[R] Read fst files

Bill Dunlap w||||@mwdun|@p @end|ng |rom gm@||@com
Wed Jun 9 20:43:11 CEST 2021


Try using unzip(zipfile, files="desiredFile", exdir=tf<-tempfile()), not
unz(zipfile, "desiredFile"), to copy the desired file from the zip file to
a temporary location and use read_fst(tf) to read the desired file.

-Bill

On Wed, Jun 9, 2021 at 11:27 AM Jeff Reichman <reichmanj using sbcglobal.net>
wrote:

> Jan
>
> Makes sense. Its just that I often receive  large zip files that contain a
> variety of file types.
>
> Jef
>
> -----Original Message-----
> From: R-help <r-help-bounces using r-project.org> On Behalf Of Jan van der Laan
> Sent: Wednesday, June 9, 2021 12:56 PM
> To: r-help using r-project.org
> Subject: Re: [R] Read fst files
>
>
>
> read_fst is from the package fst. The fileformat fst uses is a binary
> format designed to be fast readable. It is a column  oriented format and
> compressed. So, to be able to work fst needs access to the file itself
> and wont accept a file connection as functions like read.table an
> variants accept.
>
> Also, because it is a binary compressed format using a compression
> method that is fast to read, compressing also to zip seems to defeat the
> purpose of fst.
>
> HTH,
> Jan
>
>
> On 09-06-2021 15:28, Duncan Murdoch wrote:
> > On 09/06/2021 9:12 a.m., Jeff Reichman wrote:
> >> Duncan
> >>
> >> Yea that will work. It appears to be related to setting my working
> >> dir, for what ever reason neither seem to work
> >> (1) knitr::opts_knit$set(root.dir
> >> ="~/My_Reference_Library/Regression") # from R Notebook or
> >> (2)
> >> setwd("C:/Users/reichmaj/Documents/My_Reference_Library/Regression") #
> >> from R chunk
> >>
> >> So it appears I can either (as you suggested) use two steps or combine
> >> but I need to enter the full path. Why other file types don't seem to
> >> need the full path ....?????
> >
> > You need to read the documentation for read_fst() to find what it needs.
> >   If it doesn't explain this, then you should report the issue to its
> > author.
> >
> >>
> >> myObject <-
> >>
> read_fst(unz("C:/Users/reichmaj/Documents/My_Reference_Library/Regression/Datasest.zip",
>
> >> filename = "myFile.fst"))
> >>
> >> Thank you. I guess just one of those R things
> >
> > No, it's a read_fst() thing.
> >
> > Duncan Murdoch
> >
> > ______________________________________________
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> > PLEASE do read the posting guide
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> > and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
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> 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.
>

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