Hello,
Thank you for the assistance on the previous problem, that issue has been
resolved.
I am trying to make some headway implementing sundials into my FEA code.
However, at the first requested time "tout", the solution is obviously
incorrect. I have implemented this algorithm in MATLAB with success, and am
seeing very different trends in the C++ implementation.
The drastic change in "y" appears to occur at the RHS function call on Line
2668 of covde.c in the CVNlsNewton() function. For example, I should expect
values of y around [.79 .77 .75] but instead CVode is returning something
like [101.78 100.2 100.2]. Definitely, a far cry from the values I expect
from my validated MATLAB code.
If needed, here are my setting and initializations. These are the same
settings I am using in my MATLAB implementation that has worked.
t0 = 0.0;
//y = N_VMake_Serial(totalNumDof,u_s);
y = N_VNew_Serial(totalNumDof);
abstol = N_VNew_Serial(totalNumDof);
ydot = N_VNew_Serial(totalNumDof);
reltol = 1e-4;
for (int i=0;i<totalNumDof;i++)
{
NV_Ith_S(y,i) = u_s[i];
NV_Ith_S(abstol,i) = reltol*100.0;
}
cvode_mem =
CVodeCreate(CV_BDF,CV_NEWTON);
flag = CVodeInit(cvode_mem,RHSfunction, t0, y);
flag = CVodeSVtolerances(cvode_mem, reltol, abstol);
flag = CVDense(cvode_mem, totalNumDof);
flag = CVodeSetUserData(cvode_mem,this);
Thanks,
Brian
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