// define the indices
BUS_I       = 1;    // bus number (1 to 29997)
BUS_TYPE    = 2;    // bus type (1 - PQ bus, 2 - PV bus, 3 - reference bus, 4 - isolated bus)
PD          = 3;    // Pd, real power demand (MW)
QD          = 4;    // Qd, reactive power demand (MVAr)
GS          = 5;    // Gs, shunt conductance (MW at V = 1.0 p.u.)
BS          = 6;    // Bs, shunt susceptance (MVAr at V = 1.0 p.u.)
BUS_AREA    = 7;    // area number, 1-100
VM          = 8;    // Vm, voltage magnitude (p.u.)
VA          = 9;    // Va, voltage angle (degrees)
BASE_KV     = 10;   // baseKV, base voltage (kV)
ZONE        = 11;   // zone, loss zone (1-999)
VMAX        = 12;   // maxVm, maximum voltage magnitude (p.u.)      (not in PTI format)
VMIN        = 13;   // minVm, minimum voltage magnitude (p.u.)      (not in PTI format)

// included in opf solution, not necessarily in input
// assume objective function has units, u
LAM_P       = 14;   // Lagrange multiplier on real power mismatch (u/MW)
LAM_Q       = 15;   // Lagrange multiplier on reactive power mismatch (u/MVAr)
MU_VMAX     = 16;   // Kuhn-Tucker multiplier on upper voltage limit (u/p.u.)
MU_VMIN     = 17;   // Kuhn-Tucker multiplier on lower voltage limit (u/p.u.)