Correlation Heatmaps in ggplot2 with custom colors

custom_coloring

#set up a coloring scheme using colorRampPalette
red=rgb(1,0,0); green=rgb(0,1,0); blue=rgb(0,0,1); white=rgb(1,1,1)
RtoWrange<-colorRampPalette(c(red, white ) )
WtoGrange<-colorRampPalette(c(white, green) ) 

p <- p + scale_fill_gradient2(low=RtoWrange(100), mid=WtoGrange(100), high="gray")
p

gistfile1.r

rm(list = ls())
library(ggplot2)
library(reshape2)
#help(package = "ggplot2")
data(movies)
movieGenres <- movies[c(18:23)] #subset to 6 genres

cor(movieGenres) # 6x6 cor matrix

#ggplot likes the data 'melted' one value per row
m <-melt(cor(movieGenres)) 
p <- ggplot(data=m, aes(x=Var1, y=Var2, fill=value)) + geom_tile()
p

heatmap.R

getwd()
rm(list = ls())
library(ggplot2)
library(reshape2)
#help(package = "ggplot2")
data(movies)
movieGenres <- movies[c(18:23)] #subset to 6 genres

cor(movieGenres) # 6x6 cor matrix

#ggplot likes the data 'melted' one value per row
m <-melt(cor(movieGenres)) 
p <- ggplot(data=m, aes(x=Var1, y=Var2, fill=value)) + geom_tile()
p

#set up a coloring scheme using colorRampPalette
red=rgb(1,0,0); green=rgb(0,1,0); blue=rgb(0,0,1); white=rgb(1,1,1)
RtoWrange<-colorRampPalette(c(red, white ) )
WtoGrange<-colorRampPalette(c(white, green) ) 
##

p <- p + scale_fill_gradient2(low=RtoWrange(100), mid=WtoGrange(100), high="gray")
p