scatter-plot

I am trying to plot two variables where N=700K. The problem is that there is too much overlap, so that the plot becomes mostly a solid block of black. Is there any way of having a grayscale "cloud" where the darkness of the plot is a function of the number of points in an region? In other words, instead of showing individual points, I want the plot to be a "cloud", with the more the number of points in a region, the darker that region. One way to deal with this is with alpha blending, which makes each point slightly transparent. So regions appear darker that have more point plotted on them.

Suppose I have three data sets: X = [1,2,3,4] Y1 = [4,8,12,16] Y2 = [1,4,9,16] I can scatter plot this: from matplotlib import pyplot as plt plt.scatter(X,Y1,color='red') plt.scatter(X,Y2,color='blue') plt.show() How can I do this with 10 sets? I searched for this and could find any reference to what I'm asking. Edit: clarifying (hopefully) my question If I call scatter multiple times, I can only set the same color on each scatter. Also, I know I can set a color array manually but I'm sure there is a better way to do this. My question is then, "How can I automatically scatter-plot my several

Is there a way of creating scatterplots with marginal histograms just like in the sample below in ggplot2 ? In Matlab it is the scatterhist() function and there exist equivalents for R as well. However, I haven't seen it for ggplot2. I started an attempt by creating the single graphs but don't know how to arrange them properly. require(ggplot2) x<-rnorm(300) y<-rt(300,df=2) xy<-data.frame(x,y) xhist <- qplot(x, geom="histogram") + scale_x_continuous(limits=c(min(x),max(x))) + opts(axis.text.x = theme_blank(), axis.title.x=theme_blank(), axis.ticks = theme_blank(), aspect.ratio = 5/16, axis