_mds_euclidean.ado

是一个经济学管理应用软件 很难找的 但是经济学学生又必须用到

*! version 1.0.0  12feb2005
program _mds_euclidean
	args F colon Yexp
	
	assert inlist(`"`colon'"', ":", "=")

	tempname d Y 	
	
	matrix `Y' = `Yexp'
	local n = rowsof(`Y')
	
	matrix `F' = J(`n',`n',0)
	matrix rownames `F' = `:rownames `Y''
	matrix colnames `F' = `:rownames `Y''

	forvalues i = 1/`n' {
		forvalues j = 1 / `=`i'-1' {
			matrix `d' = `Y'[`i',1...]-`Y'[`j',1...]
			matrix `d' = `d'*`d''
			matrix `F'[`i',`j'] = sqrt(`d'[1,1])
			matrix `F'[`j',`i'] = `F'[`i',`j']
		}
	}
end	
exit

_mdseuclidean F {:|=} Y 

computes a square matrix F with the euclidean distances between the rows of Y
the number of columns of Y is arbitrary

note that the diagonal of F is 0