I am trying to minimize a piecewise function using cvxpy












1














I want to minimize a



piecewise f(x) : 
as-bx, x=>s+c
-bx, x<=c
a(x-c)-bx, c<=x<=c+s


I used Lagrangian multiplier and reformulate the problem:



f(x)=(as-bx1)y1 +(-bx2)y2+(a(x3-c)-bx3)y3

s.t: x=>(s+c)y1
x<=cy2
cy3<=x<=(c+s)y3
x1+x2+x3 =G


I used cvxpy and ECOS_BB solver but I get "PRIMAL INFEASIBLE (within feastol=8.8e-09)."



could anyone please help me to print the solver first iteration solutions and any comment on how can I overcome the infeasibility situation.










share|improve this question
























  • What coefficients are you using? a, b, c, s?
    – Jacques Kvam
    Nov 23 '18 at 20:51
















1














I want to minimize a



piecewise f(x) : 
as-bx, x=>s+c
-bx, x<=c
a(x-c)-bx, c<=x<=c+s


I used Lagrangian multiplier and reformulate the problem:



f(x)=(as-bx1)y1 +(-bx2)y2+(a(x3-c)-bx3)y3

s.t: x=>(s+c)y1
x<=cy2
cy3<=x<=(c+s)y3
x1+x2+x3 =G


I used cvxpy and ECOS_BB solver but I get "PRIMAL INFEASIBLE (within feastol=8.8e-09)."



could anyone please help me to print the solver first iteration solutions and any comment on how can I overcome the infeasibility situation.










share|improve this question
























  • What coefficients are you using? a, b, c, s?
    – Jacques Kvam
    Nov 23 '18 at 20:51














1












1








1


1





I want to minimize a



piecewise f(x) : 
as-bx, x=>s+c
-bx, x<=c
a(x-c)-bx, c<=x<=c+s


I used Lagrangian multiplier and reformulate the problem:



f(x)=(as-bx1)y1 +(-bx2)y2+(a(x3-c)-bx3)y3

s.t: x=>(s+c)y1
x<=cy2
cy3<=x<=(c+s)y3
x1+x2+x3 =G


I used cvxpy and ECOS_BB solver but I get "PRIMAL INFEASIBLE (within feastol=8.8e-09)."



could anyone please help me to print the solver first iteration solutions and any comment on how can I overcome the infeasibility situation.










share|improve this question















I want to minimize a



piecewise f(x) : 
as-bx, x=>s+c
-bx, x<=c
a(x-c)-bx, c<=x<=c+s


I used Lagrangian multiplier and reformulate the problem:



f(x)=(as-bx1)y1 +(-bx2)y2+(a(x3-c)-bx3)y3

s.t: x=>(s+c)y1
x<=cy2
cy3<=x<=(c+s)y3
x1+x2+x3 =G


I used cvxpy and ECOS_BB solver but I get "PRIMAL INFEASIBLE (within feastol=8.8e-09)."



could anyone please help me to print the solver first iteration solutions and any comment on how can I overcome the infeasibility situation.







cvxpy mixed-integer-programming






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 23 '18 at 13:37









Vinay Pandey

4,51162947




4,51162947










asked Nov 23 '18 at 4:25









Helena

61




61












  • What coefficients are you using? a, b, c, s?
    – Jacques Kvam
    Nov 23 '18 at 20:51


















  • What coefficients are you using? a, b, c, s?
    – Jacques Kvam
    Nov 23 '18 at 20:51
















What coefficients are you using? a, b, c, s?
– Jacques Kvam
Nov 23 '18 at 20:51




What coefficients are you using? a, b, c, s?
– Jacques Kvam
Nov 23 '18 at 20:51












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