zest <- data.frame(
z1=c(0.27,0.18,0.56,0.61,0.09,0.27,0.96,0.34,0.69,0.13),
z2=c(0,0,0,0,0,0,0,0,0,0)
)
zest$z2=1-zest$z1

compare <- data.frame(
verite=c('N','N','N','N','O','O','O','O','O','O'),
decision=c('N','N','N','N','O','O','O','O','O','O')
)

TFP <- TVP <- NULL
for (ii in 1:9)
{	
compare$decision[zest$z2>ii/10]='N'
compare$decision[zest$z2<=ii/10]='O'
confusion <- table(compare)
TFP[ii]=confusion[2,1]/(confusion[2,1]+confusion[2,2])
TVP[ii]=confusion[1,1]/(confusion[1,1]+confusion[1,2])
print(confusion)
print(TFP[ii])
print(TVP[ii])
}

plot(TFP,TVP,'b',xlab='TFP',ylab='TVP')