import numpy as np
from gekko import GEKKO
m = GEKKO()
t = np.linspace(0,15,76)
m.time = t # 0.2 cycle time
u = m.MV(1,name='u')
x = m.CV(name='x')
y = m.CV(name='y')
m.Equations([5*x.dt() ==-x+1.5*u,\
             15*y.dt()==-y+3.0*u])