>>953

> pLR=0.7/0.3 #TP/FP
> nLR=0.3/0.7 #FN/TN
> pOdds=1/999*pLR
> nOdds=1/999*nLR
> ppv=pOdds/(1+pOdds) ; ppv
[1] 0.002330226
> npv=1-nOdds/(1+nOdds) ;npv
[1] 0.9995712