Remove r.Peng's plots
Create R code file plot1.R

Plots the PNG graphic plot1.png
Create R code file plot2.R

Plots the PNG graphic plot2.png
Create R code file plot3.R

Plots the PNG graphic plot3.png
Create R code file plot4.R

Plots the PNG graphic plot4.png
Create plot1.png

Plot generated by plot1.R
Create plot2.png

Plot generated by plot2.R
Create plot3.png

Plot generated by plot3.R
Create plot4.png

Plot generated by plot4.R