TITLE: Software tools for medium-scale systems of polynomial equations
QUESTION [9 upvotes]: I am attempting to find all real solutions of a system of 12 polynomial equations in 12 unknowns. The equations each have total degree 6 and contain up to 1700 terms. I am only interested in real solutions. The equations were derived as the gradients of a sum-of-squares cost function, which I am attempting to find all global optima of. I believe there are a finite number of real solutions but I have not confirmed this yet. I have floating point coefficients and I'm looking for numerical solutions (as opposed to symbolic solutions).
Which software packages (and which functions specifically) are generally most promising to solve such a problem?
I am aware of various functions in Maple, Matlab, and Mathematica that can solve systems of polynomial equations but there are a large number of options in each software package and I'm interested in advice on where I should be looking first for problems of this scale.
A numerical dump of the cost function is here: 
https://raw.githubusercontent.com/alexflint/polygamy/master/out/epipolar_accel_bezier3/cost.txt

REPLY [6 votes]: In Maple you can just do 
with(Optimization):
g := (your function):
Minimize(g,iterationlimit = 200);

On my machine this takes only about 1.5 seconds to return the following:
[2.35579022955789696*10^(-9), 
[x0 = .696531801759957, x1 = .286105658731833, x10 = .342973444356395, 
 x11 = .728732510532874, x2 = .226824733028582, x3 = .551288843437034, 
 x4 = .719479494442298, x5 = .423120942717389, x6 = .980635895595386, 
 x7 = .684727337329935, x8 = .480773372241607, x9 = .391860913480735]]

If you ask for 30 digits of accuracy (so that Maple cannot just use hardware floats) then it gets a lot slower, but still only 40 seconds.
Incidentally, I tried this first as just Minimize(g), which gave me an answer with a warning that the maximum iteration limit had been reached.  The default limit is 50 iterations, so I tried 200 and the warning went away.
Also, there is another function called LSSolve which is specifically for the case where your objective function is a sum of squares.  I did not use that because I do not know how to express your objective in the relevant form.