If the records are always of the form:
number,"...","...",number
where ... may contain commas but not double quotes then here is a
kludgy solution. Perhaps its sufficient?
# scan in data using " as the delimiter and keep first and last fields
s <- scan("clipboard",skip=1,what=list("",NULL,NULL,NULL,""),sep="\"")
# remove commas from fields, convert to numeric and reshape into matrix
matrix(as.numeric(sub(",","",unlist(s))),nc=2)
--- Paul Bayer <[EMAIL PROTECTED]> wrote:
>Dear R-helpers,
>
>I have to read some large csv-files into R (30 - 100MB).
>Since reading with read.csv leads to "memory exhausted", I tried
>with scan(), skipping not needed columns by NULL-elements in
>"what".
>
>When these skipped elements are quoted strings with commata inside,
>R interprets each such quoted comma as element separator
>leading to wrong records in the rest of the line.
>
>A little test will show what I mean. I have the following "test.csv":
>
>"col.A","col.B","col.C","col.D"
>1,"quoted string","again, again again",123
>2,"nice quotes, isnt it","you got it",456
>
>First I read all elements:
>
> > tst <- scan("test.csv", what=list(a=0,b="",c="",d=0), sep=",", skip=1)
>Read 2 records
> > tst
>$a
>[1] 1 2
>
>$b
>[1] "quoted string" "nice quotes, isnt it"
>
>$c
>[1] "again, again again" "you got it"
>
>$d
>[1] 123 456
>
>Everything is fine. Then I try to skip the 2nd column by giving b=NULL:
>
> > tst <- scan("test.csv", what=list(a=0,b=NULL,c="",d=0), sep=",",
>skip=1)
>Read 2 records
>Warning message:
>number of items read is not a multiple of the number of columns
> > tst
>$a
>[1] 1 2
>
>$b
>NULL
>
>$c
>[1] "again, again again" " isnt it,you got it,456\n\n\n"
>
>$d
>[1] 123 NA
>
> >
>
>I got garbage.
>Isn't this a bug?
>Or did I something wrong?
>Is there a workaround?
>
>Thank you all,
>
>Paul Bayer,
>Feldafing, Germany
>
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