Prevent velocity Verlet integrator calculating the acceleration twice at each time step #1390
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YingboMa
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Apr 26, 2021
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| # x(t+Δt) = x(t) + v(t)*Δt + 1/2*a(t)*Δt^2 | ||
| ku = f.f1(duprev,uprev,p,t) | ||
| ku = integrator.fsallast.x[1] |
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I feel this should be integrator.fsallast.x[2]
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That leads to immediate divergence. I'm not sure I fully understand the variable naming scheme but in that function it seems ku is a(t) and kdu is a(t+dt). So once you reach the next step, you want to load kdu from the last step into the current ku.
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Thanks! |
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Thanks for the merge. |
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As discussed in #1387, use the FSAL value to avoid calculating the acceleration twice in the
VelocityVerletintegrator.Obtains similar results for a small system I tested on. I am running the package tests locally now.
Closes #1387.