Display "no value" error for a computed parameter

[chaimaa...@gmail.com]

Hello,

I have a computed parameter which is a function of other parameters as well as some variables.

So I first declare it: 

       param beta{battery, panel, 1..T};  

And then after, I write its expression as a constraint:

       subject to beta_limits {b in battery, pv in panel, t in 1..T}: 

        beta[b,pv,t] = (if  (N_PV[pv,b] * G[pv,t] )- L[t]   < max (-(N_B[pv,b] * betamin[b]) , (N_B[pv,b] * Cmin[b] - SE[b,pv,t]) * n_dis[b]) then 0

    else

(if  (N_PV[pv,b] * G[pv,t] )- L[t]  >  min ( betamax[b] * N_B[pv,b] , (N_B[pv,b] * Cmax[b] - SE[b,pv,t]) / n_char[b])  then min ( betamax[b] * N_B[pv,b] , (N_B[pv,b] * Cmax[b] - SE[b,pv,t]) / n_char[b])

 else (N_PV[pv,b] * G[pv,t] )- L[t] 

)

  );

I note that all the elements here are parameters except:

        N_PV[pv,b], N_B[pv,b] which are variables, and

        SE[b,pv,t] which is a computed parameter having variables in its expression.

(to not complicate things more, I attached the two files .mod and .dat of my problem to have clearer idea)

When trying to solve the model, I get the error: 

           

                   Error executing "objective" command:

                   error processing objective total_cost['pv1','b1']:

           no value for beta['b1','pv1',1]

Can anyone help me with that please?

Thank you in advance.