R help - Mar 2003 - for loop problem

Hi,
I'm just coming to grips with "for" looping etc. and have a bit of
a
problem:

I want to generate a sequence which goes
1 2 3 4 5 6 7 8 14 15 16 17 18 19 20 21 26 27 ...
i.e. 8 consecutive numbers then 5 missed then the next 8 numbers etc.
I was going to do this using the seq() function but couldn't figure out how 
so I thought I'd try a loop:

for (x in seq(1,650,13))
{ num.set.1 <- x:x+8
}
but now what I need to do is write code such that each time it goes through 
the loop it assigns the output to a different object e.g. num.set.1 on the 
first loop then num.set.2 on the next etc. so that they can be concatenated. 
Is there any way to do this??

I may be doing this an extremely complicated way but with my zero 
programming experience its the best I can think of. Can anyone help?

J

Your sequence is 1:a + k*(a+b) where a=8, b=5 and k=0,1,...,K. You can
make use of the fact that R loops of vectors if two vectors are not the
same;

  a <- 8
  b <- 5
  K <- 49
  x <- rep((0:K)*(a+b), each=a) + 1:a

Cheers

Henrik Bengtsson
> -----Original Message-----
> From: r-help-admin at stat.math.ethz.ch 
> [mailto:r-help-admin at stat.math.ethz.ch] On Behalf Of Jeremy Z Butler
> Sent: den 4 mars 2003 14:14
> To: r-help at stat.math.ethz.ch
> Subject: [R] for loop problem
> 
> 
> Hi,
> I'm just coming to grips with "for" looping etc. and have a
bit of a
> problem:
> 
> I want to generate a sequence which goes
> 1 2 3 4 5 6 7 8 14 15 16 17 18 19 20 21 26 27 ...
> i.e. 8 consecutive numbers then 5 missed then the next 8 
> numbers etc. I was going to do this using the seq() function 
> but couldn't figure out how 
> so I thought I'd try a loop:
> 
> for (x in seq(1,650,13))
> { num.set.1 <- x:x+8
> }
> but now what I need to do is write code such that each time 
> it goes through 
> the loop it assigns the output to a different object e.g. 
> num.set.1 on the 
> first loop then num.set.2 on the next etc. so that they can 
> be concatenated. 
> Is there any way to do this??
> 
> I may be doing this an extremely complicated way but with my zero 
> programming experience its the best I can think of. Can anyone help?
> 
> J
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list 
> http://www.stat.math.ethz.ch/mailman/listinfo/> r-help
> 
>

"Jeremy Z Butler" <jerrytheshrub at hotmail.com> writes:
> Hi,
> I'm just coming to grips with "for" looping etc. and have a
bit of a
> problem:
> 
> 
> I want to generate a sequence which goes
> 1 2 3 4 5 6 7 8 14 15 16 17 18 19 20 21 26 27 ...
> i.e. 8 consecutive numbers then 5 missed then the next 8 numbers etc.
> I was going to do this using the seq() function but couldn't figure
> out how so I thought I'd try a loop:
> 
> 
> for (x in seq(1,650,13))
> { num.set.1 <- x:x+8
> }
> but now what I need to do is write code such that each time it goes
> through the loop it assigns the output to a different object
> e.g. num.set.1 on the first loop then num.set.2 on the next etc. so
> that they can be concatenated. Is there any way to do this??
> 
> 
> I may be doing this an extremely complicated way but with my zero
> programming experience its the best I can think of. Can anyone help?
I suggest using a matrix.
> mseq = as.vector(matrix(1:650, nrow = 13)[1:8,])
> length(mseq)
[1] 400
> mseq[1:20]
 [1]  1  2  3  4  5  6  7  8 14 15 16 17 18 19 20 21 27 28 29 30

On Tue, 04 Mar 2003, Jeremy Z. Butler told this:
>  I want to generate a sequence which goes 1 2 3 4 5 6 7 8 14 15 16 17 18 19
>  20 21 26 27 ...  i.e. 8 consecutive numbers then 5 missed then the next 8
>  numbers etc.  I was going to do this using the seq() function but
couldn't
>  figure out how so I thought I'd try a loop:
>  
>  for (x in seq(1,650,13))
>  { num.set.1 <- x:x+8
                  ^^^^^   should be x:(x+8) 
>  }
and by all means, avoid for loop, think in vector.

Michael