[R] Convert back to lower triangular matrix

[Peter Langfelder]

On Tue, Nov 15, 2011 at 2:38 PM, Juliet Ndukum <jpntsang at yahoo.com> wrote:
> Given a vector;> ab = seq(0.5,1, by=0.1)> ab[1] 0.5 0.6 0.7 0.8 0.9 1.0
> The euclidean distance between the vector elements is given by the lower triangular matrix > dd1 = dist(ab,"euclidean")> dd1    1   2   3   4   52 0.1                3 0.2 0.1            4 0.3 0.2 0.1        5 0.4 0.3 0.2 0.1    6 0.5 0.4 0.3 0.2 0.1
> Convert the lower triangular matrix to a full matrix> ddm = as.matrix(dd1)> ddm    1   2   3   4   5   61 0.0 0.1 0.2 0.3 0.4 0.52 0.1 0.0 0.1 0.2 0.3 0.43 0.2 0.1 0.0 0.1 0.2 0.34 0.3 0.2 0.1 0.0 0.1 0.25 0.4 0.3 0.2 0.1 0.0 0.16 0.5 0.4 0.3 0.2 0.1 0.0
> I would be grateful if someone could provide me with a code to convert ddm to the lower triangular matrix as before i.e. dd1
>  above.

as.dist(ddm)

Peter