As shown in the reproducible example below, I used the RStudio function haven()
to read a Stata .dta file, and then tried to do some fitting with the resulting
data.frame. This produced an error from my fitting function rqss() in the
package quantreg. After a bit of frustrated cursing, I converted the
data.frame, D, to a matrix A, and thence back to a data.frame B, and tried
again, which worked as expected. The conversion removed the attributes of D.
My question is: why were the attributes inhibiting the fitting?
In accordance with the usual R-help etiquette I first tried to contact the
maintainer of the haven package, i.e. RStudio, which elicited the response:
"since the error is occurring outside RStudio we’re not responsible, so try
Stack Overflow". This is pretty much what I would have expected from the
capitalist running dogs they are. Admittedly, the error is probably due to
some unforeseen infelicity in my rqss() coding, but it does seem odd that
attributes could have such a drastic effect. I would be most grateful for any
insight the R commune might offer.
#require(haven) # for reading dta file
#Ddta <- read_dta(“foo.dta")
#D <- with(Ddta, data.frame(y = access_merg, x = meannets_allhh, z = meanhh))
#save(D, file = "D.Rda")
con <- url("http://www.econ.uiuc.edu/~roger/research/data/D.Rda";)
load(con)
# If I purge the Stata attributes in D:
A <- as.matrix(D)
B <- as.data.frame(A)
# This works:
with(D,plot(x, y, cex = .5, col = "grey"))
taus <- 1:4/5
require(quantreg)
for(i in 1:length(taus)){
f <- rqss(y ~ qss(x, constraint = "I", lambda = 1), tau = taus[i], data = B)
plot(f, add = TRUE, col = i)
}
# However, the same code with data = D, does not. Why?
______________________________________________
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.
