hi doug---and vice-versa. it's interesting that a core function (reading a .csv file) would not be in a native julia library. when are you switching your students to julia? regards, /iaw
---- Ivo Welch ([email protected]) http://www.ivo-welch.info/ J. Fred Weston Distinguished Professor of Finance Anderson School at UCLA, C519 Free Finance Textbook, http://book.ivo-welch.info/ Exec Editor, Critical Finance Review, http://www.critical-finance-review.org/ Editor and Publisher, FAMe, http://www.fame-jagazine.com/ On Thu, Feb 11, 2016 at 12:37 PM, Douglas Bates <[email protected]> wrote: > 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.) >
