Ok. If I understood correctly, the function will test the current solution is violating the cuts that I've had set up before, correct? 

Sorry for asking, but what do you mean by "roll your own"?

Thanks

Ok. If I understood correctly, the function will test the current solution is violating the cuts that I've had set up before, correct? 

Sorry for asking, but what do you mean by "roll your own"?

Thanks

So, if I understood correct, CPLEX check if the current solution is violating the cuts that I've had pre-defined. 

And then using the function self.add()  add them into the model. However, I got this mistake here:

status CPLEX Error 1121: Can't crush solution form.

Any ideas?

Ok. If I understood correctly, the function will test the current solution is violating the cuts that I've had set up before, correct? 

Sorry for asking, but what do you mean by "roll your own"?

Thanks

So, if I understood correct, CPLEX check if the current solution is violating the cuts that I've had pre-defined. 

And then using the function self.add()  add them into the model. However, I got this mistake here:

status CPLEX Error 1121: Can't crush solution form.

Any ideas?

Ok. If I understood correctly, the function will test the current solution is violating the cuts that I've had set up before, correct? 

Sorry for asking, but what do you mean by "roll your own"?

Thanks

So, if I understood correct, CPLEX check if the current solution is violating the cuts that I've had pre-defined. 

And then using the function self.add()  add them into the model. However, I got this mistake here:

status CPLEX Error 1121: Can't crush solution form.

Any ideas?

Ok. If I understood correctly, the function will test the current solution is violating the cuts that I've had set up before, correct? 

Sorry for asking, but what do you mean by "roll your own"?

Thanks

I attached the code here, maybe there's another issue.

If anyone could help, it would be very much appreciated.

So, if I understood correct, CPLEX check if the current solution is violating the cuts that I've had pre-defined. 

And then using the function self.add()  add them into the model. However, I got this mistake here:

status CPLEX Error 1121: Can't crush solution form.

Any ideas?

Ok. If I understood correctly, the function will test the current solution is violating the cuts that I've had set up before, correct? 

Sorry for asking, but what do you mean by "roll your own"?

Thanks

I attached the code here, maybe there's another issue.

If anyone could help, it would be very much appreciated.

So, if I understood correct, CPLEX check if the current solution is violating the cuts that I've had pre-defined. 

And then using the function self.add()  add them into the model. However, I got this mistake here:

status CPLEX Error 1121: Can't crush solution form.

Any ideas?

Ok. If I understood correctly, the function will test the current solution is violating the cuts that I've had set up before, correct? 

Sorry for asking, but what do you mean by "roll your own"?

Thanks

Thank you

I removed most of the things I could. It should be easier to run now.

I attached the code here, maybe there's another issue.

If anyone could help, it would be very much appreciated.

So, if I understood correct, CPLEX check if the current solution is violating the cuts that I've had pre-defined. 

And then using the function self.add()  add them into the model. However, I got this mistake here:

status CPLEX Error 1121: Can't crush solution form.

Any ideas?

Ok. If I understood correctly, the function will test the current solution is violating the cuts that I've had set up before, correct? 

Sorry for asking, but what do you mean by "roll your own"?

Thanks

Thank you

I removed most of the things I could. It should be easier to run now.

I attached the code here, maybe there's another issue.

If anyone could help, it would be very much appreciated.

So, if I understood correct, CPLEX check if the current solution is violating the cuts that I've had pre-defined. 

And then using the function self.add()  add them into the model. However, I got this mistake here:

status CPLEX Error 1121: Can't crush solution form.

Any ideas?

Ok. If I understood correctly, the function will test the current solution is violating the cuts that I've had set up before, correct? 

Sorry for asking, but what do you mean by "roll your own"?

Thanks

Hey

I made some adjustments and now the code at least run but the cuts don't work properly. Probably because they're set up as usercuts, but what I need to do is use them as lazy constraints.

Any idea how to change that?

Thank you

I removed most of the things I could. It should be easier to run now.

I attached the code here, maybe there's another issue.

If anyone could help, it would be very much appreciated.

So, if I understood correct, CPLEX check if the current solution is violating the cuts that I've had pre-defined. 

And then using the function self.add()  add them into the model. However, I got this mistake here:

status CPLEX Error 1121: Can't crush solution form.

Any ideas?

Ok. If I understood correctly, the function will test the current solution is violating the cuts that I've had set up before, correct? 

Sorry for asking, but what do you mean by "roll your own"?

Thanks

Hey

I made some adjustments and now the code at least run but the cuts don't work properly. Probably because they're set up as usercuts, but what I need to do is use them as lazy constraints.

Any idea how to change that?

Thank you

I removed most of the things I could. It should be easier to run now.

I attached the code here, maybe there's another issue.

If anyone could help, it would be very much appreciated.

So, if I understood correct, CPLEX check if the current solution is violating the cuts that I've had pre-defined. 

And then using the function self.add()  add them into the model. However, I got this mistake here:

status CPLEX Error 1121: Can't crush solution form.

Any ideas?

Ok. If I understood correctly, the function will test the current solution is violating the cuts that I've had set up before, correct? 

Sorry for asking, but what do you mean by "roll your own"?

Thanks

Thank you very much for your answer.
One more question:  The current version check for cut violation at every LP solution, I want to change that so it can check violation and eventually add the cuts only after it finds an integer solution. Any suggestions on how to do that?

Thank you again;

Hey

I made some adjustments and now the code at least run but the cuts don't work properly. Probably because they're set up as usercuts, but what I need to do is use them as lazy constraints.

Any idea how to change that?

Thank you

I removed most of the things I could. It should be easier to run now.

I attached the code here, maybe there's another issue.

If anyone could help, it would be very much appreciated.

So, if I understood correct, CPLEX check if the current solution is violating the cuts that I've had pre-defined. 

And then using the function self.add()  add them into the model. However, I got this mistake here:

status CPLEX Error 1121: Can't crush solution form.

Any ideas?

Ok. If I understood correctly, the function will test the current solution is violating the cuts that I've had set up before, correct? 

Sorry for asking, but what do you mean by "roll your own"?

Thanks

I got this current class for callbacks using lazy constraints:

#######################################################################
class MyCutCallback(IncumbentCallback, LazyConstraintCallback):

def __init__(self, env):
LazyConstraintCallback.__init__(self, env)
IncumbentCallback.__init__(self)
self.eps = 1e-6
self.nb_cuts = 0

def add_cut_constraint(self, ct):
self.register_constraint(ct)

def __call__(self):

sol = self.make_solution()

unsats = self.get_cpx_unsatisfied_cts(self.cts, sol, self.eps)

for ct, cut, sense, rhs in unsats:
self.add(cut, sense, rhs)
self.nb_cuts += 1
print('-- add new cut[{0}]: [{1!s}]'.format(self.nb_cuts, ct))
##########################################################################

But I need to make this only add cuts after finding an integer solution. How can I make this happen?

I found some material about incumbent callbacks, but how do I get there?

Thank you very much

Thank you very much for your answer.
One more question:  The current version check for cut violation at every LP solution, I want to change that so it can check violation and eventually add the cuts only after it finds an integer solution. Any suggestions on how to do that?

Thank you again;

Hey

I made some adjustments and now the code at least run but the cuts don't work properly. Probably because they're set up as usercuts, but what I need to do is use them as lazy constraints.

Any idea how to change that?

Thank you

I removed most of the things I could. It should be easier to run now.

I attached the code here, maybe there's another issue.

If anyone could help, it would be very much appreciated.

So, if I understood correct, CPLEX check if the current solution is violating the cuts that I've had pre-defined. 

And then using the function self.add()  add them into the model. However, I got this mistake here:

status CPLEX Error 1121: Can't crush solution form.

Any ideas?

Ok. If I understood correctly, the function will test the current solution is violating the cuts that I've had set up before, correct? 

Sorry for asking, but what do you mean by "roll your own"?

Thanks

I got this current class for callbacks using lazy constraints:

#######################################################################
class MyCutCallback(IncumbentCallback, LazyConstraintCallback):

def __init__(self, env):
LazyConstraintCallback.__init__(self, env)
IncumbentCallback.__init__(self)
self.eps = 1e-6
self.nb_cuts = 0

def add_cut_constraint(self, ct):
self.register_constraint(ct)

def __call__(self):

sol = self.make_solution()

unsats = self.get_cpx_unsatisfied_cts(self.cts, sol, self.eps)

for ct, cut, sense, rhs in unsats:
self.add(cut, sense, rhs)
self.nb_cuts += 1
print('-- add new cut[{0}]: [{1!s}]'.format(self.nb_cuts, ct))
##########################################################################

But I need to make this only add cuts after finding an integer solution. How can I make this happen?

I found some material about incumbent callbacks, but how do I get there?

Thank you very much

Thank you very much for your answer.
One more question:  The current version check for cut violation at every LP solution, I want to change that so it can check violation and eventually add the cuts only after it finds an integer solution. Any suggestions on how to do that?

Thank you again;

Hey

I made some adjustments and now the code at least run but the cuts don't work properly. Probably because they're set up as usercuts, but what I need to do is use them as lazy constraints.

Any idea how to change that?

Thank you

I removed most of the things I could. It should be easier to run now.

I attached the code here, maybe there's another issue.

If anyone could help, it would be very much appreciated.

So, if I understood correct, CPLEX check if the current solution is violating the cuts that I've had pre-defined. 

And then using the function self.add()  add them into the model. However, I got this mistake here:

status CPLEX Error 1121: Can't crush solution form.

Any ideas?

Ok. If I understood correctly, the function will test the current solution is violating the cuts that I've had set up before, correct? 

Sorry for asking, but what do you mean by "roll your own"?

Thanks

If this is the case, I think it will work then

Another issue that I'm facing is that the callbacks are adding many cuts early in the B&C? I don't think this is necessarily correct.

Any ideas?

Thank you very much for your help


#######################################################################
class MyCutCallback(IncumbentCallback, LazyConstraintCallback):

def __init__(self, env):
LazyConstraintCallback.__init__(self, env)
IncumbentCallback.__init__(self)
self.eps = 1e-6
self.nb_cuts = 0

def add_cut_constraint(self, ct):
self.register_constraint(ct)

def __call__(self):

sol = self.make_solution()

unsats = self.get_cpx_unsatisfied_cts(self.cts, sol, self.eps)

for ct, cut, sense, rhs in unsats:
self.add(cut, sense, rhs)
self.nb_cuts += 1
print('-- add new cut[{0}]: [{1!s}]'.format(self.nb_cuts, ct))
##########################################################################

I got this current class for callbacks using lazy constraints:

#######################################################################
class MyCutCallback(IncumbentCallback, LazyConstraintCallback):

def __init__(self, env):
LazyConstraintCallback.__init__(self, env)
IncumbentCallback.__init__(self)
self.eps = 1e-6
self.nb_cuts = 0

def add_cut_constraint(self, ct):
self.register_constraint(ct)

def __call__(self):

sol = self.make_solution()

unsats = self.get_cpx_unsatisfied_cts(self.cts, sol, self.eps)

for ct, cut, sense, rhs in unsats:
self.add(cut, sense, rhs)
self.nb_cuts += 1
print('-- add new cut[{0}]: [{1!s}]'.format(self.nb_cuts, ct))
##########################################################################

But I need to make this only add cuts after finding an integer solution. How can I make this happen?

I found some material about incumbent callbacks, but how do I get there?

Thank you very much

Thank you very much for your answer.
One more question:  The current version check for cut violation at every LP solution, I want to change that so it can check violation and eventually add the cuts only after it finds an integer solution. Any suggestions on how to do that?

Thank you again;

Hey

I made some adjustments and now the code at least run but the cuts don't work properly. Probably because they're set up as usercuts, but what I need to do is use them as lazy constraints.

Any idea how to change that?

Thank you

I removed most of the things I could. It should be easier to run now.

I attached the code here, maybe there's another issue.

If anyone could help, it would be very much appreciated.

So, if I understood correct, CPLEX check if the current solution is violating the cuts that I've had pre-defined. 

And then using the function self.add()  add them into the model. However, I got this mistake here:

status CPLEX Error 1121: Can't crush solution form.

Any ideas?

Ok. If I understood correctly, the function will test the current solution is violating the cuts that I've had set up before, correct? 

Sorry for asking, but what do you mean by "roll your own"?

Thanks