stephenxqy wrote > > It is a complex function, functions are quoted frequently, you may read > from bottom up > The independent variable for final fit is q > > %%Rg0 is a function of L and b > Rg0sq<-function(L,b)L*b/6*(1-3/2*b/L+3/2*(b/L)^2-3/4*(b/L)^3*(1-exp(-2*L/b))) > > %%alpha is a defined function > alpha<-function(x)(1+(x/3.12)^2+(x/8.67)^3)^(0.176/3) > > %%w is a defined function > w<-function(x)(1+tanh(x-1.523)/0.1477)/2 > > %%It is Rg^2 > Rgsq<-function(L,b)(alpha(L/b)*Rg0sq(L,b)) > > %%This is Rg > Rg<-function(L,b)(Rg0sq(L,b))^0.5 > > %%A debye function of q, the parameters are L and b > PDebye<-function(L,b)2*(exp(-q^2*Rg0sq(L,b))+q^2*Rg0sq(L,b)-1)/q^4/(Rg0sq(L,b))^2 > > %%Another function of q that quote w, PDebye, Rg, parameters are v, L and > b > Pexv<-function(v,L,b)w(q*Rg(L,b))*PDebye(L,b)+(1-w(q*Rg(L,b)))(1.22*(q*Rg(L,b))^(-1/v)+0.4288*(q*Rg(L,b))^(-2/v)-1.651*(q*Rg(L,b))^(-1/v)) > > %%Another defined function > cf<-function(L,b,pa,pb)pa/(L/b)^pb > > %%A function of q, quote Pexv, Rgsq, cf > Psfcex<-function(v,L,b,pa,pb)Pexv(v,L,b)+cf(L,b,pa,pb)*b/L/15*(4+7/q^2/Rgsq(L,b)-(11+7/q^2/Rgsq(L,b))*exp(-q^2*Rgsq(L,b))) > > %%non-linear fit > Pfit<-function(p)sum((I-Psfcex(p[1],p[2],p[3],p[4],p[5]))^2) > wavefit<-nlm(Pfit,c(1.5,500,5,1,0.1),hessian=TRUE) > > error code: Error in c(1.5, 500, 5, 1, 0.1) : unused argument(s) (0.1) > the fifth parameter is pb, which goes from Psfcex to cf, actually pa which > only exist in cf is used, why not pb? >
1. What language is this? # starts a comment line in R not %%. 2. no data for q 3. what is I in Pfit? 4. Pexv: missing * or + or ... The expression in the function Pexv should probably read w(q*Rg(L,b))*PDebye(L,b)+(1-w(q*Rg(L,b)))*(1.22*(q*Rg(L,b))^(-1/v)+0.4288*(q*Rg(L,b))^(-2/v)-1.651*(q*Rg(L,b))^(-1/v)) I have inserted * after (1-w(q*Rg(L,b))) assuming that is what you want. Your code is not reproducible since you have not provided data for q or I. Generating some random data and assuming I is an identity matrix with set.seed(123) q <- rnorm(20) + 5 I <- diag(length(q)) adding wavefit at the end of the script and changing the %% to # your script runs with no errors but with warnings. So I can't tell you why you get the error message you got. Finally: this is very inefficient code. There are repeated evaluations of same thing e.g. w(q*Rg(L,b)), Rg(L,b), Rg0sq(L,b) etc. Berend -- View this message in context: http://r.789695.n4.nabble.com/What-s-wrong-with-my-code-tp4640034p4640077.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
