Vfrdtyky

I tried to convert an example from gekko python optimizer by using the list, array x instead of variables x1..x4. This is the code which gives the result, but I think it is not correct

from gekko import GEKKO

import numpy as np

# Initialize Model

m = GEKKO(remote=False)



#help(m)



#define parameter

eq = m.Param(value=40)



#initialize variables

x = [m.Var(value=1,lb=1,ub=5) for i in range(4)]

x[1].value=5

x[2].value=5



#Equations

m.Equation(np.prod([x[i] for i in range(0,4)])>=25)

m.Equation(np.sum([x[i]**2 for i in range(0,4)])==eq)



#Objective

m.Obj(x[0]*x[3]*(x[0]+x[1]+x[2])+x[2])



#Set global options

m.options.IMODE = 3 #steady state optimization



#Solve simulation

m.solve() # solve on public server



#Results

print('')

print('Results')

print('x1: ' + str(x[0].value))

print('x2: ' + str(x[1].value))

print('x3: ' + str(x[2].value))

print('x4: ' + str(x[3].value))

Please anyone could help me out how to use list, array of variables in gekko. This seems to me less elegant and I was wondering is there is a way of using Array() function instead of Var(). I can not figure out how and when we can use Array() function.

This one will work as well.

#Equations

m.Equation(np.prod(np.asarray(x))>=25)

m.Equation(np.sum(np.asarray(x)**2)==eq)