Main

## APM.ICD_CALC - APMonitor Option

 Type: Integer, Input
Default Value: 0
Description: Specifications for initial condition differentials
MHE only (IMODE=5 or 8): 0=OFF, 1=ON


ICD_CALC is an option for the initial conditions that are associated with differential variables in estimation applications (IMODE=5 or 8). When ICD_CALC=1 (ON), the algebraic variables remain fixed at current values but the differential variables become adjustable by the solver. Any value in the time horizon can be fixed or calculated by setting FIXED or CALCULATED in a CONNECTIONS section of the model. The ICD_CALC option is typically used when estimation problems have uncertain initial conditions, especially during initialization. Leaving ICD_CALC=1 (ON), may reduce the predictive capability of a model to check for conservation of mass or energy because the differential equations are not enforced for the initial conditions.