lsqlin
Solves a linear quadratic problem.
Calling Sequence
xopt = lsqlin(C,d,A,b)
xopt = lsqlin(C,d,A,b,Aeq,beq)
xopt = lsqlin(C,d,A,b,Aeq,beq,lb,ub)
xopt = lsqlin(C,d,A,b,Aeq,beq,lb,ub,x0)
xopt = lsqlin(C,d,A,b,Aeq,beq,lb,ub,x0,param)
[xopt,resnorm,residual,exitflag,output,lambda] = lsqlin( ... )
Parameters
C :
a matrix of double, represents the multiplier of the solution x in the expression C*x - d. Number of columns in C is equal to the number of elements in x.
d :
a vector of double, represents the additive constant term in the expression C*x - d. Number of elements in d is equal to the number of rows in C matrix.
A :
a vector of double, represents the linear coefficients in the inequality constraints
b :
a vector of double, represents the linear coefficients in the inequality constraints
Aeq :
a matrix of double, represents the linear coefficients in the equality constraints
beq :
a vector of double, represents the linear coefficients in the equality constraints
lb :
a vector of double, contains lower bounds of the variables.
ub :
a vector of double, contains upper bounds of the variables.
x0 :
a vector of double, contains initial guess of variables.
param :
a list containing the the parameters to be set.
xopt :
a vector of double, the computed solution of the optimization problem.
resnorm :
a double, objective value returned as the scalar value norm(C*x-d)^2.
residual :
a vector of double, solution residuals returned as the vector d-C*x.
exitflag :
A flag showing returned exit flag from Ipopt. It could be 0, 1 or 2 etc. i.e. Optimal, Maximum Number of Iterations Exceeded, CPU time exceeded. Other flags one can see in the lsqlin macro.
output :
Structure containing information about the optimization. This version only contains number of iterations.
lambda :
Structure containing the Lagrange multipliers at the solution x (separated by constraint type).It contains lower, upper bound multiplier and linear equality, inequality constraint multiplier.
Description
Search the minimum of a constrained linear least square problem specified by :
\begin{eqnarray}
&\mbox{min}_{x}
& 1/2||C⋅x - d||_2^2 \\
& \text{subject to} & A⋅x \leq b \\
& & Aeq⋅x = beq \\
& & lb \leq x \leq ub \\
\end{eqnarray}
The routine calls Ipopt for solving the linear least square problem, Ipopt is a library written in C++.
Examples
Examples
Authors
Harpreet Singh