jump-dev / SumOfSquares.jl

Sum of Squares Programming for Julia
Other
115 stars 24 forks source link

Formulating trigonometric functions within SOS #252

Closed jediofgever closed 2 years ago

jediofgever commented 2 years ago

Hi, I am trying to obtain a candidate Lyapunov function for a dynamical system. However in the state dynamics I have trigonometric functions such as sin and cos. I wonder whether it is possible to handle this cases while formulating SOS, I cant see an example of such case and will highly appreciate if you could help. Thank you.

blegat commented 2 years ago

It is sometimes possible by doing the change of variables sin(a) = x, cos(a) = y and adding x^2 + y^2 == 1 in the domain.

jediofgever commented 2 years ago

Thank you @blegat