Veronesi, Fabio wrote:
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"
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?
Not automatically, but you can write an expression to do that:
if (exists("MAD4")) MAD4 else NA
or
tryCatch(MAD4, error=function(e) NA)
You could write a function to do this. I wouldn't recommend trying the
first version; it will be messy. But the second is:
defaultNA <- function(x) {
tryCatch(x, error=function(e) NA)
}
then defaultNA(MAD4) will do what you want.
Duncan Murdoch
______________________________________________
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.
