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import numpy as np
import matplotlib.pyplot as plt
from scipy.linalg import solve_continuous_lyapunov as clyap
from scipy.linalg import svd
# --> Utility function.
vec2array = lambda x, ny, nz : x.reshape(ny, nz)
array2vec = lambda x : x.flatten()
# --> Differential operators.
@loiseaujc
loiseaujc / LQE.ipynb
Last active January 31, 2024 09:07
Notebook for the control class on the Kalman filter
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@loiseaujc
loiseaujc / LQR.ipynb
Last active November 5, 2024 11:12
Notebook for the control class on Linear Quadratic Regulator
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using StructuredOptimization
"""
Simple implementation of basis pursuit denoising using StructuredOptimization.jl
INPUT
-----
C : The measurement matrix.
Ψ : Basis in which x is assumed to be sparse.
y : Pixel measurements.
λ : (Optional) Sparsity knob.
@loiseaujc
loiseaujc / optimized_bpdn.jl
Created February 17, 2021 13:51
Implementation of basis pursuit denoising with StructuredOptimization.jl
using StructuredOptimization
"""
Simple implementation of basis pursuit denoising using StructuredOptimization.jl
INPUT
-----
m, n : Size of the image in both direction.
idx : Linear indices of the measured pixels.
y : Pixel measurements.
using LinearAlgebra
using Convex, SCS
# --> Direct resolution of the measurement equation.
lstsq(Θ, y) = Θ \ y
# --> Constrained least-squares formulation.
function cstrnd_lstsq(Θ, y, Σ)
# --> Optimization variable.
a = Convex.Variable(length(Σ))
from scipy.linalg import qr
def sensor_placement(Psi):
# --> Perform QR w/ column pivoting.
_, _, p = qr(Psi.T, pivoting=True, mode="economic")
return p[:Psi.shape[1]]
using LinearAlgebra
function sensor_placement(Ψ)
# --> Compute the QR w/ column pivoting decomposition of Ψ.
_, _, p = qr(transpose(Ψ), Val(true))
return p[1:size(Ψ, 2)]
end
@loiseaujc
loiseaujc / SoftMax_regression.py
Last active February 15, 2021 11:36
Simple implementation of SoftMax regression using gradient descent with quasi-optimal adaptive learning rate.
# --> Import standard Python libraries.
import numpy as np
from scipy.special import softmax
from scipy.linalg import norm
from scipy.optimize import line_search, minimize_scalar
# --> Import sklearn utility functions.
from sklearn.base import BaseEstimator, ClassifierMixin
def SoftMax(x):
# Author : Jean-Christophe Loiseau <[email protected]>
# Date : July 2020
# --> Standard python libraries.
import numpy as np
from scipy.linalg import pinv, eigh, eig
def dmd_analysis(x, y=None, rank=2):
# --> Partition data matrix into X and Y.