On Wednesday, 22 October 2014 21:38:39 UTC-6, Mike wrote: > > I'd like to be able to do linear programming to arbitrary precision. The > documentation that I've found claims that both the glpk and PPL solvers > should do this, but I haven't been able to get either to work. > > As an example, the following code prints c to high precision, but the > solutions only to 12 digits. Where should I look for guidance? > Note: this seeks to maximize x+y given that 3x<=1 and 3y<=1, so the > solution is (1/3, 1/3) > > Mike M > > R=RealField(100) > c=Matrix(R, 2, 1, [-1, -1]) > G=Matrix(R, 2, 2, [3, 0, 0, 3]) > h=Matrix(R, 2, 1, [1, 1]) > print c # To check the precision being used by "print" > print > > sol=linear_program(c,G,h) > print sol['x'] > sol=linear_program(c,G,h, solver='glpk') > print sol['x'] > sol=linear_program(c,G,h, solver='PPL') > print sol['x'] > > My "straightforward" simplex method for teaching can handle this one correctly:
http://sagecell.sagemath.org/?z=eJxljUGLwjAQhe-F_oeHe0kgLa2ee60XhVL3JoukSdwOGxNJIui_31hkYRHeDLx58_HGbjTS9mSsZm3T8LJQ3V6mQHc2CqwFWoFjlVfVfuVw-z_MOm4EmkWb58P8TudZ2Gsgl6CAD3x6qNmoH6TZ4BqMokjeYTLkvnGLRmN6YLUAqxdYFmUxoMNuGIKfrLkcknRaBt37cGFbgbm2FBPjAqxS_GX-aof6TE7akyaVcpUMD8brSUZSp-jt7Xlj_BfTdE8X&lang=sage It can get pretty bad on degenerate problems, however, since it assumes all computations are exact even when they are not. Andrey -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
