R help - Oct 2019 - read.table and NaN

Hi,

Is there a way to make read.table consider NaN as a string of characters rather
than the internal NaN? Changing the na.strings argument does not seems to have
any effect on how R interprets the NaN string (while is does not the the NA
string)

con <- textConnection(object = 'A,B\n1,NaN\nNA,2')
tmp <- read.table(con, header = TRUE, sep = ',', na.strings =
'', stringsAsFactors = FALSE)
close.connection(con)
tmp
class(tmp[,1])
class(tmp[,2])

Like this?

con <- textConnection(object =
'A,B\n1,NaN\nNA,2')
> tmp <- read.table(con, header = TRUE, sep = ',', na.strings =
'',
stringsAsFactors = FALSE,
+                   colClasses = c("numeric",
"character"))
> close.connection(con)
> tmp
   A   B
1  1 NaN
2 NA   2
> class(tmp[,1])
[1] "numeric"
> class(tmp[,2])
[1] "character"
> tmp[,2]
[1] "NaN" "2"


Bert Gunter

"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Wed, Oct 23, 2019 at 6:31 PM Sebastien Bihorel via R-help <
r-help at r-project.org> wrote:
> Hi,
>
> Is there a way to make read.table consider NaN as a string of characters
> rather than the internal NaN? Changing the na.strings argument does not
> seems to have any effect on how R interprets the NaN string (while is does
> not the the NA string)
>
> con <- textConnection(object = 'A,B\n1,NaN\nNA,2')
> tmp <- read.table(con, header = TRUE, sep = ',', na.strings =
'',
> stringsAsFactors = FALSE)
> close.connection(con)
> tmp
> class(tmp[,1])
> class(tmp[,2])
>
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
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Thanks Gunter

It seems that one has to know the structure of the data and adapt the read.table
call accordingly. I am working on a framework that is meant to process data
files with unknown structure, so I have to think a bit more about that...
________________________________
From: Bert Gunter <bgunter.4567 at gmail.com>
Sent: Thursday, October 24, 2019 00:08
To: Sebastien Bihorel <Sebastien.Bihorel at cognigencorp.com>
Cc: r-help at r-project.org <r-help at r-project.org>
Subject: Re: [R] read.table and NaN

Like this?

con <- textConnection(object =
'A,B\n1,NaN\nNA,2')
> tmp <- read.table(con, header = TRUE, sep = ',', na.strings =
'', stringsAsFactors = FALSE,
+                   colClasses = c("numeric",
"character"))
> close.connection(con)
> tmp
   A   B
1  1 NaN
2 NA   2
> class(tmp[,1])
[1] "numeric"
> class(tmp[,2])
[1] "character"
> tmp[,2]
[1] "NaN" "2"


Bert Gunter

"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Wed, Oct 23, 2019 at 6:31 PM Sebastien Bihorel via R-help <r-help at
r-project.org<mailto:r-help at r-project.org>> wrote:
Hi,

Is there a way to make read.table consider NaN as a string of characters rather
than the internal NaN? Changing the na.strings argument does not seems to have
any effect on how R interprets the NaN string (while is does not the the NA
string)

con <- textConnection(object = 'A,B\n1,NaN\nNA,2')
tmp <- read.table(con, header = TRUE, sep = ',', na.strings =
'', stringsAsFactors = FALSE)
close.connection(con)
tmp
class(tmp[,1])
class(tmp[,2])


______________________________________________
R-help at r-project.org<mailto:R-help at r-project.org> mailing list -- To
UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

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