Re: squared norm in Mathematica

*To*: mathgroup at smc.vnet.net*Subject*: [mg85778] Re: [mg85764] squared norm in Mathematica*From*: Curtis Osterhoudt <cfo at lanl.gov>*Date*: Fri, 22 Feb 2008 04:58:48 -0500 (EST)*Organization*: LANL*References*: <200802212302.SAA18356@smc.vnet.net>*Reply-to*: cfo at lanl.gov

Hi, Syed, Though I can't necessarily read your FindMinimum command (it seems to contain some non-standard characters), I think I see what the problem is. That error message almost always crops up when you've tried to assign a value to something which isn't allowed to be assigned to. In other words, I suspect you have to replace the single equals sign ( = ) in "-4+x12+x22+x32+x42=0" with a double one ( == ). I hope that helps! C.O. On Thursday 21 February 2008 16:02:29 syed qasim Ali wrote: > Dear Sir, > My problem was actually > > ||SX||^2 > > i was trying it as multiobjective optimiztaion in Mathematica but i got > to know that it can be programmed as single objective .... > > ||SX||^2=(a11*x1 + a12*x2 + a13*x3)^2 + (a21*x1 + a22*x2 + > > a23*x3)^2 + (a31*x1 + a32*x2 + a33*x3)^2. > > > therefore my problem becomes > > x1 >= 0.52, <= 1.47; > x2 >= 0.52, <= 1.47; > x3 >= 0.52, <= 1.47; > x4 >= 0.52, <= 1.47; > > > > minimize : ( ((-0.22*x1)+(0.13*x2)+(-0.09*x3)+(0.07*x4))^2 + > ((-0.13*x1)+(0.09*x2)+(-0.07*x3)+(0.058*x4))^2 +((-0.09*x1)+(0.07*x2)+ > (-0.058*x3)+(0.049*x4))^2); > > > subject to: > -4+x1^2+x2^2+x3^2+x4^2=0; > > > IN Mathematica it becomes > > FindMinimum[{(-0.22 g1+0.13 g2-0.09 g3+0.07 g4)2+(-0.13 x1+0.09 x2-0.07 > x3+0.058 x4)2+(-0.09 x1+0.07 x2-0.058 x3+0.049 > x4)2,-4+x12+x22+x32+x42=0&&0.52=A3x1=A31.47,0.52=A3x2=A31.47,0.52=A3x3=A31.47,0.5 >2=A3x4=A31.47},{x1,x2,x3,x4}] > > > i have this result when i tried this problem in Mathematica ....i guess > Mathematica can handle this problem > > Set::write : Tag Plus in > -4+x12+x22+x32+x42 is Protected > FindMinimum::eqineq : Constraints in > {0,0.52=A3x1,0.52=A3x2,0.52=A3x3,0.52=A3x4,x1=A31.47,x2=A31.47,x3=A31.47,x4=A31.47} > are not all equality or inequality constraints. With the exception of > integer domain constraints for linear programming, domain constraints or > constraints with Unequal (!=) are not supported. > > i donot understand where the fault lies ...when i have only one objective > function > > > thanx - ========================== ========================== ======== Curtis Osterhoudt cfo at remove_this.lanl.and_this.gov PGP Key ID: 0x4DCA2A10 Please avoid sending me Word or PowerPoint attachments See http://www.gnu.org/philosophy/no-word-attachments.html ========================== ========================== ========

**References**:**squared norm in Mathematica***From:*syed qasim Ali <edu_forme@yahoo.com>