Hi All,
I’m trying to solve the inverse problem of Sping Mass ODE.
The system is shown in the following figure.
It shows one mass attached to each other by two springs. It is a easier verion from the User Guide example.(Coupled Spring Mass ODE System)
I assume the following conditions:
x(0)=1、x'(0)=0、[k_1, k_2]=[2, 2]、m=1 (Ground Truth)
I utilize general solution 𝑥(𝑡)=𝐴cos(𝜔𝑡) of the sping mass system as an input to the PINNs whose job is to predict the m of the mass.
When using the PointwiseConstraint in Modulus Sym to create constraints from data, I encounter a problem:
Accorgind to the document from PointwiseConstraint.from_numpy, the invar and outvar must be (N, 1).
So I can not add the x'(0)=0 constraint with this function.
Is there any function avaiable to add (1,) shape constraint ?
Take the following figure for example, and the t is from 0~10 second:
Thanks!
Evian Chen