On Feb 27, 2010, at 11:47 AM, Balzer Susanne wrote:
Hei David,
Thanks for your quick response, but unfortunately n and nmax alone
don't do the job. If I want to read items no. 100001 to 200000, the
n=100000 option will work, but skip=100000 (to NOT read the first
100000 items) won't.
Or with your example,
scan(textConnection('1 2 3 4 5 6 7'), skip=3) will never work, while
True.
scan(textConnection('1 2 3 4 \n 5 \n 6 \n 7'), skip=3) will. But I
don't have line breaks in my file.
Right. That was what I was trying to help you deal with.
Is there no way to specify the character for a line break in scan /
read.table / etc.?
Why are you fixating on linefeeds when you don't have any?????
> closeAllConnections()
> tc <- textConnection(paste(1:100, sep=" ", collapse=" "))
> scan(tc, nmax=10)
Read 10 items
[1] 1 2 3 4 5 6 7 8 9 10
> scan(tc, nmax=10)
Read 10 items
[1] 11 12 13 14 15 16 17 18 19 20
> scan(tc, nmax=10)
Read 10 items
[1] 21 22 23 24 25 26 27 28 29 30
> scan(tc, nmax=10)
Read 10 items
[1] 31 32 33 34 35 36 37 38 39 40
> scan(tc, nmax=10)
Read 10 items
[1] 41 42 43 44 45 46 47 48 49 50
> scan(tc, nmax=10)
Read 10 items
[1] 51 52 53 54 55 56 57 58 59 60
> scan(tc, nmax=10)
Read 10 items
[1] 61 62 63 64 65 66 67 68 69 70
> scan(tc, nmax=10)
Read 10 items
[1] 71 72 73 74 75 76 77 78 79 80
> scan(tc, nmax=10)
Read 10 items
[1] 81 82 83 84 85 86 87 88 89 90
> scan(tc, nmax=10)
Read 10 items
[1] 91 92 93 94 95 96 97 98 99 100
> scan(tc, nmax=10)
Read 0 items
numeric(0)
--
David.
Kind regards,
Susanne
-----Opprinnelig melding-----
Fra: David Winsemius [mailto:dwinsem...@comcast.net]
Sendt: 27. februar 2010 17:38
Til: Balzer Susanne
Kopi: 'r-help@r-project.org'
Emne: Re: [R] scan and skip - without line breaks in the input file
On Feb 27, 2010, at 11:24 AM, Balzer Susanne wrote:
Dear all,
I am trying to read in big amounts of data with scan. It's only one
variable, numeric values, separated by tabs,.. and it's many of
them. So I was thinking that I could use the skip option and read in
100000 values at a time - but skip doesn't work, probably because I
don't have line breaks in the txt file. So any value specified for
skip makes the scan function jump to the end of the file.
?scan
Without a working example it is hard to be sure, but it appears from a
rapid look at the help page that nmax is the argument you want.
scan(textConnection('1 2 3 4 5 6 7'), nmax=4)
Read 4 items
[1] 1 2 3 4
(Ignores line-feeds)
scan(textConnection('1 2 \n 3 4 5 6 7'), nmax=4)
Read 4 items
[1] 1 2 3 4
--
David.
Does anyone have a good idea? I would be extremely grateful.
Kind regards,
Susanne Balzer
****************************
Susanne Balzer
PhD Student
Institute of Marine Research
N-5073 Bergen, Norway
Phone: +47 55 23 69 45
susanne.bal...@imr.no
www.imr.no
______________________________________________
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
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David Winsemius, MD
Heritage Laboratories
West Hartford, CT
David Winsemius, MD
Heritage Laboratories
West Hartford, CT
______________________________________________
R-help@r-project.org mailing list
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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.
