Dear all, I'm trying to fit the following function
slope_pp3_mrna = ( (k3 * v3_K_d *p1^v3_h) / ( (v3_Kd^v3_h) + p2^v3_h ) ) * ( 1/(1 + (p2/v4_Kd)^v4_h) ) - pp3_mrna to this experimental data in the datafraeme "Data_pp3_mrna" (see it at the end of this e-mail) I'm using the nls function in the following code. IN the last step of the fit "fm_pp3_mrna_4", when I add to the funziont the paramter v4_Kd something goes wrong, and I reeive this message Error in numericDeriv(form[[3L]], names(ind), env) : Missing value or an infinity produced when evaluating the model What could be the error? I tried with differnet intial values of v4_Kd, but I did not fix the problem. Here below the code. Thanks in advance, Paola. Data_pp3_mrna <- data.frame( p1 = protein_1, p2 = protein_2, pp3_mrna = protein_3_mrna, slope_pp3_mrna = stinemanSlopes(times, protein_3_mrna) ) one_par <- nls(slope_pp3_mrna ~ ( (k3 * p1) / ( (1) + p1 ) ) * ( 1/(1 + (p2)) ) - pp3_mrna, data=Data_pp3_mrna, start=list( k3=0.1 )) summary(one_par) fm_pp3_mrna_1 <- nls(slope_pp3_mrna ~ ((k3 * v3_Kd *p1) / ( (v3_Kd) + p1 ) ) * ( 1/(1 + (p2)) ) - pp3_mrna, data=Data_pp3_mrna, start=list(k3=24, v3_Kd=1 )) summary(fm_pp3_mrna_1) fm_pp3_mrna_2 <- nls(slope_pp3_mrna ~ ((k3 * v3_Kd *p1^v3_h) / ( (v3_Kd)^v3_h + p1^v3_h ) ) * ( 1/(1 + (p2)) ) - pp3_mrna, control = list(maxiter = 500), data=Data_pp3_mrna, start=list(k3=69, v3_Kd=0.3238, v3_h=1 )) summary(fm_pp3_mrna_2) fm_pp3_mrna_3 <- nls(slope_pp3_mrna ~ ((k3 * v3_Kd *p1^v3_h) / ( (v3_Kd)^v3_h + p1^v3_h ) ) * ( 1/(1 + (p2)^v4_h) ) - pp3_mrna, control = list(maxiter = 500), data=Data_pp3_mrna, start=list(k3=37.451, v3_Kd=0.59, v3_h=2.013, v4_h=0.000001 )) summary(fm_pp3_mrna_3) fm_pp3_mrna_4 <- nls(slope_pp3_mrna ~ ((k3 * v3_Kd *p1^v3_h) / ( (v3_Kd)^v3_h + p1^v3_h ) ) * ( 1/(1 + (p2/v4_Kd)^v4_h) ) - pp3_mrna, control = list(maxiter = 500), data=Data_pp3_mrna, start=list(k3=56.2823, v3_Kd=0.3366, v3_h=1.8040, v4_Kd=0.03, v4_h=0.7693 )) Here the data. > Data_pp3_mrna p1 p2 pp3_mrna slope_pp3_mrna 1 1.006 0.921 0.0410000 8.63741887 2 2.235 2.047 2.9069031 2.82619343 3 3.744 3.937 4.0520000 0.84354113 4 4.222 9.340 4.3237353 0.47577213 5 9.022 14.609 4.5310000 -0.03940131 6 11.326 22.765 3.5100000 -2.04200000 7 6.899 17.852 2.4890000 -1.86822481 8 10.709 27.777 1.6222048 -1.55625973 9 14.084 27.785 0.9110000 -0.48800514 10 14.922 23.613 0.8260000 -0.17000000 11 14.340 18.422 0.7410000 -0.22560156 12 13.066 24.085 0.5990000 -0.28400000 13 17.553 18.594 0.4570000 -0.13847372 14 14.803 16.831 0.4550965 0.03588624 15 11.945 14.495 0.4930000 0.09536674 16 11.427 12.458 0.5505361 0.15549062 17 11.556 9.082 0.6490000 0.49638596 18 20.107 9.987 1.2486525 1.36871828 19 15.999 10.305 2.0590000 1.87868197 20 16.094 5.793 3.2285000 2.33900000 21 11.752 6.944 4.3980000 0.80395869 22 15.841 5.575 4.6510000 0.50600000 23 12.601 5.221 4.9040000 0.80270128 24 13.598 2.872 5.8190000 1.83000000 25 13.879 2.883 6.7340000 -0.03571884 26 16.270 2.213 6.4135000 -0.64100000 27 17.176 3.381 6.0930000 -0.33913760 28 12.332 2.781 6.0320000 -0.12200000 29 12.373 3.073 5.9710000 -0.41224459 30 14.781 2.948 5.4890000 -0.96400000 31 17.578 3.953 5.0070000 -0.68258311 32 18.865 2.279 4.7568901 -0.39425557 33 14.735 2.806 4.6060000 0.13264481 34 16.160 1.676 4.9870000 0.76200000 35 13.416 2.478 5.3680000 0.63914248 36 13.864 1.394 5.6374239 0.45419096 37 16.219 2.299 5.8270000 -0.12540453 38 13.249 1.457 5.2505000 -1.15300000 39 14.445 2.325 4.6740000 -0.09880849 40 13.210 2.230 5.5576966 2.17200142 41 12.358 2.116 8.9470000 11.38521228 -- *Paola Lecca, PhD* *The Microsoft Research - University of Trento* *Centre for Computational and Systems Biology* *Piazza Manci 17 38123 Povo/Trento, Italy* *Phome: +39 0461282843* *Fax: +39 0461282814* [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.