[R] Subarrays
Gunnar Hellmund
ghellmund at gmail.com
Fri Apr 29 17:33:36 CEST 2005
Define an array
> v<-1:256
> dim(v)<-rep(4,4)
Subarrays can be obtained as follows:
> v[3,2,,2]
[1] 71 87 103 119
> v[3,,,2]
[,1] [,2] [,3] [,4]
[1,] 67 83 99 115
[2,] 71 87 103 119
[3,] 75 91 107 123
[4,] 79 95 111 127
In the general case this procedure is very tedious.
Given an array
A, dim(A)=(dim_1,dim_2,...,dim_d)
and two vectors
v1=(n_i1,...n_ik), v2=(int_1,...,int_k) ('marginals' and relevant
'interval numbers')
is there a smart way to obtain
A[,...,int_1,....,int_2,....,....,int_k,....]
?
Best wishes
Gunnar Hellmund
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