R help - Jul 2011 - error on my loop function

> t
Hi

I have to matrices t and y below. I want correlation of columns (a,d) (b,e)
and (c,f). The correlation should be for the first 3 rows of  matrix t
against matrix y; and then the last 3 i.e a loop function.

I have a code I created below but its giving me an error, surprisingly the
the individual parts of the code give me the correct answers.

##########My code is
> runs=2 
> Corrs=matrix(0, nrow=2,3)
> 
> for (i in 1:2)
+ {
+  index_start = 3*(i-1)+1  #replace 100 with days in a quater
+  index_end = 3*i  #replace 100 with days in a quater
+  use_index = index_start:index_end
+  Corrs[i] =diag(cor(t[use_index,],y[use_index,]))
+ }
Warning messages:
1: In Corrs[i] = diag(cor(t[use_index, ], y[use_index, ])) :
  number of items to replace is not a multiple of replacement length
2: In Corrs[i] = diag(cor(t[use_index, ], y[use_index, ])) :
  number of items to replace is not a multiple of replacement
length
> Corrs
     [,1] [,2] [,3]
[1,]    1    0    0
[2,]    1    0    0

####Expected solution

     [,1] [,2]       [,3]
[1,]    1   -1 -0.9226129
[2,]    1   -1 -0.8934051

###individual parts of the loop are
> diag(cor(t[1:3,],y[1:3,]))
[1]  1.0000000 -1.0000000 -0.9226129
> diag(cor(t[4:6,],y[4:6,]))
[1]  1.0000000 -1.0000000 -0.8934051

####my matrices  
>t
    a  b  c
[1,] 1 -1  4
[2,] 2 -2  6
[3,] 3 -3  9
[4,] 4 -4 12
[5,] 5 -5  6
[6,] 6 -6  5
> y
      d  e f
[1,]  6 -5 7
[2,]  7 -4 4
[3,]  8 -3 3
[4,]  9 -2 3
[5,] 10 -1 9
[6,] 11  0 7

Thank you in advance

Edward
UCT

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Hi,

In your loop, change Corrs[i] to Corrs[i,]

Weidong Gu


On Sat, Jul 16, 2011 at 12:02 PM, EdBo <n.bowora at gmail.com>
wrote:
>> t
> Hi
>
> I have to matrices t and y below. I want correlation of columns (a,d) (b,e)
> and (c,f). The correlation should be for the first 3 rows of ?matrix t
> against matrix y; and then the last 3 i.e a loop function.
>
> I have a code I created below but its giving me an error, surprisingly the
> the individual parts of the code give me the correct answers.
>
> ##########My code is
>
>> runs=2
>> Corrs=matrix(0, nrow=2,3)
>>
>> for (i in 1:2)
> + {
> + ?index_start = 3*(i-1)+1 ?#replace 100 with days in a quater
> + ?index_end = 3*i ?#replace 100 with days in a quater
> + ?use_index = index_start:index_end
> + ?Corrs[i] =diag(cor(t[use_index,],y[use_index,]))
> + }
> Warning messages:
> 1: In Corrs[i] = diag(cor(t[use_index, ], y[use_index, ])) :
> ?number of items to replace is not a multiple of replacement length
> 2: In Corrs[i] = diag(cor(t[use_index, ], y[use_index, ])) :
> ?number of items to replace is not a multiple of replacement length
>> Corrs
> ? ? [,1] [,2] [,3]
> [1,] ? ?1 ? ?0 ? ?0
> [2,] ? ?1 ? ?0 ? ?0
>
> ####Expected solution
>
> ? ? [,1] [,2] ? ? ? [,3]
> [1,] ? ?1 ? -1 -0.9226129
> [2,] ? ?1 ? -1 -0.8934051
>
> ###individual parts of the loop are
>
>> diag(cor(t[1:3,],y[1:3,]))
> [1] ?1.0000000 -1.0000000 -0.9226129
>
>> diag(cor(t[4:6,],y[4:6,]))
> [1] ?1.0000000 -1.0000000 -0.8934051
>
> ####my matrices
>>t
> ? ?a ?b ?c
> [1,] 1 -1 ?4
> [2,] 2 -2 ?6
> [3,] 3 -3 ?9
> [4,] 4 -4 12
> [5,] 5 -5 ?6
> [6,] 6 -6 ?5
>> y
> ? ? ?d ?e f
> [1,] ?6 -5 7
> [2,] ?7 -4 4
> [3,] ?8 -3 3
> [4,] ?9 -2 3
> [5,] 10 -1 9
> [6,] 11 ?0 7
>
> Thank you in advance
>
> Edward
> UCT
>
> --
> View this message in context:
http://r.789695.n4.nabble.com/error-on-my-loop-function-tp3672038p3672038.html
> Sent from the R help mailing list archive at Nabble.com.
>
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