residential/solvers.cpp

#define USE_GLSOLVERS
#include "gridlabd.h"

#ifdef USE_NEWSOLVER

double a=0,n=0,b=0,m=0,c=0;

double ft(double t)
{
    return a*exp(t*n) + b*exp(t*m) + c;
}
double dfdt(double t)
{
    return a*n*exp(t*n) + b*m*exp(t*m);
}
double e2solve(double _a, double _n, double _b, double _m, double _c, double p, double *e)
{
    static glsolver *newton_method = NULL;
    static struct {
        unsigned int n; // dimensions (default 1)
        double *x; // current values of x
        double (**f)(double); // functions
        double (**df)(double); // derivatives
        double *p; // precision
        unsigned int *m; // multiplicities (default is 1)
        unsigned char *s; // status (0=failed, 1=converge, 2=non-converged)
    } data;

    // load the solver if not yet loaded
    if ( newton_method==NULL )
    {
        newton_method = new glsolver("newton_method");
        unsigned int version=0;
        if ( newton_method->get("version",&version,NULL)==0 || version!=1 )
            throw "newton_method version incorrect";
        if ( newton_method->set("dimensions",1,NULL)==0 )
            throw "newton_method dimensions can't be set";
        if ( newton_method->get("init",&data,NULL)==0 )
            throw "newton_method data can't be obtained";
        data.f[0] = ft;
        data.df[0] = dfdt;
    }

    // solve it
    data.x[0] = 0.0;
    data.p[0] = p;
    a=_a; b=_b; c=_c; n=_n; m=_m; 
    if ( newton_method->solve(&data) )
    {
        if ( e!=NULL )
            *e = data.x[0] / dfdt(data.x[0]);
        return data.x[0];
    }
    else
        return NaN;
}

#else

double e2solve(double a, double n, double b, double m, double c, double p, double *e)
{
    // load the solver if not yet loaded
    static glsolver *etp = NULL;
    static struct etpdata {
        double t,a,n,b,m,c,p,e;
        unsigned int i;
    } data;
    if ( etp==NULL )
    {
        etp = new glsolver("etp");
        int version;
        if ( etp->get("version",&version,NULL)==0 || version!=1 )
            throw "incorrect ETP solver version";
        if ( etp->get("init",&data,NULL)==0 )
            throw "unable to initialize ETP solver data";
        data.i = 100;
    }

    // solve it
    data.t = 0;
    data.a = a;
    data.b = b;
    data.c = c;
    data.n = n;
    data.m = m;
    data.p = p;
    if ( etp->solve(&data) )
    {
        if ( e!=NULL )
            *e = data.e;
        return data.t;
    }
    else
        return NaN;
}

#endif

---

GridLAB-D™ Version 4.1

An open-source smart grid simulator created by PNNL for the US Department of Energy Office of Electricity