c("p","c","v")
p <- ggplot(mat.melted, aes(x=c,y=p,fill=v) + 
         geom-tile() + 
         scale_fill_gradintn(limits = c(min(as.vector(matrixA)), max(as.vector(matrixA))), 
                             colors = c("yellow","orange","red"))
M--
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TheAvenger
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  • pls provide a [reproducible example](https://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example) by providing your data, or a simulation of them. Use `dput(mat.melted)` and paste the result in the question. Btw I suppose you are speaking about data.frames, not matrix-es – GGamba Jun 20 '17 at 14:28

1 Answers1

7

You need to set the same range (limits of color bar) for all of them and also specify the colors.

rng = range(matrixA, matrixB, matrixC)

And add this to your ggplot code:

g + scale_fill_gradient2(low="green", mid="lightblue", high="red", #colors in the scale
               midpoint=mean(rng),    #same midpoint for plots (mean of the range)
               breaks=seq(0,1,0.25), #breaks in the scale bar
               limits=c(floor(rng[1]), ceiling(rng[2])))

Example:

Below is an example that helps you to get what you want:

x <- matrix(60:85, 5)/100
y <- matrix(65:95, 5)/100
z <- matrix(50:100, 5)/100


rng = range(c((x), (y), (z)))

library(reshape)
library(ggplot2)

ggplot(data = melt(x)) + geom_tile(aes(x=X1,y=X2,fill = value)) +
  scale_fill_gradient2(low="green", mid="lightblue", high="red", #colors in the scale
                   midpoint=mean(rng),    #same midpoint for plots (mean of the range)
                   breaks=seq(0,1,0.25), #breaks in the scale bar
                   limits=c(floor(rng[1]), ceiling(rng[2]))) + #same limits for plots
                   ggtitle("X")

ggplot(data = melt(y)) + geom_tile(aes(x=X1,y=X2,fill = value)) +
  scale_fill_gradient2(low="green", mid="lightblue", high="red", 
                   midpoint=mean(rng),   
                   breaks=seq(0,1,0.25), 
                   limits=c(floor(rng[1]), ceiling(rng[2]))) +
                    ggtitle("Y")                  
  
ggplot(data = melt(z)) + geom_tile(aes(x=X1,y=X2,fill = value)) +
 scale_fill_gradient2(low="green", mid="lightblue", high="red", 
                   midpoint=mean(rng),    
                   breaks=seq(0,1,0.25), 
                   limits=c(floor(rng[1]), ceiling(rng[2]))) +
                    ggtitle("Z")

This will give you:

M--
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  • Can I ask for a suggestion on this post is about the labels of the legend. Say you wanted high average low instead of 1,0.5,0.0. Could you give suggestions on how you would achieve that? @Masoud – Cyrillm_44 Mar 16 '18 at 23:13
  • @Cyrillm_44 sure. look at this thread https://stackoverflow.com/questions/23635662/editing-legend-text-labels-in-ggplot – M-- Mar 27 '18 at 20:29