Hi Ivo,
Good to hear from you.
On Wednesday, February 10, 2016 at 9:58:37 AM UTC-6, ivo welch wrote:
>
>
> ladies and gents---I am not (yet) a julia user.
>
> may I suggest adding more examples into two places where julia users will
> face starting hurdles?
>
> [1] the I/O docs of julia. like, reading and writing csv files that are
> compressed and decompressed on-the-fly, even if not in the ultimate
> efficient manner. a large fraction of the time and frustration of new
> users is consumed by the task of shoehorning data into and out of new
> computer languages. with all of R's problem, the ' d <- read.csv("f.csv")'
> and 'd<-read.csv(pipe(paste("gzcat ", fname)))' reduced this entry
> frustration greatly. perhaps xml file reading and writing. perhaps...
>
> [2] more 'standard task' programs would be great. read a csv file, run a
> regression according to variable names on the command line, print output,
> draw a graph. I know there are fragments throughout the docs, but some
> section with ready to run complete programs would be good, perhaps at the
> end of the manual.
>
> in a year, I hope to switch my students from R to julia.
>
My main use of the RCall package is to import datasets from R into Julia.
If I have a dataset in an R package I use, e.g.
julia> using RCall
julia> ds = rcopy("lme4::Dyestuff")
30x2 DataFrames.DataFrame
| Row | Batch | Yield |
|-----|-------|--------|
| 1 | "A" | 1545.0 |
| 2 | "A" | 1440.0 |
| 3 | "A" | 1440.0 |
| 4 | "A" | 1520.0 |
| 5 | "A" | 1580.0 |
| 6 | "B" | 1540.0 |
| 7 | "B" | 1555.0 |
| 8 | "B" | 1490.0 |
| 9 | "B" | 1560.0 |
| 10 | "B" | 1495.0 |
| 11 | "C" | 1595.0 |
| 12 | "C" | 1550.0 |
| 13 | "C" | 1605.0 |
| 14 | "C" | 1510.0 |
| 15 | "C" | 1560.0 |
| 16 | "D" | 1445.0 |
| 17 | "D" | 1440.0 |
| 18 | "D" | 1595.0 |
| 19 | "D" | 1465.0 |
| 20 | "D" | 1545.0 |
| 21 | "E" | 1595.0 |
| 22 | "E" | 1630.0 |
| 23 | "E" | 1515.0 |
| 24 | "E" | 1635.0 |
| 25 | "E" | 1625.0 |
| 26 | "F" | 1520.0 |
| 27 | "F" | 1455.0 |
| 28 | "F" | 1450.0 |
| 29 | "F" | 1480.0 |
| 30 | "F" | 1445.0 |
If I wanted to read a CSV file using the facilities in R I could use
julia> rcopy("read.csv('/usr/share/distro-info/debian.csv')")
17x6 DataFrames.DataFrame
| Row | version | codename | series | created | release
| eol |
|-----|---------|----------------|----------------|--------------|--------------|--------------|
| 1 | 1.1 | "Buzz" | "buzz" | "1993-08-16" |
"1996-06-17" | "1997-06-05" |
| 2 | 1.2 | "Rex" | "rex" | "1996-06-17" |
"1996-12-12" | "1998-06-05" |
| 3 | 1.3 | "Bo" | "bo" | "1996-12-12" |
"1997-06-05" | "1999-03-09" |
| 4 | 2.0 | "Hamm" | "hamm" | "1997-06-05" |
"1998-07-24" | "2000-03-09" |
| 5 | 2.1 | "Slink" | "slink" | "1998-07-24" |
"1999-03-09" | "2000-10-30" |
| 6 | 2.2 | "Potato" | "potato" | "1999-03-09" |
"2000-08-15" | "2003-07-30" |
| 7 | 3.0 | "Woody" | "woody" | "2000-08-15" |
"2002-07-19" | "2006-06-30" |
| 8 | 3.1 | "Sarge" | "sarge" | "2002-07-19" |
"2005-06-06" | "2008-03-30" |
| 9 | 4.0 | "Etch" | "etch" | "2005-06-06" |
"2007-04-08" | "2010-02-15" |
| 10 | 5.0 | "Lenny" | "lenny" | "2007-04-08" |
"2009-02-14" | "2012-02-06" |
| 11 | 6.0 | "Squeeze" | "squeeze" | "2009-02-14" |
"2011-02-06" | "2014-05-31" |
| 12 | 7.0 | "Wheezy" | "wheezy" | "2011-02-06" |
"2013-05-04" | "" |
| 13 | 8.0 | "Jessie" | "jessie" | "2013-05-04" |
"2015-04-25" | "" |
| 14 | 9.0 | "Stretch" | "stretch" | "2015-04-25" | ""
| "" |
| 15 | 10.0 | "Buster" | "buster" | "2018-07-01" | ""
| "" |
| 16 | NA | "Sid" | "sid" | "1993-08-16" | ""
| "" |
| 17 | NA | "Experimental" | "experimental" | "1993-08-16" | ""
| "" |
(It turns out that R's allowing either ' or " for enclosing strings is an
advantage for quoting strings within strings.)
