R help - Apr 2011 - extracting names from matrix according to a condition

Dear Community,

I have a matrix with assigned colnames and rolnames as follows:

            A            B
NR    0.15      0,05
AL     0,05      0,05
.           .            .
.           .            .
.           .            .

I want to extract the names of the rows for which A>0,1 and B<0,1. In
the above example this would be observation NR only. Hence the output
should write for instance:

names:
NR

Is this possible? Thank you very much for your help.

Best Regards

On 2011-04-25 10:58, ivan wrote:
> Dear Community,
>
> I have a matrix with assigned colnames and rolnames as follows:
>
>              A            B
> NR    0.15      0,05
> AL     0,05      0,05
> .           .            .
> .           .            .
> .           .            .
>
> I want to extract the names of the rows for which A>0,1 and B<0,1. In
> the above example this would be observation NR only. Hence the output
> should write for instance:
>
> names:
> NR
>
> Is this possible? Thank you very much for your help.
Call the matrix m. Then

  rownames(m[ m[, "A"] > 0.1 & m[, "B"] < 0.1, ,
drop=FALSE ])

should do what you want.

Peter Ehlers

thank you very much. worked great for me.

On Mon, Apr 25, 2011 at 8:22 PM, Peter Ehlers <ehlers at ucalgary.ca>
wrote:
> On 2011-04-25 10:58, ivan wrote:
>>
>> Dear Community,
>>
>> I have a matrix with assigned colnames and rolnames as follows:
>>
>> ? ? ? ? ? ? A ? ? ? ? ? ?B
>> NR ? ?0.15 ? ? ?0,05
>> AL ? ? 0,05 ? ? ?0,05
>> . ? ? ? ? ? . ? ? ? ? ? ?.
>> . ? ? ? ? ? . ? ? ? ? ? ?.
>> . ? ? ? ? ? . ? ? ? ? ? ?.
>>
>> I want to extract the names of the rows for which A>0,1 and
B<0,1. In
>> the above example this would be observation NR only. Hence the output
>> should write for instance:
>>
>> names:
>> NR
>>
>> Is this possible? Thank you very much for your help.
>
> Call the matrix m. Then
>
> ?rownames(m[ m[, "A"] > 0.1 & m[, "B"] < 0.1,
, drop=FALSE ])
>
> should do what you want.
>
> Peter Ehlers
>