#
#  Plots comparing Reliability vs. Effort for Recovery Blocks and
#           N-Version Programming under different assumptions
#  Created for cs497LS Spring 1999
#  David Stott

set logscale y 
coverage = .95

set title "Effect of Coverage on RB (3 versions for cost of 1): Prob. (1 - R) vs. Effort"
set xlabel "Effort"
set ylabel "Prob. Fail (log plot)"


# reliability
        r(x) = (1-exp(-x/3))
# prob[failure]
        p(x) = 1-r(x)
# prob[fail] with 1/3 effort
        q(x) = exp(-x)


# rec block
 f(x) = (r(x))*(1-p(x)*p(x)*p(x)*coverage*coverage*coverage)/(1-p(x)*coverage)
# 3 version
 g(x) = 3*r(x)*r(x)*(1-r(x)) + r(x)*r(x)*r(x)
# 1 version
 h(x) = 1-q(x)
# rb 3 for the price of 1
 j50(x) = (1 - q(x))*(1-q(x)*q(x)*q(x)*.5*.5)/(1-q(x)*.5)
 j90(x) = (1 - q(x))*(1-q(x)*q(x)*q(x)*.90*.90*.90)/(1-q(x)*.90)
 j95(x) = (1 - q(x))*(1-q(x)*q(x)*q(x)*.95*.95*.95)/(1-q(x)*.95)
 j99(x) = (1 - q(x))*(1-q(x)*q(x)*q(x)*.99*.99*.99)/(1-q(x)*.99)
 j999(x) = (1 - q(x))*(1-q(x)*q(x)*q(x)*.999*.999*.999)/(1-q(x)*.999)

set term postscript

plot [0:20] [1e-10:1] 1-h(x) title "Single Version(E/3)", 1-j90(x) title "RB Cov. =.90", 1-j95(x) title "RB Cov. =.95",  1-j99(x) title "RB Cov. =.99",  1-j999(x) title "RB Cov. =.999",  1-j50(x) title "RB Cov. =.50"