RG#44: Hexabin XY scatter plot and transparent point XY plot

# data
set.seed(1234)
x = rnorm(10000, 50, 30)
y = x*0.6 + rnorm (10000, 0, 30)
df <- data.frame(x,y)


ggplot(df,aes(x=x,y=y)) + stat_binhex() + theme_bw()

# vivid colored 
ggplot(df,aes(x=x,y=y)) + stat_binhex(colour="white",na.rm=TRUE) + scale_fill_gradientn(colours=c("green1","red"),name = "Frequency",na.value=NA)+ theme_bw()

# plot with transparency 
require(ggplot2)
ggplot(df,aes(x=x,y=y)) + geom_point(alpha = 0.3, col = "red") + theme_bw()

# in base

# data
set.seed(1234)
x = rnorm(10000, 50, 30)
y = x*0.6 + rnorm (10000, 0, 30)
df <- data.frame(x,y)


plot(df$x, df$y, pch = 19, cex = 1, col = rgb(0,1,0, alpha = 0.1))

# alpha function to introduce transparency
require(RColorBrewer)

add.alpha <- function(col, alpha=1){

  if(missing(col))

    stop("vector of colours missing")

  apply(sapply(col, col2rgb)/255, 2, 

                     function(x) 

                       rgb(x[1], x[2], x[3], alpha=alpha)) 

}

# POINT SIZE AND TRANSPARENCY 

plot (df$x, df$y, pch = 19, cex = 0.5, col = add.alpha ("red", 0.2))