[R] Scan and Lists

Francisco J. Zagmutt gerifalte28 at hotmail.com
Thu Sep 15 01:45:08 CEST 2005


Hi Michael

An example of your list would have helped.  Anyhow, why do you want to read 
a list? If you created a list object in R and want to save it and then read 
it back in other session or in some other time a good option is to write an 
ASCII representation of the object using dput and then recreate it using 
dget i.e.

mylist= list(x=cars[,1], y=cars[,2])
dput(mylist,"mylist")
mylistback=dget("mylist")
$x
[1]  4  4  7  7  8  9 10 10 10 11 11 12 12 12 12 13 13 13 13 14 14 14 14 15 
15
[26] 15 16 16 17 17 17 18 18 18 18 19 19 19 20 20 20 20 20 22 23 24 24 24 24 
25

$y
[1]   2  10   4  22  16  10  18  26  34  17  28  14  20  24  28  26  34  34  
46
[20]  26  36  60  80  20  26  54  32  40  32  40  50  42  56  76  84  36  46 
  68
[39]  32  48  52  56  64  66  54  70  92  93 120  85

If you want to read some other type of data take a look at the higher lever 
functions listed under ?read.table and the functions at 
library(help="foreign")

I hope this helps

Francisco

PS: Nasty weather in Fort Collins today!

>From: Michael Lefsky <lefsky at gmail.com>
>Reply-To: lefsky at gmail.com
>To: r-help at stat.math.ethz.ch
>Subject: [R] Scan and Lists
>Date: Wed, 14 Sep 2005 15:06:17 -0600
>
>This may be a newbie question - although I did search for this error
>message in the archives and via google and didn't see this error:
>
>The help page for "scan" indicates that among the types of data
>capable of being read are:
>
> > "The supported types are 'logical', 'integer', 'numeric', 'complex', 
>'character', 'raw' and 'list':
> > 'list' values should have elements which are one of the first six types 
>listed or 'NULL'.
>
>I have tried to use a list within a "what" list :
>
>f <- 
>scan(file="c:/test/testout.csv",what=list(hi=0.0,bye="",wave=list(1:1000)),sep=",",skip=1)
>
>and the following error is returned:
>
>  "c:/test/testout.csv", what = list(hi = 0, bye = "",  :
>         unimplemented type 'list' in 'extractItem'
>
>So, is my syntax confusing R, or is the documentation wrong, or is it
>some other, third, option?
>
>Thanks
>
>M
>--
>Michael Lefsky
>College of Natural Resources
>Colorado State University
>---------------------------------------------------------------------
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