Feasible with conopt3 but not conop4
Posted: Wed Nov 24, 2021 8:26 pm
Dear all,
The model I currently use is feasible with conopt3 but not conopt4 "An equation in the pre-triangular part of the model cannot be solved because there are no non-fixed variables left".
Basically, the concentration of several GHG (let call them HFCxx) depend on the concentration of OH, on the emission level of the timestep, and on past year concentration. We deduce from the HFCxx concentration a radiative forcing RAD, they are linearly related (equation RADHALQ .. RAD(T,HFCxx) =e= RHO(HFCxx)*CON(T,HFCxx), RHO beiing a parameter). the emission levels are externally prescribed, as well as initial concentration.
I identified the equation that causes this problem, thanks to the solution reporting : the RADHALQ equation fixes two variables at once, and I do not know why, as both variables are far from their bound.
Variable CON(2002,HFC245ca) is forced to its current value = 0.47563
Variable RAD(2002,HFC245ca) is forced to its current value = 0.0109395
Equation RADHALQ(2002,HFC245ca) acting as binding =G= has forced the above variables
Did someone ever encountered this problem with conopt4?
Thanks,
Yann
The model I currently use is feasible with conopt3 but not conopt4 "An equation in the pre-triangular part of the model cannot be solved because there are no non-fixed variables left".
Basically, the concentration of several GHG (let call them HFCxx) depend on the concentration of OH, on the emission level of the timestep, and on past year concentration. We deduce from the HFCxx concentration a radiative forcing RAD, they are linearly related (equation RADHALQ .. RAD(T,HFCxx) =e= RHO(HFCxx)*CON(T,HFCxx), RHO beiing a parameter). the emission levels are externally prescribed, as well as initial concentration.
I identified the equation that causes this problem, thanks to the solution reporting : the RADHALQ equation fixes two variables at once, and I do not know why, as both variables are far from their bound.
Variable CON(2002,HFC245ca) is forced to its current value = 0.47563
Variable RAD(2002,HFC245ca) is forced to its current value = 0.0109395
Equation RADHALQ(2002,HFC245ca) acting as binding =G= has forced the above variables
Did someone ever encountered this problem with conopt4?
Thanks,
Yann