[R] Reshape - strange outputs

[stephen sefick]

can you provide a reproducible example?

On Wed, Apr 8, 2009 at 11:59 AM, Steve Murray <smurray444 at hotmail.com> wrote:
>
> Dear R Users,
>
> I am using the reshape package to reformat gridded data into column format using the code shown below. However, when I display the resulting object, a single column is fomed (instead of three) and all the latitude values (which should be in either column one or two) are collected at the bottom. Also, the NA values aren't removed, despite this being requested in the code.
>
> Code:
>
>
> # NetCDF file has been read in and is being processed...
>
> arunoff_1986_temp <- get.var.ncdf(netcdf_1036_temp, "arunoff")
>
>
> # Assign row and column names
>
> columnnames <- sprintf("%.2f", seq(from = -89.75, to = 89.75, length = 360))
> rnames <- sprintf("%.2f", seq(from = -179.75, to = 179.75, length = 720))
>
> colnames(arunoff_1986_temp) <- columnnames
> rownames(arunoff_1986_temp) <- rnames
>
>
> # Melt into columnar format
>
> arunoff_1986$Longitude <- rownames(arunoff_1986)
>    # Note: If I do: arunoff_1986$Latitude <- rownames(arunoff_1986)  (i.e. change it to 'Latitude', I get the following: Warning message: In arunoff_1986$Latitude <- rownames(arunoff_1986) : Coercing LHS to a list ), thus proceed using 'Longitude' where no warning is apparent.
>
>
> arunoff_long_1986 <- melt(arunoff_1986, id.var="Longitude", na.rm=TRUE)
>
>
>> dim(arunoff_long_1986)
> [1] 259560      2
>
>>head(arunoff_long_1986, n=10)  # This displays what looks like one single column, but is in fact two: column entitled "L1" is empty until the end of the file, as shown by the 'tail' command below.
>   value L1
> 1
> 2
> 3
> 4
> 5
> 6
> 7
> 8
> 9
> 10
>
>> tail(arunoff_long_1986, n=10)
>             value       L1
> Latitude.351 85.25 Latitude
> Latitude.352 85.75 Latitude
> Latitude.353 86.25 Latitude
> Latitude.354 86.75 Latitude
> Latitude.355 87.25 Latitude
> Latitude.356 87.75 Latitude
> Latitude.357 88.25 Latitude
> Latitude.358 88.75 Latitude
> Latitude.359 89.25 Latitude
> Latitude.360 89.75 Latitude
>
>
>
> I'd be very grateful indeed if anyone is able to offer assistance by way of pointing out what I've done wrong. I've spent a long time working on this and trying various options, but am srill none the wiser! I'm aiming for three columns: Latitude, Longitude, 'value'.
>
> Many thanks for any help offered,
>
> Steve
>
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> and provide commented, minimal, self-contained, reproducible code.
>



-- 
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