Array: make vector positions from symmetric array index

make vector positions from (non-symmetric) array index respecting dim and fixdiag

symmIndex2vectorIndex(x, dim, fixdiag = NULL)

Arguments

x

a matrix[,1:2] with matrix subscripts

dim

the dimensions of the symmetric matrix

fixdiag

NULL assumes free diagonal, any value assumes fixed diagonal

Details

With fixdiag = NULL

Value

a vector of indices in seq_len(prod(dim(x)))

Author

Jens Oehlschlägel

See also

arrayIndex2vectorIndex

Examples

  symmIndex2vectorIndex(rbind(
   c(1,1)
  ,c(1,10)
  ,c(10,1)
  ,c(10,10)
  ), dim=c(10,10))
#> [1]  1 10 10 55
  symmIndex2vectorIndex(rbind(
   c(1,1)
  ,c(1,10)
  ,c(10,1)
  ,c(10,10)
  ), dim=c(10,10), fixdiag=1)
#> [1] NA  9  9 NA