[Rd] Subscripting Matrices

Terrence Ireland kyzyl at his.com
Wed Aug 6 17:07:42 CEST 2014


There seems to be a result type difference when subscripting a 6 x 1 
matrix as compared to a 3 x 2 matrix that is caused by the ncol = 1 
compared to ncol > 1.

 > ThinMatrix <- matrix(1:6,ncol=1)
 > ThinMatrix
      [,1]
[1,]    1
[2,]    2
[3,]    3
[4,]    4
[5,]    5
[6,]    6
 > FatMatrix <- matrix(1:6,ncol=2)
 > FatMatrix
      [,1] [,2]
[1,]    1    4
[2,]    2    5
[3,]    3    6
 > dim(ThinMatrix[TRUE,])
NULL                                      #Though this value should be 6 1
 > dim(FatMatrix[TRUE,])
[1] 3 2

Thanks for your help.

Terry Ireland



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