Decision Optimization

Can you please take a look at this code and help me understand why I am getting the errors below and how to fix them?

int CandidateSites = 13; //Number of candidate locations for SVMs
int Communities = 7; //Number of communities

range CandidateSitesRange = 1..CandidateSites;
range CommunitiesRange = 1..Communities;

// Now we define the parameters
{float} Smax=...;    // Max distance a person is willing to travel
{float} B=...;        // Budget
{float} Q1=...;        // Qaly gained from overdose reversal
{float} Q2=...;        // Qaly gained from referral
{float} lambda=...;    // Rate of reduction in willingness wot travel
{float} Bth=...;    // Accessability score threshold

{int} NR[CandidateSitesRange]=...;        // Number of restocks at each location
{float} l[CandidateSitesRange]=...;        // Probability of a refferal
{int} K[CandidateSitesRange]=...;        // SVM capacity
{float} C1[CandidateSitesRange]=...;    // Cost per restock for SVM at location i
{float} C2[CandidateSitesRange]=...;    // Annualized fixed cost, plus maintenance cost for SVM at location i
{float} C3[CandidateSitesRange]=...;    // Cost per dose of naloxone at location i

{float} q[CommunitiesRange]=...;    // Probability a dose is used for overdose reversal
{int} Demand[CommunitiesRange]=...; // Demand at a commuinity
{float} f[CommunitiesRange]=...;    // Fraction of demand that has OUD

{float} s[CommunitiesRange][CandidateSitesRange] = ...; // Distance between community j and SVM location i
{float} p[CommunitiesRange][CandidateSitesRange] = ...;    // probability one would travel from community to location i

// Define decision variables
dvar boolean Z[CandidateSitesRange];
dvar int d[CommunitiesRange][CandidateSitesRange];
dvar float n[CommunitiesRange];

// Objective function
 dexpr float SVM = Q1*(sum(j in CommunitiesRange, i in CandidateSitesRange)q[j]*n[j]*d[j][i]) + Q2*(sum(j in CommunitiesRange, i in CandidateSitesRange)l[i]*f[j]*n[j]*d[j][i]);

 // Model
  maximize SVM;
 
  subject to{
  
  forall (j in CommunitiesRange)
    n[j] == 1;
  
  forall (j in CommunitiesRange, i in CandidateSitesRange)
    d[j][i] <= p[j][i]*Demand[j]*Z[i];
  
  forall (j in CommunitiesRange)
    sum(i in CandidateSitesRange) d[j][i] <= Demand[j];
    
  sum(i in CandidateSitesRange)((Z[i]*C2[i])+(C3[i]*sum(j in CommunitiesRange)d[j][i])+(C1[i]*sum(j in CommunitiesRange)d[j][i]/K[i])) <= B;
  
  forall (j in CommunitiesRange)
    sum(i in CandidateSitesRange) p[j][i]*Z[i] >= Bth;
    
  forall (i in CandidateSitesRange)
      sum(j in CommunitiesRange)d[j][i]/K[i] <= NR[i];
  
  forall (j in CommunitiesRange, i in CandidateSitesRange)
    d[j][i] >= 0;
    
  }

Errors:

Operator not available for {float} * {int}
Operator not available for {float} * dvar boolean
Operator not available for {float} * dvar float

Operator not available for dexpr int <= {int}

Operator not available for dvar boolean * {float}

Operator not available for dvar int / {int}

Hi,

you mix sets and scalar values.

Let me fix the objective to help you undestand.

dexpr float SVM =  first(Q1)*(sum(j in CommunitiesRange, i in CandidateSitesRange)first(q[j])*n[j]*d[j][i])  + first(Q2)*(sum(j in CommunitiesRange, i in CandidateSitesRange)first(l[i])*first(f[j])*n[j]*d[j][i]);

would work fine.

Q1 is a set. You can use an element of a set in an equation but not the set itself

regards

Can you please take a look at this code and help me understand why I am getting the errors below and how to fix them?

int CandidateSites = 13; //Number of candidate locations for SVMs
int Communities = 7; //Number of communities

range CandidateSitesRange = 1..CandidateSites;
range CommunitiesRange = 1..Communities;

// Now we define the parameters
{float} Smax=...;    // Max distance a person is willing to travel
{float} B=...;        // Budget
{float} Q1=...;        // Qaly gained from overdose reversal
{float} Q2=...;        // Qaly gained from referral
{float} lambda=...;    // Rate of reduction in willingness wot travel
{float} Bth=...;    // Accessability score threshold

{int} NR[CandidateSitesRange]=...;        // Number of restocks at each location
{float} l[CandidateSitesRange]=...;        // Probability of a refferal
{int} K[CandidateSitesRange]=...;        // SVM capacity
{float} C1[CandidateSitesRange]=...;    // Cost per restock for SVM at location i
{float} C2[CandidateSitesRange]=...;    // Annualized fixed cost, plus maintenance cost for SVM at location i
{float} C3[CandidateSitesRange]=...;    // Cost per dose of naloxone at location i

{float} q[CommunitiesRange]=...;    // Probability a dose is used for overdose reversal
{int} Demand[CommunitiesRange]=...; // Demand at a commuinity
{float} f[CommunitiesRange]=...;    // Fraction of demand that has OUD

{float} s[CommunitiesRange][CandidateSitesRange] = ...; // Distance between community j and SVM location i
{float} p[CommunitiesRange][CandidateSitesRange] = ...;    // probability one would travel from community to location i

// Define decision variables
dvar boolean Z[CandidateSitesRange];
dvar int d[CommunitiesRange][CandidateSitesRange];
dvar float n[CommunitiesRange];

// Objective function
 dexpr float SVM = Q1*(sum(j in CommunitiesRange, i in CandidateSitesRange)q[j]*n[j]*d[j][i]) + Q2*(sum(j in CommunitiesRange, i in CandidateSitesRange)l[i]*f[j]*n[j]*d[j][i]);

 // Model
  maximize SVM;
 
  subject to{
  
  forall (j in CommunitiesRange)
    n[j] == 1;
  
  forall (j in CommunitiesRange, i in CandidateSitesRange)
    d[j][i] <= p[j][i]*Demand[j]*Z[i];
  
  forall (j in CommunitiesRange)
    sum(i in CandidateSitesRange) d[j][i] <= Demand[j];
    
  sum(i in CandidateSitesRange)((Z[i]*C2[i])+(C3[i]*sum(j in CommunitiesRange)d[j][i])+(C1[i]*sum(j in CommunitiesRange)d[j][i]/K[i])) <= B;
  
  forall (j in CommunitiesRange)
    sum(i in CandidateSitesRange) p[j][i]*Z[i] >= Bth;
    
  forall (i in CandidateSitesRange)
      sum(j in CommunitiesRange)d[j][i]/K[i] <= NR[i];
  
  forall (j in CommunitiesRange, i in CandidateSitesRange)
    d[j][i] >= 0;
    
  }

Errors:

Operator not available for {float} * {int}
Operator not available for {float} * dvar boolean
Operator not available for {float} * dvar float

Operator not available for dexpr int <= {int}

Operator not available for dvar boolean * {float}

Operator not available for dvar int / {int}