Extracting an object name?
On Apr 24, 2009, at 9:30 PM, greggallen at gmail.com wrote:
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)
That would have created an object, but would not have determined what it would be called on the disk when it was saved.
Now there are 1500+ files that are named: "BIOtotals_students_name_class_name_date_other_info..." "BIOtotals_more_stuff_2.." "BIOtotal_more-stuff_3 ...................... ......................
Right, but you do not know what the names of the models will be when they are loaded.
Now I always get this error in the "predict" statement:
Error in UseMethod("predict") : no applicable method for "predict"
Perhaps because you have not named the object properly?
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!)
Can set up the workspace so that you assign the only lm object to a standardized name and then operate on that name?
function(L) ### what is 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)
Probably need to lapply(flies, load) and let them be named whatever they are named
print(model)
Probably now need to look at the workspace with ls(...) and somehow get the names of all the objects of class lm. Then lapply a predict function tomembers of that list
z <- predict( model ,rclnow) ############## what will model be????? #see above
How will you know whose model is which, ... do do you care?
print(z) write( z, fname , append = TRUE, ncolumns = L) write( as.character(s) , filesused , append = TRUE, ncolumns = 1 ) } }
David Winsemius, MD Heritage Laboratories West Hartford, CT