[R] matrix loop

David Winsemius dwinsemius at comcast.net
Sat Feb 9 21:00:52 CET 2008


John Kane <jrkrideau at yahoo.ca> wrote in
news:375101.56779.qm at web32803.mail.mud.yahoo.com: 

> You are trying to create a matrix in the loop 
> 
> Try creating the matrix before the loop
>  m <- 1:5
>  n<-1:10
>  y <- matrix(rep(NA, 50), nrow=m)

# I think that this might actually work:

y <- matrix(rep(NA, 50), nrow=max(m))

>  for(i in 1:length(m))
>  { for(j in 1:length(n))
>   {
>   y[i,j]=sum(i,j)
>   }
>   }

#produced:
Error in y[i, j] = sum(i, j) : subscript out of bounds

-- 
David Winsemius

> 
> However as Jim Holtman points out you can do this
> particular matrix by
> 
>   outer(1:5, 1:10, "+")
> 
> 
> --- mohamed nur anisah <nuranisah_mohamed at yahoo.com>
> wrote:
> 
>> Dear list,
>>    
>>   I'm trying to make a loop of a (5x10) matrix and
>> below are my codes. Could anybody help me figure out
>> why my loop is not working. Thanks in advance!!
>>    
>>    
>>   m<-1:5
>> n<-1:10
>> for(i in 1:length(m))
>> { for(j in 1:length(n))
>>  { 
>>   y[i,j]=sum(i,j)
>>   y<-as.matrix(y[i,j]) 
>>  }
>>   }
>>   cheers,



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