Re: [R] Scan and Lists
Michael == Michael Lefsky [EMAIL PROTECTED]
on Wed, 14 Sep 2005 15:06:17 -0600 writes:
Michael This may be a newbie question - although I did
Michael search for this error message in the archives and
Michael via google and didn't see this error:
I know how useful google can be - - still, sometimes one would
better spend the time differently ... You know the old IBM
motto? If not, google for IBM motto ;-)
Michael The help page for scan indicates that among the types of data
Michael 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'.
Michael I have tried to use a list within a what list :
which was wrong:
Michael f - scan(file=c:/test/testout.csv,
Michael what=list(hi=0.0,bye=,wave=list(1:1000)),
Michael sep=,,skip=1)
Michael and the following error is returned:
Michael c:/test/testout.csv, what = list(hi = 0, bye = , :
Michael unimplemented type 'list' in 'extractItem'
Michael So, is my syntax confusing R, or is the documentation wrong, or is
it
Michael some other, third, option?
3rd: You didn't read the documentation carefully enough
(though I agree that the current wording leaves a non-small
possibility for confusion):
In your above citation from the help page, you've left off
crucial context. Here is a bit more
what: the type of 'what' gives the type of data to be read. If
'what' is a list, it is assumed that the lines of the data
file are records each containing 'length(what)' items
(fields). 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'.
So 'what' has a *type* and that type can be logical, , and list.
where list should have elements from the first six types ---
which do *NOT* include list.
In short: It does exclude using a *list* inside the list.
Is your data
double character int int int
with 1000 integers, i.e. you have 1002 columns?
If yes, you'd probably get what you want by
whatCols - c(list(hi=0.0, bye=), as.list(1:1000))
f - scan(file = c:/test/testout.csv,
what = whatCols, sep= ,, skip=1)
{The point here is that c(l1, l2) is used to concatenate two
lists l1 and l2;
and yes: Please do use spaces {and indentation} to make your
more readable !
}
Michael Thanks
You're welcome,
Martin Maechler, ETH Zurich
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[R] Scan and Lists
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 - Out of the crooked timber of humanity, no straight thing was ever made- Immanuel Kant __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] Scan and Lists
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 [EMAIL PROTECTED] Reply-To: [EMAIL PROTECTED] To: r-help@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 - Out of the crooked timber of humanity, no straight thing was ever made- Immanuel Kant __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
