t = seq( 0, +8, length.out=1000 )
f = rep( 0, length(t) )

f[ (0 <= t) & (t < 2) ] = t[ (0 <= t) & (t < 2) ]
f[ (2 <= t) & (t < 5) ] = 2
f[ (5 <= t) & (t < 7) ] = 7 - t[ (5 <= t) & (t < 7) ]

#postscript("../../WriteUp/Graphics/Chapter6/chap_6_sect_3_prob_12_plot.eps", onefile=FALSE, horizontal=FALSE)
plot( t, f, type='p', cex=0.25, pch=20, col='black' )
points( c(0, 2, 5, 7), c(0, 2, 2, 0), pch=20, col='black', cex=1.5 )
grid()
#dev.off()