[R] Batch mode questions.

[David Winsemius]

> On Jul 25, 2018, at 2:54 PM, Rich Shepard <rshepard using appl-ecosys.com> wrote:
> 
> On Wed, 25 Jul 2018, Shawn Way wrote:
> 
>> To get you start, here's a script I used to combine any number of files
>> into one data.frame.
>> 
>> library(knitr)
>> library(tidyverse)
>> library(xlsx)
>> library(xtable)
>> library(lubridate)
>> 
>> # create a list from these files
>> list.filenames<-list.files(pattern=".CSV$")  # This gets a list of all CSV files

It would get all the files with all caps "CSV" anywhere within the file name, but it would not get any files with an extension ".csv", nor would it exclude a file named "somethingCSV" . The pattern argument is interpreted as a regex pattern and the meaning of a period is different.

Better for this purpose would be:

list.files(pattern="\\.(csv|CSV)$")

I suppose this criticism might be platform-specific if the filesystem were caps-agnostic, but mine is not.

-- 
David.

>> 
>> data <- list.filenames %>%
>>   map(read_csv) %>%  # This reads all the files in order
>>   reduce(rbind)   # This combines the data into one data frame
> 
>  Thanks, Shawn. I'm reading up on functions and will look at using a
> function within either a Rscript or source'd script.
> 
>  It's about time I learn to automate repeated, tedious tasks in R.
> 
> Much appreciated,
> 
> Rich
> 
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David Winsemius
Alameda, CA, USA

'Any technology distinguishable from magic is insufficiently advanced.'   -Gehm's Corollary to Clarke's Third Law