def test_ecos_leastsquares():
x = cvx.Variable (name='x')
F = cvx.Parameter(name='F')
g = cvx.Parameter(name='g')
objective = cvx.square(cvx.norm( F*x - g ))
objective = cvx.Minimize(objective)
problem = cvx.Problem(objective, [])
canon = Canonicalize(problem, verbose=True)
# Set values of parameters
parameters = {
'F' : 42,
'g' : 42,
}
canon.assign_values(parameters)
solution = cvx.solve(canon, verbose = True)
if solution:
print('Solution obj:', solution['info']['pcost'])
print('Solution x:', solution['x'][0])
assert( np.isclose(solution['x'][0], 1.0) )
reset_symbols()
def test_ecos_polyhedradist():
import cvx_sym as cvx
n = 2 # number of dimensions
m = 3 # number of lines defining polyhedron 1
p = 3 # number of lines defining polyhedron 2
x1 = cvx.Variable ((n,1),name='x1')
x2 = cvx.Variable ((n,1),name='x2')
A1 = cvx.Parameter((m,n),name='A1')
A2 = cvx.Parameter((p,n),name='A2')
B1 = cvx.Parameter((m,1),name='B1')
B2 = cvx.Parameter((p,1),name='B2')
objective = cvx.square(cvx.norm(x1 - x2))
constraints = [ A1[i,:].T * x1 <= B1[i] for i in range(m) ]
constraints += [ A2[i,:].T * x2 <= B2[i] for i in range(p) ]
objective = cvx.Minimize(objective)
problem = cvx.Problem(objective, constraints)
canon = Canonicalize(problem, verbose=True)
# Set values of parameters
parameters = {
'A1' : np.array([[-1,1],[1,1],[0,-1]]),
'B1' : np.array([[3],[3],[0]]),
'A2' : np.array([[.5,-1],[0,1],[+1,0]]),
'B2' : np.array([[-3],[3],[5]]),
}
canon.assign_values(parameters)
solution = cvx.solve(canon, verbose = True)
if solution:
print('Solution obj:', solution['info']['pcost'])
# Gather the OG solution variables
v_indices = [n for n, vn in enumerate(canon.vars.keys()) if 'x' in vn]
x_solution = [solution['x'][i] for i in v_indices]
print('Solution x:', x_solution)
print('Solution vec:', solution['x'])
# Solution is found at intersection of polyhedra
assert( np.allclose(x_solution, [0,3, 0,3], atol=1e-4) )
# So therefore the objective should be near zero
assert( np.allclose(solution['info']['pcost'], 0.0 ) )
reset_symbols()
def test_ecos_robustlp():
import cvx_sym as cvx
n = 2 # number of dimensions
m = 3 # number of elementwise elements
x = cvx.Variable ((n,1),name='x')
A = cvx.Parameter((m,n),name='A')
B = cvx.Parameter((m,1),name='B')
C = cvx.Parameter((n,1),name='C')
P = cvx.Parameter((m,n),name='P')
objective = C.T * x
constraints = [A[i].T * x + cvx.norm(P[i].T * x) <= B[i] for i in range(m)]
objective = cvx.Minimize(objective)
problem = cvx.Problem(objective, constraints)
canon = Canonicalize(problem, verbose=True)
# Set values of parameters
parameters = {
'A' : np.array([[1,1],[1,1],[1,1]]),
'B' : np.array([[3],[3],[3]]),
'C' : np.array([[.1],[.2]]),
'P' : np.array([[1,2],[3,4],[5,6]])
}
canon.assign_values(parameters)
solution = cvx.solve(canon, verbose = True)
if solution:
print('Solution obj:', solution['info']['pcost'])
# Gather the OG solution variables
v_indices = [n for n, vn in enumerate(canon.vars.keys()) if 'x' in vn]
x_solution = [solution['x'][i] for i in v_indices]
print('Solution x:', x_solution)
print('Solution vec:', solution['x'])
assert( np.allclose(x_solution, [3,-3] ) )
reset_symbols()
def test_ecos_chebyshevcenter():
import cvx_sym as cvx
n = 2
m = 3
r = cvx.Variable((1,1),name='r')
x = cvx.Variable((n,1),name='x')
A = cvx.Parameter((m,n),name='A')
B = cvx.Parameter((m,1),name='B')
objective = -r
constraints = [A[i,:].T * x + r * cvx.norm(A[i,:]) <= B[i] for i in range(m)]
constraints += [r >= 0]
objective = cvx.Minimize(objective)
problem = cvx.Problem(objective, constraints)
canon = Canonicalize(problem, verbose=True)
# Set values of parameters
parameters = {
'A' : np.array([[-1,1],[1,1],[0,-1]]),
'B' : np.array([[3],[3],[0]]),
}
canon.assign_values(parameters)
solution = cvx.solve(canon, verbose = True)
if solution:
print('Solution obj:', solution['info']['pcost'])
# Gather the OG solution variables
v_indices = [n for n, vn in enumerate(canon.vars.keys()) if 'x' in vn]
x_solution = [solution['x'][i] for i in v_indices]
print('Solution x:', x_solution)
print('Solution vec:', solution['x'])
assert( np.allclose(x_solution, [0, 1.242641] ) )
reset_symbols()
def test_ecos_leastsquares_constr():
x = cvx.Variable ((3,1),name='x')
F = cvx.Parameter((3,3),name='F')
g = cvx.Parameter((3,1),name='g')
U = cvx.Parameter((3,1),name='U')
L = cvx.Parameter((3,1),name='L')
constraints = []
objective = cvx.square(cvx.norm( F*x - g ))
constraints += [ x <= U ]
constraints += [ L <= x ]
objective = cvx.Minimize(objective)
problem = cvx.Problem(objective, constraints)
canon = Canonicalize(problem, verbose=True)
# Set values of parameters
parameters = {
'F' : np.array([[1,2,3],[4,5,6],[7,8,9]]),
'g' : np.array([[1],[2],[3]]),
'U' : np.array([[42],[42],[42]]),
'L' : np.array([[1],[2],[3]])
}
canon.assign_values(parameters)
solution = cvx.solve(canon, verbose = True)
if solution:
print('Solution obj:', solution['info']['pcost'])
# Gather the OG solution variables
v_indices = [n for n, vn in enumerate(canon.vars.keys()) if 'x' in vn]
x_solution = [solution['x'][i] for i in v_indices]
print('Solution x:', x_solution)
print('Solution vec:', solution['x'])
assert( np.allclose(x_solution, [1,2,3] ) )
reset_symbols()
def test_ecos_trivial_norm1():
x = cvx.Variable((3,1),name='x')
constraints = [x >= -1]
constraints += [x <= +1]
objective = cvx.norm(x, kind=1)
objective = cvx.Minimize(objective)
problem = cvx.Problem(objective, constraints)
canon = Canonicalize(problem, verbose=True)
canon.assign_values({})
solution = cvx.solve(canon, verbose = True)
if solution:
print('Solution obj:', solution['info']['pcost'])
print('Solution x:', solution['x'])
assert( np.allclose(solution['x'][0:3], [0.0, 0.0, 0.0]) )
reset_symbols()
def __init__(self):
K = 50
self.Xv = cvx.Variable((K, 14), name='Xv')
self.Uv = cvx.Variable((K, 14), name='Uv')
self.nuv = cvx.Variable((14 * (K - 1)), name='nuv')
self.delta = cvx.Variable(K, name='delta')
self.sigmav = cvx.Variable(name='sigmav')
self.delta_sv = cvx.Variable(name='delta_sv')
self.x_init = cvx.Parameter((1, 14), name='x_init')
self.x_final = cvx.Parameter((1, 14), name='x_final')
# Indexes to expect config variables on
m_dry = 0
tan_gamma_gs = 1
cos_theta_max = 2
cos_delta_max = 3
w_B_max = 4
T_min = 5
T_max = 6
self.config = cvx.Parameter((7), name='config')
# Parameters:
self.A_bar_parm = cvx.Parameter((K, 14 * 14), name='A_bar_parm')
self.B_bar_parm = cvx.Parameter((K, 14 * 3), name='B_bar_parm')
self.C_bar_parm = cvx.Parameter((K, 14 * 3), name='C_bar_parm')
self.S_bar_parm = cvx.Parameter((K, 14), name='S_bar_parm')
self.z_bar_parm = cvx.Parameter((K, 14), name='z_bar_parm')
self.X_last_parm = cvx.Parameter((K, 14), name='X_last_parm')
self.U_last_parm = cvx.Parameter((K, 14), name='U_last_parm')
self.s_last_parm = cvx.Parameter(name='s_last_parm')
self.w_delta_parm = cvx.Parameter(name='w_delta_parm')
self.w_nu_parm = cvx.Parameter(name='w_nu_parm')
self.w_delta_sigma_parm = cvx.Parameter(name='w_delta_sigma_parm')
""" The start/end indexes of each variable in the vector V = XABCSz """
self.idx = [14] # end of x (14,1)
self.idx += [self.idx[0] + (14 * 14)] # end of A (14,14)
self.idx += [self.idx[1] + (14 * 3)] # end of B (14,3)
self.idx += [self.idx[2] + (14 * 3)] # end of C (14,3)
self.idx += [self.idx[3] + (14 * 1)] # end of S (14,1)
self.idx += [self.idx[4] + (14 * 1)] # end of z (14,1)
self.constraints = []
# ----------------------------------------------------- Dynamics:
for k in range(K - 1):
self.constraints += [
self.Xv[k +
1, :] == (cvx.reshape(self.A_bar_parm[k, :],
(14, 14)) * self.Xv[k, :] +
cvx.reshape(self.B_bar_parm[k, :],
(14, 3)) * self.Uv[k, 0:3] +
cvx.reshape(self.C_bar_parm[k, :],
(14, 3)) * self.Uv[k + 1, 0:3] +
self.S_bar_parm[k, :] * self.sigmav +
self.z_bar_parm[k, :] +
self.nuv[k * 14:(k + 1) * 14])
]
# ----------------------------------------------------- State constraints:
self.constraints += [self.Xv[:, 0] >= self.config[m_dry]]
for k in range(K):
self.constraints += [
self.config[tan_gamma_gs] * cvx.norm(self.Xv[k, 2:4]) <=
self.Xv[k, 1], self.config[cos_theta_max] <=
1 - 2 * cvx.sum_squares(self.Xv[k, 9:11]),
cvx.norm(self.Xv[k, 11:14]) <= self.config[w_B_max]
]
# ------------------------------------------------- Control constraints:
#B_g = self.U_last_parm[k, 0:3] / cvx.norm(self.U_last_parm[k, 0:3])
self.constraints += [
# self.config[T_min] <= B_g * self.Uv[k, 0:3].T,
self.Uv[k, 0] >= 0,
cvx.norm(self.Uv[k, 0:3]) <= self.config[T_max],
self.config[cos_delta_max] * cvx.norm(self.Uv[k, 0:3]) <=
self.Uv[k, 0]
]
# ------------------------------------------------- Trust regions:
dx = self.Xv[k, :] - self.X_last_parm[k, :]
du = self.Uv[k, :] - self.U_last_parm[k, :]
self.constraints += [
cvx.sum_squares(dx) + cvx.sum_squares(du) <= self.delta[k]
]
self.constraints += [
cvx.norm(self.sigmav - self.s_last_parm) <= self.delta_sv
]
self.constraints += [self.sigmav >= 0]
self.constraints += [
self.Xv[0, 0:7] == self.x_init[0, 0:7], # init all but attitude
self.Xv[0, 11:14] == self.x_init[0, 11:14],
self.Xv[K - 1, 1:14] == self.x_final[0,
1:14], # final all but mass
self.Uv[K - 1, 1] == 0,
self.Uv[K - 1, 2] == 0,
]
objective = cvx.Minimize(self.sigmav # minimize flight time
#-Xv[-1,0] # minimize fuel use
# virtual control
+ self.w_nu_parm * cvx.norm(self.nuv, kind=1)
# trust region on dynamics
+ self.w_delta_parm * cvx.norm(self.delta)
# trust region on sigma
+ self.w_delta_sigma_parm *
cvx.norm(self.delta_sv, kind=1))
self.problem = cvx.Problem(objective, self.constraints)
gen = cvx.Generate(
self.problem,
name='Aeroland_core',
folder='raw',
verbose=2 # show each stage of the process
)
import cvx_sym as cvx
import numpy as np
'''
Least squares optimization problem
'''
x = cvx.Variable(name='x')
F = cvx.Parameter(name='F')
g = cvx.Parameter(name='g')
constraints = []
objective = cvx.square(cvx.norm(F * x - g))
objective = cvx.Minimize(objective)
problem = cvx.Problem(objective, constraints)
generator = cvx.Generate(problem,
name='least_squares_unconstr',
folder='integrated_projects',
verbose=True)
def full_scale_ecos_control():
""" Takes a long time to canonicalize, so don't run as routine test """
import cvx_sym as cvx
n = 8
m = 2
T = 50
x = cvx.Variable((n, T+1), name='x')
u = cvx.Variable((m, T), name='u')
x_0 = cvx.Parameter((n,1), name='x_0')
A = cvx.Parameter((n,n), name='A')
B = cvx.Parameter((n,m), name='B')
states = []
constraints = [ x[:,T] == 0 ]
constraints += [ x[:,0] == x_0[:,0] ]
for t in range(T):
constraints += [ x[:,t+1] == A*x[:,t] + B*u[:,t] ]
constraints += [ cvx.norm(u[:,t], kind = 'inf') <= 1 ]
cost = cvx.sum_squares(x[:,t+1]) + cvx.sum_squares(u[:,t])
states.append( cost )
# sums problem objectives and concatenates constraints.
objective = cvx.sum(states)
objective = cvx.Minimize(objective)
problem = cvx.Problem(objective, constraints)
canon = Canonicalize(problem, verbose = 1 )
np.random.seed(1)
alpha = 0.2
beta = 5
A_set = np.eye(n) + alpha*np.random.randn(n,n)
B_set = np.random.randn(n,m)
x_0_set = beta*np.random.randn(n,1)
# Set values of parameters
parameters = {
'A' : A_set,
'B' : B_set,
'x_0' : x_0_set,
}
canon.assign_values(parameters)
solution = cvx.solve(canon, verbose = True)
if solution:
obj = solution['info']['pcost']
# Gather the OG solution variables
v_indices = [n for n, vn in enumerate(canon.vars.keys()) if 'x' in vn]
x_solution = [solution['x'][i] for i in v_indices]
print('Solution obj:', obj)
print('Solution x:', x_solution)
print('Solution vec:', solution['x'])
assert( np.isclose(obj, 64470.59019495451) )
reset_symbols()
import cvx_sym as cvx
n = 2 # number of dimensions
m = 3 # number of lines defining polyhedron 1
p = 3 # number of lines defining polyhedron 2
x1 = cvx.Variable((n, 1), name='x1')
x2 = cvx.Variable((n, 1), name='x2')
A1 = cvx.Parameter((m, n), name='A1')
A2 = cvx.Parameter((p, n), name='A2')
B1 = cvx.Parameter((m, 1), name='B1')
B2 = cvx.Parameter((p, 1), name='B2')
objective = cvx.square(cvx.norm(x1 - x2))
constraints = [A1[i].T * x1 <= B1[i] for i in range(m)]
constraints += [A2[i].T * x2 <= B2[i] for i in range(p)]
objective = cvx.Minimize(objective)
problem = cvx.Problem(objective, constraints)
generator = cvx.Generate(problem,
name='polyhedradist',
folder='integrated_projects',
verbose=1)
x = cvx.Variable((n, T+1), name='x')
u = cvx.Variable((m, T), name='u')
x_0 = cvx.Parameter((n), name='x_0')
A = cvx.Parameter((n,n), name='A')
B = cvx.Parameter((n,m), name='B')
states = []
constraints = [ x[:,T] == 0 ]
constraints += [ x[:,0] == x_0[:,0] ]
for t in range(T):
constraints += [ x[:,t+1] == A*x[:,t] + B*u[:,t] ]
constraints += [ cvx.norm(u[:,t], kind = 'inf') <= 1 ]
cost = cvx.sum_squares(x[:,t+1]) + cvx.sum_squares(u[:,t])
states.append( cost )
# sums problem objectives and concatenates constraints.
objective = cvx.sum(states)
objective = cvx.Minimize(objective)
problem = cvx.Problem(objective, constraints)
problem = cvx.Problem(objective, constraints)
generator = cvx.Generate(problem, name = 'control',
folder = 'integrated_projects',
verbose = 1)
import cvx_sym as cvx
n = 2 # number of dimensions
m = 3 # number of elementwise elements
x = cvx.Variable((n, 1), name='x')
A = cvx.Parameter((m, n), name='A')
B = cvx.Parameter((m, 1), name='B')
C = cvx.Parameter((n, 1), name='C')
P = cvx.Parameter((m, n), name='P')
objective = C.T * x
constraints = [A[i].T * x + cvx.norm(P[i].T * x) <= B[i] for i in range(m)]
objective = cvx.Minimize(objective)
problem = cvx.Problem(objective, constraints)
generator = cvx.Generate(problem,
name='robustlp_socp',
folder='integrated_projects',
verbose=1)
import cvx_sym as cvx
n = 2
m = 3
r = cvx.Variable((1, 1), name='r')
x = cvx.Variable((n, 1), name='x')
A = cvx.Parameter((m, n), name='A')
B = cvx.Parameter((m, 1), name='B')
objective = -r
constraints = [A[i, :].T * x + r * cvx.norm(A[i, :]) <= B[i] for i in range(m)]
constraints += [r >= 0]
objective = cvx.Minimize(objective)
problem = cvx.Problem(objective, constraints)
generator = cvx.Generate(problem,
name='chebyshevcenter',
folder='integrated_projects',
verbose=1)