# Objective: convex quadratic # Constraints: linear param m; param n; param b {1..m}; param A {1..m, 1..n}; var x {1..n} >= 0; var t {1..m}; minimize sum_sqs: sum {i in 1..m} t[i]^2; subject to defs {i in 1..m}: t[i] = b[i] - sum {j in 1..n} A[i,j]*x[j]; data; param m := 500; param n := 150; #param m := 1000; #param n := 300; #param m := 512; #param n := 1024; let {i in 1..m, j in 1..n} A[i,j] := 0; let {i in 1..m, j in 1..n: Uniform01() < 0.01} A[i,j] := Uniform01(); param x0 {j in 1..n} := Uniform01(); let {i in 1..m} b[i] := sum {j in 1..n} A[i,j]*x0[j] + Uniform01()-0.5; #option loqo_options "timing=1 verbose=2"; #option minos_options "timing=1 superbasics=1000"; #option lancelot_options "timing=1"; #option solver loqo; # 1m40.85s #option solver minos; # fails #option solver lancelot; # 1m12.86s solve;