[R] extracting information from txt file

[jim holtman]

Using na.string works better:

> x <- read.csv("http://www.epa.gov/emap/html/data/surfwatr/data/mastreams/9396/wchem/chmval.txt", skip=84, as.is = TRUE, na.string = '.')
> str(x)
'data.frame':   711 obs. of  75 variables:
 $ ALDI    : int  NA NA NA NA NA NA NA NA NA NA ...
 $ ALDS    : chr  NA "S" "S" "S" ...
 $ ALDSF   : chr  " " " " " " " " ...
 $ ALKCALC : num  106 210.7 73.5 432.6 38.7 ...
 $ ALOR    : chr  NA "S" "S" "S" ...
 $ ALORF   : chr  " " " " " " " " ...
 $ ALTD    : int  54 36 47 12 19 10 12 5 8 6 ...
 $ ALTDF   : chr  " " " " " " " " ...
 $ ANC     : num  115 207.2 82.2 435.2 37.4 ...
 $ ANCF    : chr  " " " " " " " " ...
 $ ANDEF   : num  82.5 52.3 31.8 21.9 12.2 ...
 $ ANSUM   : num  771 728 328 892 251 ...
 $ CA      : num  303 529 182 392 124 ...


On Wed, Oct 31, 2012 at 12:46 PM, chuck.01 <CharlieTheBrown77 at gmail.com> wrote:
> Hello,
>
> Here is a link to some data:
> http://www.epa.gov/emap/html/data/surfwatr/data/mastreams/9396/wchem/chmval.txt
>
> I am trying to read this in, and want to use:
> chmval <-
> read.table("http://www.epa.gov/emap/html/data/surfwatr/data/mastreams/9396/wchem/chmval.txt",
> sep=",", skip= 84, header=T)
>
> the # 84, for 84 lines skipped needs to be derived from the 5th line of the
> txt file
> # Header Records:  85
>
> so, I need that # (-1) for input into the read.table statement above
>
> I've tried grep but that didn't work:
>  (for this I downloaded the txt file and manually removed that hash mark!)
>
> grep("Header Records:", read.table("chmval.txt", header=T))
> Error in scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings,
> :
>   line 1 did not have 5 elements
>
> Any ideas?
> Can I just extract the 5th line?
>
>
>
>
> --
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>
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-- 
Jim Holtman
Data Munger Guru

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Tell me what you want to do, not how you want to do it.