Hi everyone, I emailed yesterday thinking I had a problem with reading matrix information as numerical output into epiR. After working on the data frame today, I realise it's a problem with the data itself rather than the syntax. An original data frame of min max T1 1.500000e+01 3.999954e+01 SE1 0.000000e+00 1.000000e+00 PRE 0.000000e+00 1.000000e+00 WET 0.000000e+00 5.980000e+00 BE1 4.664642e+00 5.866620e+00 Kappa1 5.500000e+03 2.000000e+04 Kappa3 1.000000e+04 2.000000e+04 produces a latin hypercube sampling set called samplevalues: T1 SE1 PRE WET BE1 Kappa1 Kappa3 1 31.35590 0.7066388715 0.8665111432 4.965701530 5.783424 12240.019 12675.12 2 28.27640 0.5442730461 0.7000693454 3.181014435 5.183708 16626.566 10759.27 3 28.14695 0.6295741145 0.7818034368 2.262515130 4.670685 16930.360 13857.44 4 30.51873 0.3983581045 0.4026640041 2.730221171 5.058697 19546.625 14408.89 5 16.03162 0.0440886703 0.9954737808 1.002989298 5.310149 13188.279 19500.85 6 19.48413 0.4280443098 0.8500412067 1.668042962 5.068510 11742.748 18891.87 7 36.44783 0.5033961511 0.8249423312 5.582521574 4.722634 8738.121 16457.21 8 39.76318 0.8805976090 0.3430379347 4.876022801 4.787737 19873.134 18660.02 9 39.99782 0.4109272317 0.6606016486 0.191627831 5.625588 11086.803 13569.30 I have produced a column (r1) where each cell is a vector of the previous cells in that row. I tried binding them with zz<-cbind(samplevalues, r1) and then running epi<-epi.prcc(zz, sided.test=2) which is what produced the original error message of "Error in solve.default(C) : Lapack routine dgesv: system is exactly singular" I then tried 'sensitivity' with the syntax zz<-pcc(samplevalues, r1). I didn't get any error messages, but print(zz) only reveals the Call value, and no information. Any advice on what could be the problem?? thank you, Aimee Kopolow