[R] Data Frame Manipulation using function

Erik Iverson eriki at ccbr.umn.edu
Fri Jul 9 03:43:55 CEST 2010


It will be a lot easier to help you if you follow the posting guide and PLEASE 
do read the posting guide and provide commented, minimal, self-contained, 
reproducible code.

You gave your function definition, which is good.  Use ?dput to give us a small 
data.frame that can accurately show what you want.


harsh yadav wrote:
> Hi all,
> 
> I have a data frame for which I want to limit the output by checking whether
> row values for specific column meets particular conditions.
> 
> Here are the more specific details:
> 
> I have a function that checks whether an input string exists in a defined
> list:-
> 
> checkBaseLine <- function(s){
>  for (listItem in WHITELIST){
> if(regexpr(as.character(listItem), s)[1] > -1){
>  return(TRUE)
> }
> }
>  return(FALSE)
> }
> 
> Now, I have a data frame for which I want to apply the above function for
> all row values for a given column:-
> 
> This works fine when I define a condition like:
> data <- data[data$urlType != 1,]
> 
> However, I want to combine two logical conditions together like:
> data <- data[data$urlType != 1 & checkBaseLine(data$url),]
> 
> This would check whether the column `urlType` contains row values that !=
> 1,
> and the column `url` contains row values that gets evaluated using the
> defined function.
> 
> Any ideas how this can be done?
> 
> Thanks in advance.
> 
> Regards,
> Harsh Yadav
> 
> 	[[alternative HTML version deleted]]
> 
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> and provide commented, minimal, self-contained, reproducible code.



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