R help - Oct 2014 - reading in hexadecimal data - not working with data ending in E

I am trying to read in data from an instrument that is recorded in 
hexadecimal format. Using either: 

    y.hex <- read.table(file="hex.data", as.is=TRUE) 

or 

    y.hex <- read.table(file="hex.data", text=TRUE) 

gets all the data in just fine except points like `055E` or `020E`. In 
these cases, the E is stripped so I get just 055 or 020. 

The question is how should this data be imported to avoid the E-ending 
problem? 

(By the way, my follow-up is to convert this data using, `y <- 
strtoi(y.hex, 16L)`) 

Thanks for any suggestions, 

Mark Hogue 
	[[alternative HTML version deleted]]

On 08/10/2014 7:02 AM, mark.hogue at srs.gov wrote:
> I am trying to read in data from an instrument that is recorded in
> hexadecimal format. Using either:
>
>      y.hex <- read.table(file="hex.data", as.is=TRUE)
>
> or
>
>      y.hex <- read.table(file="hex.data", text=TRUE)
>
> gets all the data in just fine except points like `055E` or `020E`. In
> these cases, the E is stripped so I get just 055 or 020.
You need to read the ?read.table help.  as.is and text don't do anything 
like what you want.

The argument you need to use is colClasses.  I think you want to set it 
to "character".

Duncan Murdoch
>
> The question is how should this data be imported to avoid the E-ending
> problem?
>
> (By the way, my follow-up is to convert this data using, `y <-
> strtoi(y.hex, 16L)`)
>
> Thanks for any suggestions,
>
> Mark Hogue
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> 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.

I did not see a reproducible example, but you should use
colClasses="character" to
read in the data as character, then use something like as.hexmode() to
convert it to integers.  E.g.,

  > z <- read.table(text="ColA ColB\n1e 33\n2e  44\n10  5e\n",
header=TRUE, colClasses="character")
  > str(z)
  'data.frame':   3 obs. of  2 variables:
   $ ColA: chr  "1e" "2e" "10"
   $ ColB: chr  "33" "44" "5e"
  > z[] <- lapply(z, function(zi)as.integer(as.hexmode(zi)))
  > str(z)
  'data.frame':   3 obs. of  2 variables:
   $ ColA: int  30 46 16
   $ ColB: int  51 68 94

If you leave out the colClasses="character" then read.table will say
that all those
strings look like decimal numerals ("1e" being read as
"1e+0", giving 1*10^0).


Bill Dunlap
TIBCO Software
wdunlap tibco.com


On Wed, Oct 8, 2014 at 4:02 AM,  <mark.hogue at srs.gov>
wrote:
> I am trying to read in data from an instrument that is recorded in
> hexadecimal format. Using either:
>
>     y.hex <- read.table(file="hex.data", as.is=TRUE)
>
> or
>
>     y.hex <- read.table(file="hex.data", text=TRUE)
>
> gets all the data in just fine except points like `055E` or `020E`. In
> these cases, the E is stripped so I get just 055 or 020.
>
> The question is how should this data be imported to avoid the E-ending
> problem?
>
> (By the way, my follow-up is to convert this data using, `y <-
> strtoi(y.hex, 16L)`)
>
> Thanks for any suggestions,
>
> Mark Hogue
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> 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.

On Wed, Oct 8, 2014 at 6:02 AM, <mark.hogue at srs.gov> wrote:
> I am trying to read in data from an instrument that is recorded in
> hexadecimal format. Using either:
>
>     y.hex <- read.table(file="hex.data", as.is=TRUE)
>
> or
>
>     y.hex <- read.table(file="hex.data", text=TRUE)
>
> gets all the data in just fine except points like `055E` or `020E`. In
> these cases, the E is stripped so I get just 055 or 020.
>
> The question is how should this data be imported to avoid the E-ending
> problem?
>
> (By the way, my follow-up is to convert this data using, `y <-
> strtoi(y.hex, 16L)`)
>
> Thanks for any suggestions,
>
?Please don't post in HTML, it is against forum policy. And it often
results in poorly formatted messages, which many ignore.?

?Try:

y.hex <-
read.table(file="hex.data",as.is=TRUE,colClasses="character");?


>
> Mark Hogue
>

-- 
There is nothing more pleasant than traveling and meeting new people!
Genghis Khan

Maranatha! <><
John McKown

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