On Monday, June 23, 2014 3:55:51 AM UTC-4, Camille Chambon wrote: > > Hello Vinzent, > > It's exactly what I was looking for. Thanks! > > How do you choose the starting point? The coefficients (0.66, 0.34 and > 0.7) may vary. Is there a way to choose the right starting point > automatically? >
I'm not sure what you mean. Do you want multidimensional root finding? (I.e. do you want to find parameters for which the expression becomes zero?) Or do you want to find the root for various given coefficients? For multidimensional root finding sympy uses Newton's method, so it only works well if you know the approximate location of your root. There are algorithms that work for bad starting points implemented in scipy, you could use those to get an approximative solution and then refine the result to any precision you want using sympy. If you parameters are fixed, then you can try a lot of different starting points in an interval and merge the results. You could use one of the bisection-based solvers (see mpmath.findroot). Vinzent -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/070d16a1-2fff-43b3-8ac4-be0d8049eb20%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
