Compute the diagnostic. Regular (snapshot) quantity should be computed here; for rates of change, compute() should return the total change during the time step from t0 to t1. The rate itself is computed in evaluate_rate().
Implemented in pism::diagnostics::scalar::IceMassFluxAtGroundingLine, pism::diagnostics::scalar::IceMassFluxCalving, pism::diagnostics::scalar::IceMassFluxDischarge, pism::diagnostics::scalar::IceMassFluxConservationError, pism::diagnostics::scalar::IceMassFluxBasalFloating, pism::diagnostics::scalar::IceMassFluxBasalGrounded, pism::diagnostics::scalar::IceMassFluxSurface, pism::diagnostics::scalar::IceMassFluxBasal, pism::diagnostics::scalar::MaxHorizontalVelocity, pism::diagnostics::scalar::MaxDiffusivity, pism::diagnostics::scalar::TimeStepRatio, pism::diagnostics::scalar::TimeStepLength, pism::diagnostics::scalar::IceVolumeGlacierizedShelf, pism::diagnostics::scalar::IceVolumeGlacierizedGrounded, pism::diagnostics::scalar::IceAreaGlacierizedShelf, pism::diagnostics::scalar::IceAreaGlacierizedGrounded, pism::diagnostics::scalar::IceEnthalpy, pism::diagnostics::scalar::IceEnthalpyGlacierized, pism::diagnostics::scalar::IceAreaGlacierizedColdBase, pism::diagnostics::scalar::IceAreaGlacierizedTemperateBase, pism::diagnostics::scalar::IceVolumeCold, pism::diagnostics::scalar::IceVolumeGlacierizedCold, pism::diagnostics::scalar::IceVolumeTemperate, pism::diagnostics::scalar::IceVolumeGlacierizedTemperate, pism::diagnostics::scalar::IceMassRateOfChange, pism::diagnostics::scalar::IceMassRateOfChangeDueToFlow, pism::diagnostics::scalar::IceMassRateOfChangeGlacierized, pism::diagnostics::scalar::IceMass, pism::diagnostics::scalar::IceMassGlacierized, pism::diagnostics::scalar::IceMassNotDisplacingSeaWater, pism::diagnostics::scalar::IceAreaGlacierized, pism::diagnostics::scalar::IceVolumeRateOfChange, pism::diagnostics::scalar::IceVolumeRateOfChangeGlacierized, pism::diagnostics::scalar::SeaLevelRisePotential, pism::diagnostics::scalar::IceVolume, pism::diagnostics::scalar::IceVolumeGlacierized, pism::energy::LiquifiedIceFlux, pism::surface::diagnostics::TotalSurfaceRunoff, pism::surface::diagnostics::TotalSurfaceMelt, and pism::surface::diagnostics::TotalSurfaceAccumulation.
Referenced by pism::TSSnapshotDiagnostic::update_impl(), pism::TSRateDiagnostic::update_impl(), and pism::TSFluxDiagnostic::update_impl().