R help - Apr 2008 - distance matrix as text file - how to import?

Dear all,

I have -hopefully- a tiny problem.

I was sent a text file containing a distance matrix ? la:

1
2 3
4 5 6

Now I wanted to import these data into a dist object to, let's say,  
do 'plot(hclust(v))'.

My first na?ve approach was to scan the text file in order to get a  
vector v. Then I did:

class(v) <- "dist"
attr(v, "Size") <- 4

But, of course, I got this:

1
2 4
3 5 6

I wonder if there's an elegant way to do it. The only way I know of  
is very very stony one.

I'd be very appreciated for any hint.

Cheers,

--Hans

On Tue, Apr 8, 2008 at 1:50 PM, Hans-J?rg Bibiko <bibiko at eva.mpg.de>
wrote:
> Dear all,
>
>  I have -hopefully- a tiny problem.
>
>  I was sent a text file containing a distance matrix ? la:
>
>  1
>  2 3
>  4 5 6
>

Try this! I put your test data in "text.txt" and voila:


mat <- matrix(0, 3,3)

mat[row(mat) >= col(mat)] <- scan("test.txt")


I found this Idea after "RSiteSearch("scan triangular") led to
this
item as the very first link:

http://finzi.psych.upenn.edu/R/Rhelp02a/archive/22369.html


PJ


-- 
Paul E. Johnson
Professor, Political Science
1541 Lilac Lane, Room 504
University of Kansas