R distance matrix build

Question

New to R. I have a matrix of coordinates of several components in R, looks like:

    x   y   z
C1  0.3 0.2 -1.2
C2  -1.5    0.7 0
C3  0.2 -0.75   0.22
...

My question is how to build a distance matrix of pairs of each components in R like:

    C1  C2  C3  ...
C1  0   0.2 0.7 ...
C2  0.2 0   1.2 ...
C3  0.7 1.2 0   ...
...

score 5 · Accepted Answer · answered Dec 12 '12 at 15:38

5

You would do

as.matrix(dist(Matrix))

Then:

rownames(DistMatrix) <- colnames(DistMatrix) <- rownames(Matrix)

answered Dec 12 '12 at 15:38

Señor O

very useful, thanks. The distance calculated have 8 digits after the decimal point. Is there a way to shrink it? – lolibility Dec 12 '12 at 15:41
Yeah, I think since it's in matrix form you can just do `round(DistMatrix, digits=1)` to make it looks like your table above. – Señor O Dec 12 '12 at 15:48
More to the point: don't confuse *displayed* digits with *stored accuracy* . – Carl Witthoft Dec 12 '12 at 16:19

1 Answers1