[ssc0109]

Hello everyone,
I am wondering how can I extract the residual of the solution?

I found some information from Residuals for convergence of segregated solvers

by using
lduMatrix::solverPerformance sp = solve(...
or
lduMatrix::solverPerformance sp = xEqn.solve();

however, it seems not working for OpenFoam/7.0 since it was a poster 14 years ago.

I tried
Foam:: solverPerformance sp = xEqn.solve();

it seems to work

but
Foam:: solverPerformance sp = solve(...)
does not work.

so what's the correct function should I call?

I am really appreciate for your help.

[ssc0109]

For people who meet the same problem,
I got the solution like:

vector Uresidual;
Uresidual = solve(UEqn == -fvc::grad(p)).initialResidual();


scalar presidual;
presidual = pEqn.solve().initialResidual();