Inequalities into Standard Form

*To*: mathgroup at yoda.physics.unc.edu*Subject*: Inequalities into Standard Form*From*: Ronald D. Notestine <ronald at sccs.chukyo-u.ac.jp>*Date*: Wed, 22 Jun 94 22:35:58 +0900

Some time ago, I wrote asking how to put linear inequalities into standar form: with all variable terms on the lhs, and the constant term on the rhs. I wrote that I could make such a function myself, but hoped for something built-in or ready-made. Eventually, I asked WRI tech support, and am glad I did. Edmund Greaves, of WRI, immediately started in on the problem, and has sent me a far neater, and watertight, function than anything I would have made. Here is the function supplied by Ed Greaves of Wolfram Research: (I have to hand type everything, so any mistakes are mine.) convertIneq[ x_[lhs_,rhs_] ] := Module{temp,const,result}, temp = Expand[ lhs - rhs ]; (*all terms to rhs*) const = If[Head$ at {(J[temp] === Plus, Select[temp, NumberQ], 0]; result = x[temp-const, -const]; (* If a negative rhs is okay, done *) (* If need rhs non-negative... *) If[const>0, result = Map[ Minus, result]; result = result /. {Less -> Greater, LessEqual->GreaterEqual, Greater->Less, GreaterEqual->LessEqual}]; result ] I hope this is of help to any one with similar problems.