[R] Some questions about string processing

[Phil Spector]

Michael -
    You're doing too much work half the time, and not enough
the other half :-).  Try this (untested):

auto_io = function(data_name,factors){
    resp_data =  read.table(data_name, header = TRUE )
    temp_model = lm(formula(paste('y',factors,sep='~')) data = resp_data )
                . . .

 					- Phil Spector
 					 Statistical Computing Facility
 					 Department of Statistics
 					 UC Berkeley
 					 spector at stat.berkeley.edu


On Fri, 24 Sep 2010, Michael Hopkins wrote:

>
>
> Hi all
>
> A couple of questions about string processing from someone who has only scratched the surface so far.
>
> 1) I am wanting to send some strings into a function to allow flexibility inside.  My first idea has been e.g.
>
> auto_io <- function( var_string, factors ) {
> #  e.g. var_string sent as "test_file.txt"  factors sent as "x1 + x2 + x3"
>
> # input
> 	data_name 				<- get( var_string )
>
> #	term_list 				<- get( factors )
>
> 	resp_data 				<- read.table( data_name, header = TRUE )
>
> # fit
> 	temp_model 			<-  lm( y ~ factors, data = resp_data )
>
> 	etc...
>
> Neither the read.table() nor the lm() are working because in each case the string is not converted or understood properly.  I'm sure this is possible (and in fact probably easy) but haven't yet seen the light.  Could someone illuminate me here?
>
> 2) I will be wanting to process strings as lists of strings.  For instance, I might instead want to send factors above as "x1  x2  x3" and add the "+" when I need them, or perhaps "*" instead, and also look at sub-models by removing parts of the string etc.  What functions should I be looking at here and are there any examples available?
>
> Thanks in advance.  Feel free to CC me on your reply.
>
>
> Michael Hopkins
> Algorithm and Statistical Modelling Expert
>
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