[R] possible reason for merge not working

[David Winsemius]

On Aug 1, 2011, at 12:17 PM, world peace wrote:

> Hi Guys,
>
> working on a "merge" for 2 data frames.
>
> Using the command:
>
> x <- merge(annotatedData, UCSCgenes, by.x="names",
> by.y="Ensembl.Gene.ID", all.x=TRUE)
>
> names and Ensembl.Gene.ID are columns with similar elements from the x
> and y data frames.
>
> annotatedData has 8909 entries, so has x(as expected). x has columns
> for UCSCgenes, but there is no data in them, all n/a, as if no match
> exists.
> This is not true as I can manually see and find many similarities

The merge function does not work on "similarities". Matches need to be  
exact.

> between the names and UCSCgenes columns.
>
> I am wondering if there is any syntax error, or logical.

Probably logical.

-- 

David Winsemius, MD
West Hartford, CT