R help - May 2009 - Select the rows in a dataframe that matches a criteria in another dataframe

Hi everyone! Thank you for the help you have been given to 
me, and here I'm with another problem with my dataframes:
  
I have two dataframes (with much more observations), like 
these:
Dataframe1
Firm         Year      cash
500400200    2007     100
500400200    2006     200
500400200    2005     400
500400300    2007     300
500400300    2006     240
500400300    2005     120
500400400    2007     340
500400400    2006     890
500400400    2005     250

Dataframe 2
Firm            Audited     consolidate
500400200     yes           no
500400300     yes          yes
500400400     no            no

I want to make another dataframe equal to the dataframe1, 
but just with the firms ?audited?, or with the firms 
?audited? and ?consolidate?. For example, with the audited 
and consolidated, the output would be just firm 500400300, 
like this:
Firm         Year      cash
500400300    2007     300
500400300    2006     240
500400300    2005     120

I?ve tried intersect () but it gives me just the number of 
the firm, and it is not what I want. What I want is a 
dataframe with all the information, but just the firms 
that match my criteria.

Could anyone help me with another function?

Thank you in advance,

Cec?lia Carmo (Portugal)

?subset
?"%in%"

(I have gotten tired of converting dataframes that are presented in a  
non-executable form, such as is supported by the dput function.   
So, ... you should read those help pages and take the obvious path to  
success.)

Something along the lines of:

subset(df1, Firm %in% df2[df2$Audited==yes, "Firm"] )  #untested

-- 
David Winsemius

On May 10, 2009, at 5:52 PM, Cecilia Carmo wrote:
> Hi everyone! Thank you for the help you have been given to me, and  
> here I'm with another problem with my dataframes:
> I have two dataframes (with much more observations), like these:
> Dataframe1
> Firm         Year      cash
> 500400200    2007     100
> 500400200    2006     200
> 500400200    2005     400
> 500400300    2007     300
> 500400300    2006     240
> 500400300    2005     120
> 500400400    2007     340
> 500400400    2006     890
> 500400400    2005     250
>
> Dataframe 2
> Firm            Audited     consolidate
> 500400200     yes           no
> 500400300     yes          yes
> 500400400     no            no
>
> I want to make another dataframe equal to the dataframe1, but just  
> with the firms ?audited?, or with the firms ?audited? and  
> ?consolidate?. For example, with the audited and consolidated, the  
> output would be just firm 500400300, like this:
> Firm         Year      cash
> 500400300    2007     300
> 500400300    2006     240
> 500400300    2005     120
>
> I?ve tried intersect () but it gives me just the number of the firm,  
> and it is not what I want. What I want is a dataframe with all the  
> information, but just the firms that match my criteria.
David Winsemius, MD
Heritage Laboratories
West Hartford, CT