Stacked Barplot together with Line in R

Question

I want to make the following stacked bar plot together with line curve.

But why this following code does not work? What's the right way to do it?

x<-c(0,1,2,3,4,5,6,7,8,9,10,11,12);

    # To plot line 
    emp_dens <- c(0.107,0.184,0.205,0.185,0.138,0.091,0.049,0.023,0.01,0.0028,0.0012,0.00023,0.00013);
    dat_dens <- as.matrix(cbind(x,emp_dens));


    # To plot stack bar
    dens_all_k <- c(1.15e-01, 1.89e-01, 2.05e-01, 1.82e-01,1.36e-01,8.68e-02,4.71e-02,2.21e-02,9.17e-03,3.37e-03,1.11e-03,3.37e-04,9.31e-05)

    # Each k0..5 compose the stack 
    # For example
    # dens_k0[1] + .... dens_k5[1] ~= dens_all_k[1]

    dens_k0 <-c(2.52e-02,8.38e-02,1.38e-01, 1.53e-01,1.27e-01,8.44e-02, 4.66e-02, 2.21e-02, 9.16e-03, 3.37e-03,1.11e-03, 3.37e-04, 9.31e-05)
    dens_k1 <- c(6.75e-02, 8.91e-02, 5.86e-02, 2.51e-02, 8.59e-03,2.25e-03, 4.90e-04,9.35e-05, 1.55e-05,2.21e-06,2.99e-07, 3.55e-08,3.92e-09)
    dens_k2 <- c(1.70e-02,1.64e-02,7.95e-03, 2.56e-03,6.20e-04,1.20e-04, 1.93e-05, 2.67e-06, 3.23e-07,3.47e-08,3.36e-09, 2.95e-10,2.38e-11)
    dens_k3 <- c(0.005124596,0,0,0,0,0,0, 0, 0, 0, 0,0,0)
    dens_k4 <- c(0.0004270497, 0, 0,0,0, 0, 0, 0, 0,0,0, 0, 0)
    dens_k5 <- c(2.760725e-05, 0, 0, 0,0,0, 0, 0, 0, 0,0, 0,0)


    barplot(cbind(0:max(x),dens_all_k),xlim=c(0,max(x)),ylim=c(0,max(emp_dens)),,space=0.1,lwd=5,xlab="Value of X",ylab="Densities",font.main=1);
    lines(dat_dens,lty=1,col="red");

Answer 1

dens_all_k contain only the aggregate summary. If you are looking for the barplot in the picture you need to supply all k information. Try the following code.

dens_kall<-rbind(dens_k0,dens_k1,dens_k2,dens_k3,dens_k4,dens_k5)
ltext<-c("K0","K1","K2","K3","K4","K5")
colnames(dens_kall)<-0:12
barplot(height=dens_kall,xlim=c(0,max(x)),ylim=c(0,max(emp_dens)),,space=0.1,lwd=5,xlab="Value of X",ylab="Densities",font.main=1
        ,legend.text =ltext,
        args.legend = list(x = "topright")
        );
lines(dat_dens,lty=1,col="red");

The output is

Answer 2

In barplot you don't pass a matrix with your x, and y values but just your heights. It doesn't make sense that you make all of the dens_k0 etc. items and never use them. Try...

barplot(rbind(dens_k0, dens_k1, dens_k2, dens_k3, dens_k4, dens_k5), xlim=c(0,max(x)), ylim=c(0,max(emp_dens)), space=0.1, lwd=5, xlab="Value of X", ylab="Densities", font.main=1)
lines(emp_dens,lty=1,col="red")

Carefully examine what I passed there for future reference. You probably need to set the legend argument of barplot to make it remotely readable. Even as it is those last few densitites are very very small.

An easy way to add the legend is to just make a couple of small changes to what you have.

barplot(rbind(dens_k0, dens_k1, dens_k2, dens_k3, dens_k4, dens_k5, 0), 
       col = c(grey(exp((0:5)/5) / exp(1)), 'red'), xlim=c(0,max(x)), ylim=c(0,max(emp_dens)), space=0.1, lwd=5, xlab="Value of X", ylab="Densities", font.main=1, 
       legend.text = c('k0', 'k1', 'k2', 'k3', 'k4', 'k5', 'dens curve'))