[R] Extracting an object name?

greggallen at gmail.com greggallen at gmail.com
Sat Apr 25 03:30:30 CEST 2009


Dear Sir or Madam:

This is an extension to a earlier post, about looping through several
thousand files, and testing student's models against a different
data-set, called rclnow, for "recall now".

The problem is, that the instructor never specified to the students,
what they should name their "lm" object.

So what they created was:
"arbitrary variable name" <- lm(Y~(V1+V2+.... more stuff), learn_data_frame)

Now there are 1500+ files that are named:
"BIOtotals_students_name_class_name_date_other_info..."
"BIOtotals_more_stuff_2.."
"BIOtotal_more-stuff_3
......................
......................


Now I always get this error in the "predict" statement:

Error in UseMethod("predict") : no applicable method for "predict"

Is there a way to pass the unknown object name to predict, or do we
need to ask the students to redo all the work with a given model name?
(I hope not!)


function(L)
{
fname <- format(Sys.time(), 'Totals_%b%d_%H%M_%S.txt')
filesused <- format(Sys.time(), 'Files_%b%d_%H%M_%S.txt')
setwd("/Users/gregg/R_system")
dire <- getwd()
print(dire)
flies <- list.files(pattern = "BIOtotal*")# flies instead of files
because of FEAR of reserved words!!!
for(i in 1:length(flies))
{
s <-   flies[i]
print(i) # print everything for debugging
print(s)
model <- load(s)
print(model)
z  <- predict( model ,rclnow) ##############  what will model be?????
print(z)
write( z, fname   , append = TRUE,  ncolumns = L)
write( as.character(s) , filesused   , append = TRUE,  ncolumns = 1 )
}
}


THANKS for any help!

Greg Allen




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