[R] fill a dataframe with zeros where the rows are a smaller subset of a larger dataframe (species by site)

[Stephen Sefick]

Thank you all very much, that did the trick.

Stephen

On Wed 25 Apr 2012 09:59:38 AM CDT, Sarah Goslee wrote:
> The clarification helps; the original description was rather terse.
>
> What about:
>
>> row<- c("a","b","c","d","e","f","g") #rows from larger data frame
>>
>> x<- data.frame(sp1=rnorm(4), sp2=rnorm(4), sp3=rnorm(4), sp4=rnorm(4))
>>
>> rownames(x)<- row.1
>>
>> merge(x, matrix(row, ncol=1), by.x=0, by.y=1, all=TRUE)
>    Row.names        sp1        sp2        sp3        sp4
> 1         a  0.4964272  1.4989159  0.4302415  0.9648854
> 2         b  1.4137142  0.9430609  0.0728391 -0.6275084
> 3         c -0.8103023 -1.3375148 -0.3799518  0.4523287
> 4         d         NA         NA         NA         NA
> 5         e         NA         NA         NA         NA
> 6         f         NA         NA         NA         NA
> 7         g -0.1914184  0.5156566  0.5626614  0.8068154
>
> Sarah
>
> On Wed, Apr 25, 2012 at 10:42 AM, Stephen Sefick<sas0025 at auburn.edu>  wrote:
>> I am subsetting a larger data frame that contains macroinverterate taxa.  I
>> am subsetting them at different levels of taxonomic resolution.  Some of the
>> sites do not have say Tipulidae present, so the rows are removed completely
>> for this site.  I would like to fill in the sites that were removed during
>> the subsetting and fill these with 0.  I have the non-subsetted dataframe
>> which contains all of the sites.  I would like to use the sites from this
>> complete data set to "expand" the dataframe that is a subset of the sites in
>> the original.  Is that more clear.
>>
>> Stephen
>>

--
Stephen Sefick
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Auburn University
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