[R-sig-teaching] length of vectors with tapply

[Steven Stoline]

got it

many thanks

Steven

On Tue, Sep 9, 2014 at 11:16 PM, Mark Daniel Ward <mdw at purdue.edu> wrote:

> Dear Steven,
>
> If you remove the parameter:
> na.rm=TRUE
> then your example seems to work fine for me.  Good luck!
>
> Best wishes,
> Mark
>
> Mark Daniel Ward, Ph.D.
> Associate Professor and Undergraduate Chair
> Department of Statistics
> Purdue University
> 150 North University Street
> West Lafayette, IN 47907-2067
> mdw at purdue.edu
> phone: (765) 496-9563
>
>
>
>
> On 9/9/14, 11:12 PM, Steven Stoline wrote:
>
>> Dear All:
>>
>> I was trying to get the lengths of vectors using "length" in tapply as
>> follows:
>>
>> ni<-tapply(data[,2], data[,2], length, na.rm=TRUE)
>>
>> but it did not work for me. I am not sure what I am doing wrong.
>>
>> I am not sure if I should use different function.
>>
>> Here is the data:
>> ============
>> data<-matrix(c(8,24,0,0,16,32,6,0,16,7,4,4,9,5,8,18,2,0,4,0,
>> 8,3,1,5,24,12,2,8,1,8,
>> 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,3,3),30,2)
>>
>>
>>
>> The answer should be:
>>
>> ni: 18  ,  10  ,  2
>>
>>
>> thank you very much
>> Steven
>>
>>
>


-- 
Steven M. Stoline
1123 Forest Avenue
Portland, ME 04112
sstoline at gmail.com

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