[R] Parsing Files in R (USGS StreamFlow data)

Gabor Grothendieck ggrothendieck at gmail.com
Mon Oct 5 11:48:37 CEST 2009


Repeat the DD calculation but with this pattern instead:

 pat <- "^# +USGS +([0-9]+) +(.*)"

and then merge DD with DF:

DDdf <- data.frame(gauge = as.numeric(DD[,1]), gauage_name = DD[,2])
both <- merge(DF, DDdf, by = "gauge", all.x = TRUE)


On Sun, Oct 4, 2009 at 10:14 PM, Gabor Grothendieck
<ggrothendieck at gmail.com> wrote:
> Its not completely clear what you want to preserve and what you want
> to eliminate but try this:
>
>> L <- readLines("http://waterdata.usgs.gov/nwis/uv?format=rdb&period=7&site_no=021973269,06018500")
>
>> L.USGS <- grep("^USGS", L, value = TRUE)
>> DF <- read.table(textConnection(L.USGS), fill = TRUE)
>> head(DF)
>    V1       V2         V3    V4   V5   V6   V7
> 1 USGS 21973269 2009-09-27 00:00 6.96 4990 0.00
> 2 USGS 21973269 2009-09-27 00:15 6.96 4990 0.00
> 3 USGS 21973269 2009-09-27 00:30 6.97 5000 0.01
> 4 USGS 21973269 2009-09-27 00:45 6.97 5000 0.00
> 5 USGS 21973269 2009-09-27 01:00 6.98 5010 0.00
> 6 USGS 21973269 2009-09-27 01:15 6.98 5010 0.00
>
>> pat <- "^# +([0-9]+) +([0-9]+) +(.*)"
>> L.DD <- grep(pat, L, value = TRUE)
>> library(gsubfn)
>> DD <- strapply(L.DD, pat, c, simplify = rbind)
>> head(DD)
>     [,1] [,2]    [,3]
> [1,] "01" "00065" "Gage height, feet"
> [2,] "02" "00060" "Discharge, cubic feet per second"
> [3,] "03" "00045" "Precipitation, total, inches"
> [4,] "02" "00065" "Gage height, feet"
> [5,] "05" "00060" "Discharge, cubic feet per second"
>
>
> On Sun, Oct 4, 2009 at 9:49 PM, stephen sefick <ssefick at gmail.com> wrote:
>> http://waterdata.usgs.gov/nwis/uv?format=rdb&period=7&site_no=021973269
>>
>> I would like to be able to parse this file up:
>>
>> I can do this
>> x <- read.table("http://waterdata.usgs.gov/nwis/uv?format=rdb&period=7&site_no=021973269",
>> skip=26)
>>
>> but If I add another gauge to this
>>
>> x <- read.table("http://waterdata.usgs.gov/nwis/uv?format=rdb&period=7&site_no=021973269,06018500",
>> skip=26)
>> It does not work because there are two files appended to each other.
>>
>> It would be easy enough to write the code so that each individual
>> gauge would be read in as a different file, but is there a way to get
>> this information in using the commented part of the file to give the
>> headers?  This is probably a job for some other programing language
>> like perl, but I don't know perl.
>>
>> any help would be very helpful.
>> regards,
>>
>> --
>> Stephen Sefick
>>
>> Let's not spend our time and resources thinking about things that are
>> so little or so large that all they really do for us is puff us up and
>> make us feel like gods.  We are mammals, and have not exhausted the
>> annoying little problems of being mammals.
>>
>>                                                                -K. Mullis
>>
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>>
>



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