Projection on convex sets with equality and inequality constraints












0












$begingroup$


I want to find the projection of a vector called "a" on a closed and convex set with linear constraints. The set is in the following form:
begin{array}{ll}
& Ax = b \
& Bx le d \
&x ge 0.
end{array}

I know I need to solve the following problem to get the projection:
begin{array}{ll}
text{minimize} & || x-a||^2 \
& Ax = b \
& Bx le d \
&x ge 0.
end{array}

However, I am looking for an efficient way (instead of solving with commercial software like CPLEX) using the structure, convexity, and linearity of the set. I was wondering if anyone knows how to find the projection on this type of feasible region and space properties efficiently. Any resource that has addressed this issue will also help a lot.
Note that I found this "Projection of $z$ onto the affine set ${xmid Ax = b}$" here, but the KKT condition requires other conditions in my problem that lead to non-linear constraints.
Thanks in advance for your help.










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$endgroup$












  • $begingroup$
    You could use any quadratic program (QP) solver. For example, SQOPT.
    $endgroup$
    – copper.hat
    Dec 8 '18 at 2:28












  • $begingroup$
    Thanks for your reply. CPLEX can solve quadratic objectives with the set of constraints, and I get the optimal solutions, but I am looking for efficient ways to solve this problem using mathematical properties like getting the solution by multiplying some matrices and doing similar things instead of optimizing using commercial software.
    $endgroup$
    – Mehrzad
    Dec 8 '18 at 23:22
















0












$begingroup$


I want to find the projection of a vector called "a" on a closed and convex set with linear constraints. The set is in the following form:
begin{array}{ll}
& Ax = b \
& Bx le d \
&x ge 0.
end{array}

I know I need to solve the following problem to get the projection:
begin{array}{ll}
text{minimize} & || x-a||^2 \
& Ax = b \
& Bx le d \
&x ge 0.
end{array}

However, I am looking for an efficient way (instead of solving with commercial software like CPLEX) using the structure, convexity, and linearity of the set. I was wondering if anyone knows how to find the projection on this type of feasible region and space properties efficiently. Any resource that has addressed this issue will also help a lot.
Note that I found this "Projection of $z$ onto the affine set ${xmid Ax = b}$" here, but the KKT condition requires other conditions in my problem that lead to non-linear constraints.
Thanks in advance for your help.










share|cite|improve this question











$endgroup$












  • $begingroup$
    You could use any quadratic program (QP) solver. For example, SQOPT.
    $endgroup$
    – copper.hat
    Dec 8 '18 at 2:28












  • $begingroup$
    Thanks for your reply. CPLEX can solve quadratic objectives with the set of constraints, and I get the optimal solutions, but I am looking for efficient ways to solve this problem using mathematical properties like getting the solution by multiplying some matrices and doing similar things instead of optimizing using commercial software.
    $endgroup$
    – Mehrzad
    Dec 8 '18 at 23:22














0












0








0





$begingroup$


I want to find the projection of a vector called "a" on a closed and convex set with linear constraints. The set is in the following form:
begin{array}{ll}
& Ax = b \
& Bx le d \
&x ge 0.
end{array}

I know I need to solve the following problem to get the projection:
begin{array}{ll}
text{minimize} & || x-a||^2 \
& Ax = b \
& Bx le d \
&x ge 0.
end{array}

However, I am looking for an efficient way (instead of solving with commercial software like CPLEX) using the structure, convexity, and linearity of the set. I was wondering if anyone knows how to find the projection on this type of feasible region and space properties efficiently. Any resource that has addressed this issue will also help a lot.
Note that I found this "Projection of $z$ onto the affine set ${xmid Ax = b}$" here, but the KKT condition requires other conditions in my problem that lead to non-linear constraints.
Thanks in advance for your help.










share|cite|improve this question











$endgroup$




I want to find the projection of a vector called "a" on a closed and convex set with linear constraints. The set is in the following form:
begin{array}{ll}
& Ax = b \
& Bx le d \
&x ge 0.
end{array}

I know I need to solve the following problem to get the projection:
begin{array}{ll}
text{minimize} & || x-a||^2 \
& Ax = b \
& Bx le d \
&x ge 0.
end{array}

However, I am looking for an efficient way (instead of solving with commercial software like CPLEX) using the structure, convexity, and linearity of the set. I was wondering if anyone knows how to find the projection on this type of feasible region and space properties efficiently. Any resource that has addressed this issue will also help a lot.
Note that I found this "Projection of $z$ onto the affine set ${xmid Ax = b}$" here, but the KKT condition requires other conditions in my problem that lead to non-linear constraints.
Thanks in advance for your help.







convex-analysis projection






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share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 11 '18 at 1:39







Mehrzad

















asked Dec 8 '18 at 2:01









Mehrzad Mehrzad

63




63












  • $begingroup$
    You could use any quadratic program (QP) solver. For example, SQOPT.
    $endgroup$
    – copper.hat
    Dec 8 '18 at 2:28












  • $begingroup$
    Thanks for your reply. CPLEX can solve quadratic objectives with the set of constraints, and I get the optimal solutions, but I am looking for efficient ways to solve this problem using mathematical properties like getting the solution by multiplying some matrices and doing similar things instead of optimizing using commercial software.
    $endgroup$
    – Mehrzad
    Dec 8 '18 at 23:22


















  • $begingroup$
    You could use any quadratic program (QP) solver. For example, SQOPT.
    $endgroup$
    – copper.hat
    Dec 8 '18 at 2:28












  • $begingroup$
    Thanks for your reply. CPLEX can solve quadratic objectives with the set of constraints, and I get the optimal solutions, but I am looking for efficient ways to solve this problem using mathematical properties like getting the solution by multiplying some matrices and doing similar things instead of optimizing using commercial software.
    $endgroup$
    – Mehrzad
    Dec 8 '18 at 23:22
















$begingroup$
You could use any quadratic program (QP) solver. For example, SQOPT.
$endgroup$
– copper.hat
Dec 8 '18 at 2:28






$begingroup$
You could use any quadratic program (QP) solver. For example, SQOPT.
$endgroup$
– copper.hat
Dec 8 '18 at 2:28














$begingroup$
Thanks for your reply. CPLEX can solve quadratic objectives with the set of constraints, and I get the optimal solutions, but I am looking for efficient ways to solve this problem using mathematical properties like getting the solution by multiplying some matrices and doing similar things instead of optimizing using commercial software.
$endgroup$
– Mehrzad
Dec 8 '18 at 23:22




$begingroup$
Thanks for your reply. CPLEX can solve quadratic objectives with the set of constraints, and I get the optimal solutions, but I am looking for efficient ways to solve this problem using mathematical properties like getting the solution by multiplying some matrices and doing similar things instead of optimizing using commercial software.
$endgroup$
– Mehrzad
Dec 8 '18 at 23:22










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