I have data representing half of a symmetric matrix, in this form:
i j X
1 2 12
1 3 13
1 4 14
2 3 23
2 4 24
3 4 34
Is there an easy way of putting this into a matrix?
Currently I use an approach like this (variables are v1, v2 and v3,
matrix is A), but it feels clumsy:
-------------------------------------------------------------------
program define readdis /*reads cols into squared matrix*/
args dimension
local trsize = `dimension'*(`dimension'-1)/2
forvalues i = 1/`trsize' {
local i1 = v1[`i']
local j1 = v2[`i']
matrix A[`i1',`j1'] = v3[`i']
matrix A[`j1',`i1'] = v3[`i']
}
end
-------------------------------------------------------------------
Is there a cleaner way?
Brendan
--
Brendan Halpin, Department of Sociology, University of Limerick, Ireland
Tel: w +353-61-213147 f +353-61-202569 h +353-61-338562; Room F2-025 x 3147
mailto:[email protected] http://www.ul.ie/sociology/brendan.halpin.html
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