Re: Help with old Mathematica file

*To*: mathgroup at smc.vnet.net*Subject*: [mg119962] Re: Help with old Mathematica file*From*: Patrick Scheibe <pscheibe at trm.uni-leipzig.de>*Date*: Sat, 2 Jul 2011 05:00:43 -0400 (EDT)*References*: <201107010850.EAA28408@smc.vnet.net>

Hi, in line 26 and 27 you try to find a minimum of a function z and you are starting at t=0 which is a maximum. There, the derivative is zero and FindMinimum doesn't know where to walk. Try setting FindMinimum[z, {t, 0.01, 0, b trif}] and don't try to adapt the programming style of this book, please. Cheers Patrick On Fri, 2011-07-01 at 04:50 -0400, Zsolt Ero wrote: > I am trying to solve a problem, for what I finally found a book what has some Mathematica files supplied, but I am stuck now as I cannot run the file. > > My problem is that I cannot run the program as it is written in Mathematica 3.0 and I don't know what should I change to make it run under today's Mathematica versions. Here is the error it returns. > > > FindMinimum::fmgz: Encountered a > > gradient that is effectively zero. The > > result returned may not be a minimum; > > it may be a maximum or a saddle point. > > The file is called Programs\MOTIPOIN.NB in this file: http://bit.ly/lMQh1K > > or alternatively, here is a pastebin for the code in question: http://pastebin.com/ASBXnVVS > > Can you have a look at what could be wrong with the code? Its only 50 lines, but I don't know how to fix it. >

**References**:**Help with old Mathematica file***From:*Zsolt Ero <zsolt.ero@gmail.com>