## 2-D Plotting
# Read the data from a dat file.
pd = read.table("../matlabdata.dat")
# Basic plotting of y vs x
dev.new()
plot(pd[,1],pd[,2], xlab="x", ylab="y")
dev.new()
x1  = seq(-2*pi, 2*pi, 4*pi/1024)
y1 = x1 * sin(x1^2)
# now a better plot
plot(x1,y1, type="l",xlab="x", ylab="f(x)", col="blue", main="Graph of f(x)=x sin(x^2)", lwd=2)
grid(nx=NULL,ny=NULL, lty=2, lwd=1, col="gray60", equilogs=TRUE)

# To save the plots
png("r_fig_1.png")
plot(pd[,1],pd[,2], xlab="x", ylab="y")
dev.off()

png("r_fig_2.png")
plot(x1,y1, type="l",xlab="x", ylab="f(x)", col="blue", main="Graph of f(x)=x sin(x^2)", lwd=2)
grid(nx=NULL,ny=NULL, lty=2, lwd=1, col="gray60", equilogs=TRUE)
dev.off()