[R] How to aggregate values in corresponding dataframes

[Rui Barradas]

Sorry, I forgot to ask something.

When you say you want to add the df's values, what exactly do you mean? 
All of the values, by row, by column, what?

Rui Barradas

Às 10:20 de 25/03/2019, Rui Barradas escreveu:
> Hello,
> 
> Maybe something like this?
> Note that you *never* need to set header = FALSE, it already is the 
> default of read.table. You would have to with read.csv.
> 
> 
> old_dir <- setwd("~/directory")
> f1990 <- list.files(pattern = "^199.*\\.txt$")
> r1990 <- lapply(f1990, read.table)
> setwd(old_dir)
> 
> 
> Hope this helps,
> 
> Rui Barradas
> 
> 
> Às 08:30 de 25/03/2019, lily li escreveu:
>> Hi R users,
>>
>> I have multiple dataframes in a directory, and with the same postfix
>> ".txt". Each dataframe is a gridded file with just values, but each value
>> represents one grid cell. There are many years, and each year has 12
>> months, so there are many such files. For each year, I want to read the
>> corresponding year's files and add the values of the dataframes, but I
>> don't know how to do that. For example, the file names are
>> 1990_file01.txt
>> 1990_file02.txt
>> ...
>> 1990_file12.txt
>> 1991_file01.txt
>> ...
>> 1991_file12.txt
>> ...
>>
>> And my code is like this:
>> f1990 = list.files("~/directory", pattern = "^1990(.*).txt$")
>> for(i in 1:length(f1990)){
>> r1990 = read.table(paste('~/directory',f1990[i],sep='/'),head=F)
>> }
>>
>> Could you provide some help on this? Thanks very much.
>>
>>     [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help using 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.
>>
> 
> ______________________________________________
> R-help using 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.