[R] Simple... but...

Wacek Kusnierczyk Waclaw.Marcin.Kusnierczyk at idi.ntnu.no
Wed Jul 23 16:06:27 CEST 2008


it's clear, he wants to combine x and y s that the result is (x[1],
y[1], x[2], y[2], ...), unless i am confused as well ;)

now, both rbind(x,y)[1:length(x)] and as.vector(mapply(c,x,y)) do the
job, but the former is *much* faster:

t1 = function(n) as.vector(mapply(c, 1:n, 1:n))
t2 = function(n) rbind(1:n,1:n)[1:(2*n)]

system.time(t1(10^6)) # ~7sec
system.time(t2(10^6)) # < 1sec

system.time(replicate(10^5, t1(10))) # ~20sec
system.time(replicate(10^5, t2(10))) # ~1sec

vQ







Doran, Harold wrote:
> Shubba
>
> I'm confused. Your first post said the result should be c(1,2,3,4,5,6)
> when x and y are combined. The code I sent does that. But here you say
> your result should be c(4,1,2,5,2,3).
>
> What do you want your result to actually be? 
>
>   
>> -----Original Message-----
>> From: Shubha Vishwanath Karanth [mailto:shubhak at ambaresearch.com] 
>> Sent: Wednesday, July 23, 2008 9:17 AM
>> To: Doran, Harold; r-help at stat.math.ethz.ch
>> Subject: RE: [R] Simple... but...
>>
>> OK,
>>
>> Let x=c(4,2,2)
>> 	y=c(1,5,3)
>>
>> My result should be c(4,1,2,5,2,3)
>>
>> Thanks, Shubha
>>  
>> -----Original Message-----
>> From: Doran, Harold [mailto:HDoran at air.org]
>> Sent: Wednesday, July 23, 2008 6:47 PM
>> To: Shubha Vishwanath Karanth; r-help at stat.math.ethz.ch
>> Subject: RE: [R] Simple... but...
>>
>> x <-  c(1,3,5)
>> y <-  c(2,4,6)
>>
>> sort(c(x,y))
>>
>>     
>>> -----Original Message-----
>>> From: r-help-bounces at r-project.org
>>> [mailto:r-help-bounces at r-project.org] On Behalf Of Shubha 
>>>       
>> Vishwanath 
>>     
>>> Karanth
>>> Sent: Wednesday, July 23, 2008 8:55 AM
>>> To: r-help at stat.math.ethz.ch
>>> Subject: [R] Simple... but...
>>>
>>> Hi R,
>>>
>>>  
>>>
>>> If
>>>
>>> x=c(1,3,5)
>>>
>>> y=c(2,4,6)
>>>
>>>  
>>>
>>> I need a vector which is c(1,2,3,4,5,6) from x and y.
>>>
>>>  
>>>
>>> How do I do it? I mean the best way....
>>>
>>>  
>>>
>>> Thanks, Shubha
>>>
>>>  
>>>
>>> This e-mail may contain confidential and/or privileged 
>>> i...{{dropped:13}}
>>>
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>>>
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>
> ______________________________________________
> R-help at r-project.org mailing list
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
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>   


-- 
-------------------------------------------------------------------------------
Wacek Kusnierczyk, MD PhD

Email: waku at idi.ntnu.no
Phone: +47 73591875, +47 72574609

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