How to pass multiple constraints in NLP solver

[Nitish Garg]

How to pass multiple inequality constraints to NLP solver?

I was trying the following code (error is shown below)

from casadi import SX, nlpsol

# Initialize problem

x = SX.sym('x', 2)

# Objective function

# Min: -(x^2 + y^2)

f = -(x[0]**2 + x[1]**2)

# Constraints

# x + y <= 10

# x <= 5

# 0 <= x,y <= 100

g = [ x[0] + x[1] , x[0] ]

solver_params = {

   "ubg": [10, 5],

   "lbx": [0, 0],

   "ubx": [100, 100],

   "x0": [2, 2]

}

# Solve

solver = nlpsol("solver", "ipopt", {'x':x, 'f':f, 'g':g}, {})

sol = solver(**solver_params)

# Print solution

print "-----"

print "objective at solution = ", sol["f"]

print "primal solution = ", sol["x"]

Below is the error I got on running the above code:

Traceback (most recent call last):

 File "casadi-test.py", line 22, in <module>

   solver = nlpsol("solver", "ipopt", {'x':x, 'f':f, 'g':g}, {})

 File "/u/gargnit/programming/casadi/pybuild/casadi/casadi.py", line 8416, in nlpsol

   return _casadi.nlpsol(*args)

NotImplementedError: Wrong number or type of arguments for overloaded function 'nlpsol'.

 Possible C/C++ prototypes are:

   casadi::nlpsol(std::string const &,std::string const &,casadi::SXDict const &,casadi::Dict const &)

   casadi::nlpsol(std::string const &,std::string const &,casadi::MXDict const &,casadi::Dict const &)

   casadi::nlpsol(std::string const &,std::string const &,std::string const &,casadi::Dict const &)

   casadi::nlpsol(std::string const &,std::string const &,casadi::Importer const &,casadi::Dict const &)

   casadi::nlpsol(std::string const &,std::string const &,casadi::NlpBuilder const &,casadi::Dict const &)

[Joris Gillis]

g = vertcat(constr1,constr2)