FAQ Database Discussion Community


Grow a ffdf data frame on disk gradually

r,ff,ffbase
From documentation of save.ffdf: Using ‘save.ffdf’ automagically sets the ‘finalizer’s of the ‘ff’ vectors to ‘"close"’. This means that the data will be preserved on disk when the object is removed or the R sessions is closed. Data can be deleted either using ‘delete’ or by removing the directory where...

R - ff package : find the most frequent element in ffdf and delete the rows where is located

r,data.frame,ff,ffbase
I need a suggestion to find the most frequent element in ffdf and after that to delete the rows where is located. I decided to try the ff package as I'm working with very big data and with base R I am running out of memory. Here is a little...

How to DROP columns from ffdf object ? (R)

r,ff,ffbase
Could I easily drop column of ffdf object ? library(ff);library(ffbase) irisdf=as.ffdf(iris) How to contain only Sepal.length and Species columns ?...