Re: Re: Radicals simplify

*To*: mathgroup at smc.vnet.net*Subject*: [mg106442] Re: [mg106439] Re: Radicals simplify*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Wed, 13 Jan 2010 05:55:20 -0500 (EST)*Organization*: Mathematics & Statistics, Univ. of Mass./Amherst*References*: <hic37h$5ef$1@smc.vnet.net> <201001111030.FAA23508@smc.vnet.net> <higdmv$kir$1@smc.vnet.net> <201001121016.FAA16958@smc.vnet.net>*Reply-to*: murray at math.umass.edu

Yes, that's more informative than the documentation extract I quoted -- although hardly complete and definitive. On 1/12/2010 5:16 AM, dh wrote: > Hi Murray, > > stright from the manual: > > "With the default setting ComplexityFunction->Automatic, forms are > > ranked primarily according to their LeafCount, with corrections to treat > > integers with more digits as more complex." > > Daniel > > > > Murray Eisenberg wrote: > >> Mathematica 7 documentation does NOT say that LeafCount is the criterion > >> for determining simplicity, that is, the default value of > >> ComplexityFunction. Rather it says: > >> > >> "The default ComplexityFunction counts the subexpressions and digits > >> of integers." > >> > >> But it does not even say how it combines the counts of the number of > >> subexpressions and digits of integers! > >> > >> On 1/11/2010 5:30 AM, dh wrote: > >>> Hi, > >>> > >>> why do you think x(x^2 y^3)^(1/4) is simpler than (x^6 y^3)^(1/4)? > >>> > >>> Mathematica needs some criterion for this decision. The default criterion is the > >>> > >>> "LeafCount[..]". If that does not suit you, you must define another > >>> > >>> criterion. > >>> > >>> Daniel > >>> > >>> > >>> > >>> francix wrote: > >>> > >>>> Hi, > >>>> I am using Matematica 7 and need some help with Radicals. > >>>> If I do > >>>> Simplify[(x^4 y^3)^(1/4), x>= 0] I correctly have > >>>> x (y^3)^(1/4) > >>>> But If I do > >>>> Simplify[(x^6 y^3)^(1/4), x>= 0] I get > >>>> (x^6 y^3)^(1/4) and not the correct answer x(x^2 y^3)^(1/4) > >>>> Thanks in advanced. > >>> > >>> > >> > > > -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305

**References**:**Re: Radicals simplify***From:*dh <dh@metrohm.com>

**Re: Radicals simplify***From:*dh <dh@metrohm.com>