Hi
r-help-boun...@r-project.org napsal dne 04.12.2009 12:09:08: > Hi everybody, > I'm trying to create a script that picks a txt file with 2 columns of > coordinates (depth and variable1) and automatically tries to fit several > polynomial with the function nls(). > After that, it creates a list of observed, predict, residuals and other, and > then it calculates AIC, RMSD, MAD and R^2. > At the end of the script I create a series of vectors with MAD for all > polynomials, RMSD for all polynomial and so on, and from a matrix a .csv file. > This script is completely automatic, but there is a problem if one or more > models don't fit, because if one or more data is missing I cannot create the > vectors and the matrix, as well. > > So, my question is: is it possible to create a vector with a missing object, > substituting that object with NA in the vector? > > For example: > I want to create this vector > Vec1<-c(MAD1,MAD2,MAD3,MAD4) > but MAD4 is missing and as a consequence R return an error like this: > "object 'MAD4' not found" Look at ?try function. I did something similar #this is just a selection if inputed start values shall be used fit<-try(nls(formula[[i]], data, ...)) } else { fit<-try(nls(formula[[i]], data, start, ...)) } } #here is a test whether fit had some result, if yes values are extracted from fit if not, NA is put into list if( class(fit)=="try-error") result1[i] <- NA else result1[i] <- sum(resid(fit)^2, na.rm=T) if( class(fit)=="try-error") result2[[i]] <- NA else result2[[i]] <- coef(fit) } Regards Petr > > Is it possible to say to R that if it does not find an object it must > substitute that object with NA in the vector? > > Many Thanks, Fabio > > > Mr. Fabio Veronesi > Ph.D. student > > Cranfield University, Bld.37 > School of Applied Sciences > MK43 0AL > Cranfield, Bedfordshire > > Tel. +44 (0)7984049316 > e-mail: f.veron...@cranfield.ac.uk > > [[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. ______________________________________________ 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.