[R] Concatenate two strings in one in a string matrix

[David Winsemius]

On Aug 19, 2011, at 10:21 AM, David Winsemius wrote:

>
> On Aug 19, 2011, at 9:45 AM, Eduardo Mendes wrote:
>
>> Hello
>>
>> Many thanks.
>>
>> * is not a typo.   The output is a description of a nonlinear  
>> system so terms such as y(k-1)*y(k-2) are allowed.   I wonder  
>> whether "" could be ignored so that the outputs such as y_{01} 
>> (k-003)* would not show up.
>>
> Paste with "*"  then remove trailing "*"'s:
>
> ifelse( grepl("*$", result), sub("*","", result), result)

Rather (but still untested)

ifelse( grepl("\\*$", result), sub("\\*","", result), result)

-- 
david.
>
>> Cheers
>>
>> Ed
>>
>>
>> On Thu, Aug 18, 2011 at 3:40 PM, David Winsemius <dwinsemius at comcast.net 
>> > wrote:
>>
>> On Aug 18, 2011, at 2:35 PM, Eduardo Mendes wrote:
>>
>> Dear R-Users
>>
>> I have the following matrix
>>
>> out$desc      [,1]            [,2]
>> [1,] ""              ""
>> [2,] "y_{01}(k-001)" ""
>> [3,] "y_{01}(k-002)" ""
>> [4,] "y_{01}(k-003)" ""
>> [5,] "u_{01}(k-001)" ""
>> [6,] "u_{01}(k-002)" ""
>> [7,] "u_{01}(k-003)" ""
>> [8,] "y_{01}(k-001)" "y_{01}(k-001)"
>> [9,] "y_{01}(k-001)" "y_{01}(k-002)"
>> [10,] "y_{01}(k-001)" "y_{01}(k-003)"
>> [11,] "y_{01}(k-001)" "u_{01}(k-001)"
>>
>>
>> and need to concatenate each line to a single string.  Something like
>>
>> [2,] "y_{01}(k-001)" ""  -> [2,] "y_{01}(k-001)"
>>
>> [11,] "y_{01}(k-001)" "u_{01}(k-001)" -> [11,] "y_{01}(k-001)*u_{01} 
>> (k-001)"
>>
>> Is there a way to do it without going through every column?
>>
>> apply(out$desc, 1, paste, collapse="")
>>
>> It is ambiguous what you want for a delimiter. In one case you used  
>> "", and another you used "*". I used "".
>>
>>
>> -- 
>>
>> David Winsemius, MD
>> West Hartford, CT
>>
>>
>
> David Winsemius, MD
> West Hartford, CT
>
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David Winsemius, MD
West Hartford, CT