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Count values of a column if value in other column >x and create new data frame

Submitted by crnv on May 31, 2012

I have the following data structure (which was actually created by counting the occurences of "Result" with ddply):

Experiment Result Count
         A      1   123
         A      2   30
         A      3   5
         B      1   120
         B      2   20
         B      3   5
         B      4   1
         B      5   1
         C      1   130
         C      2   21
...

I want to create a similar data frame that groups (calculates sum) of all results that are greater than 2.

Expected outcome: 

Experiment Result Count
         A      1   123
         A      2    30
         A     >2     5
         B      1   120
         B      2    20
         B     >2     7
         C      1   130
         C      2    21
...

Probably plyr can do this but I am new to R and have no idea how to use a custom condition (i.e. result 1,2,>2) and not just the distinct values of a column.

Note: I do not mind the name of the new bin (i.e., may be != '<2').