Fwd: Mathematica 6.0 bug in computing MathieuC
- To: mathgroup at smc.vnet.net
- Subject: [mg80411] Fwd: [mg80300] Mathematica 6.0 bug in computing MathieuC
- From: "taoufik bakri" <t.bakri at gmail.com>
- Date: Tue, 21 Aug 2007 05:11:29 -0400 (EDT)
- References: <200708170544.BAA00089@smc.vnet.net>
Take the parameter c such that MathieuCharacteristicB[2, c]=1. One can easilty numerically compute c. We find c=- 6.433074585014675206670244658478726486156264965498297244484. Clearly, we have MathieuS(1,c,t) is Pi-periodic. However MathieuC(1,c,t) should oscillate but is NOT Pi-periodic. Moreover the Wronski-determinant ( i.e. MathieuS(1,c,t)*MathieuCPrime(1,c,t) - MathieuC(1,c,t)*MathieuSPrime(1,c,t)) is in this case time-independent and must be equal to -1. Mathematica 6.0does this all worng. You can check it yourself. Regards, T. Bakri On 8/17/07, Curtis Osterhoudt <cfo at lanl.gov> wrote: > > On Thursday 16 August 2007 23:44:27 taoufik bakri wrote: > > Dear all, > > Something is still worng with the algorithm behind computing MathieuC. > It > > reprts, for instance that MathieuC is pi-periodic when its not. I > noticed > > that people already (October 2006) reported similar problems with > version > > 5.2, yet version 6.0 still contains this bug!. Another CAS however > computes > > correctly both MathieuS and MathieuC. > > Regards, > > T. Bakri > > It might help if you gave an example of the error(s). I see nothing in the > documentation about MathieuC being pi-periodic (except for special values > of > its parameters), nor do various plots of the function lend support to this > > assertion. Where's the bug? > > -- > ========================================================== > 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:
- Mathematica 6.0 bug in computing MathieuC
- From: "taoufik bakri" <t.bakri@gmail.com>
- Mathematica 6.0 bug in computing MathieuC