RG#72: XY plot with heatmap strip at margin

set.seed(1234)
mydata <- data.frame (Xv = rnorm (300, 50, 10), Yv = rnorm (300, 10, 3))
mydata$xcat <- cut (mydata$Xv, 10)
mydata$ycat <- cut (mydata$Yv, 10)



# plot 

require(ggplot2)
require(grid)

#Scatter plot without axis titles
p<-ggplot(mydata, aes(x=Xv, y=Yv)) +    geom_point(shape=19)  +
  theme_bw() 

#tile plot for the x axis
px<-ggplot(mydata,aes(x=xcat,y=1,fill=xcat))+geom_tile()+
  scale_x_discrete(expand=c(0,0))+
  scale_fill_hue(h=c(0,120))+
  scale_y_continuous(expand=c(0,0),breaks=1,labels="10")+
  theme(legend.position="none",
        axis.title=element_blank(),
        axis.text.x=element_blank(),
        axis.ticks.x=element_blank(),
        axis.text.y=element_text(color="white"),
        axis.ticks.y=element_line(color="white"))

#tile plot for the y axis
py<-ggplot(mydata,aes(x=1,y=ycat,fill=ycat))+geom_tile()+
  scale_y_discrete(expand=c(0,0))+
  scale_x_continuous(expand=c(0,0),breaks=1,labels="1")+
  scale_fill_hue(h=c(181,360))+
  theme(legend.position="none",
        axis.title=element_blank(),
        axis.text.y=element_blank(),
        axis.ticks.y=element_blank(),
        axis.text.x=element_text(color="white"),
        axis.ticks.x=element_line(color="white"))

#Define layout for the plots (2 rows, 2 columns)
layt<-grid.layout(nrow=2,ncol=2,heights=c(7/8,1/8),widths=c(1/8,7/8),default.units=c('null','null'))
#View the layout of plots
grid.show.layout(layt)

#Draw plots one by one in their positions
grid.newpage()
pushViewport(viewport(layout=layt))
print(py,vp=viewport(layout.pos.row=1,layout.pos.col=1))
print(p,vp=viewport(layout.pos.row=1,layout.pos.col=2))
print(px,vp=viewport(layout.pos.row=2,layout.pos.col=2))