Other constraints might be obtained from formulas for minimizing the difference between a product of variables and a linear combination of same.
min PROD x[j] - SUM c[k]*x[k] j in 1..n k in 1..n set the derivative with respect to x[L] to 0: PROD x[j] - c[L] = 0 for L in 1..n j in 1..n - {L} PROD x[j] = c[L] for L in 1..n j in 1..n - {L} multiplying n equations: PROD x[j]**(n-1) = PROD c[j] j in 1..n j in 1..n PROD x[j] = PROD c[j]**(1/(n-1) j in 1..n k in 1..n dividing: x[L] = c[L]**-1 * PROD c[j]**(1/(n-1)) j in 1..n Note that I have assumed c> 0 and x> 0 . -- Michael henne...@web.cs.ndsu.nodak.edu "Sorry but your password must contain an uppercase letter, a number, a haiku, a gang sign, a heiroglyph, and the blood of a virgin." -- someeecards _______________________________________________ Help-glpk mailing list Help-glpk@gnu.org https://lists.gnu.org/mailman/listinfo/help-glpk