pdfZ=\(z) integrate(\(x) incu(x)*wind(x-z),0,Inf)$value pdfZ=Vectorize(pdfZ) curve(pdfZ,-10,10,xlab='incubation-window (days)',axes=F,ylab='') ; axis(1) integrate(pdfZ,-Inf,0)$value fnr=\(x) integrate(pdfZ,-Inf,-x)$value # false negative rate after x days since onset of symtom fnr=Vectorize(fnr) curve(fnr,0,7, xlab='days after onset',ylab='false negative rate')
## k=1e5 inc=rlnorm(k,m=1.64,s=0.58) win=rweibull(k,shape=2.5,scale=4.5) d=inc-win hist(d) mean(inc) mean(win) mean(inc<win) # negative test re=NULL for(i in 1:7) re=c(re,mean((inc+i)<win)) ; re plot(re,pch=16) which(re<0.05)[1]