Does pyomo provide access to cplex callbacks?
I'm relatively new in Pyomo and I have some problems getting access to the cplex callback for generating user cuts.
I'm using Pyomo 5.5.0 and cplex 12.8.0.0, I've already defined an Abstract model and loaded the data, now I would like to specify the cplex UserCutCallback in order to add user-written cuts during the branch-and-cut search performed by cplex.
I tried the following:
# model definition
model = AbstractModel()
...
# load the instance
instance = model.create_instance(data = 'data.dat')
# the callback that cplex should call during the branch-and-cut search
def cut_callback(solver, model):
print("CB-Cut")
opt = SolverFactory('cplex_direct')
opt.set_callback('cut-callback', cut_callback)
But I got the following error:
~/miniconda3/envs/opt/lib/python3.6/site-packages/pyomo/opt/bas/solvers.py in set_callback(self, name, callback_fn)
815 if not self._allow_callbacks:
816 raise pyutilib.common.ApplicationError(
--> 817 "Callbacks disabled for solver %s" % self.name)
818 if callback_fn is None:
819 if name in self._callback:
ApplicationError: Callbacks disabled for solver cplexdirect
The interface cplex direct works correctly when I do not specify any callbacks, but when I call the method set_callback I got the above error, and so I started wondering if there is a way to get access to the cplex callbacks from pyomo. I really need that!
Is this feature available in pyomo? Am I missing something?
Thanks for your help
cplex pyomo
asked Nov 12 '18 at 22:30
Riccardo
61
add a comment |
I'm relatively new in Pyomo and I have some problems getting access to the cplex callback for generating user cuts.
I'm using Pyomo 5.5.0 and cplex 12.8.0.0, I've already defined an Abstract model and loaded the data, now I would like to specify the cplex UserCutCallback in order to add user-written cuts during the branch-and-cut search performed by cplex.
I tried the following:
# model definition
model = AbstractModel()
...
# load the instance
instance = model.create_instance(data = 'data.dat')
# the callback that cplex should call during the branch-and-cut search
def cut_callback(solver, model):
print("CB-Cut")
opt = SolverFactory('cplex_direct')
opt.set_callback('cut-callback', cut_callback)
But I got the following error:
~/miniconda3/envs/opt/lib/python3.6/site-packages/pyomo/opt/bas/solvers.py in set_callback(self, name, callback_fn)
815 if not self._allow_callbacks:
816 raise pyutilib.common.ApplicationError(
--> 817 "Callbacks disabled for solver %s" % self.name)
818 if callback_fn is None:
819 if name in self._callback:
ApplicationError: Callbacks disabled for solver cplexdirect
The interface cplex direct works correctly when I do not specify any callbacks, but when I call the method set_callback I got the above error, and so I started wondering if there is a way to get access to the cplex callbacks from pyomo. I really need that!
Is this feature available in pyomo? Am I missing something?
Thanks for your help
cplex pyomo
asked Nov 12 '18 at 22:30
Riccardo
61
I'm not a pyomo expert, but the error seems to be pretty clear. Thecplex_directsolver has an attribute (_allow_callbacks) which isFalseand when you try to set the callback it tells you that callbacks are not supported. Is there some reason why you don't trust the error? This seems like a question that should really go directly to the developers of pyomo (they must have a forum somewhere). In order to use CPLEX callbacks you may need to consider using eitherdocplex(a Python modeling language provided by IBM) or the CPLEX Python API directly (i.e., thecplexpackage).
– rkersh
Nov 14 '18 at 16:50
rkersh, you are right the error is very clear, but the problem is that I wasn't expecting the value False for the attribute _allow_callbacks. I even notice that in the source code there is no method that set _allow_callback to True, and it seems to me that this feature is not implemented. Or maybe I just forgot something that enable the cplex callbacks. The cplex API are a valid alternative but I would like to use pyomo, since I already have my models written with Pyomo. Anyway, If I won't find a way to solve this problem I will consider docplex or the cplex python API. - Thanks, Riccardo
– Riccardo
Nov 16 '18 at 9:13
add a comment |
I'm relatively new in Pyomo and I have some problems getting access to the cplex callback for generating user cuts.
I'm using Pyomo 5.5.0 and cplex 12.8.0.0, I've already defined an Abstract model and loaded the data, now I would like to specify the cplex UserCutCallback in order to add user-written cuts during the branch-and-cut search performed by cplex.
I tried the following:
# model definition
model = AbstractModel()
...
# load the instance
instance = model.create_instance(data = 'data.dat')
# the callback that cplex should call during the branch-and-cut search
def cut_callback(solver, model):
print("CB-Cut")
opt = SolverFactory('cplex_direct')
opt.set_callback('cut-callback', cut_callback)
But I got the following error:
~/miniconda3/envs/opt/lib/python3.6/site-packages/pyomo/opt/bas/solvers.py in set_callback(self, name, callback_fn)
815 if not self._allow_callbacks:
816 raise pyutilib.common.ApplicationError(
--> 817 "Callbacks disabled for solver %s" % self.name)
818 if callback_fn is None:
819 if name in self._callback:
ApplicationError: Callbacks disabled for solver cplexdirect
The interface cplex direct works correctly when I do not specify any callbacks, but when I call the method set_callback I got the above error, and so I started wondering if there is a way to get access to the cplex callbacks from pyomo. I really need that!
Is this feature available in pyomo? Am I missing something?
Thanks for your help
cplex pyomo
asked Nov 12 '18 at 22:30
Riccardo
61
I'm relatively new in Pyomo and I have some problems getting access to the cplex callback for generating user cuts.
I'm using Pyomo 5.5.0 and cplex 12.8.0.0, I've already defined an Abstract model and loaded the data, now I would like to specify the cplex UserCutCallback in order to add user-written cuts during the branch-and-cut search performed by cplex.
I tried the following:
# model definition
model = AbstractModel()
...
# load the instance
instance = model.create_instance(data = 'data.dat')
# the callback that cplex should call during the branch-and-cut search
def cut_callback(solver, model):
print("CB-Cut")
opt = SolverFactory('cplex_direct')
opt.set_callback('cut-callback', cut_callback)
But I got the following error:
~/miniconda3/envs/opt/lib/python3.6/site-packages/pyomo/opt/bas/solvers.py in set_callback(self, name, callback_fn)
815 if not self._allow_callbacks:
816 raise pyutilib.common.ApplicationError(
--> 817 "Callbacks disabled for solver %s" % self.name)
818 if callback_fn is None:
819 if name in self._callback:
ApplicationError: Callbacks disabled for solver cplexdirect
The interface cplex direct works correctly when I do not specify any callbacks, but when I call the method set_callback I got the above error, and so I started wondering if there is a way to get access to the cplex callbacks from pyomo. I really need that!
Is this feature available in pyomo? Am I missing something?
Thanks for your help
cplex pyomo
cplex pyomo
asked Nov 12 '18 at 22:30
Riccardo
61
asked Nov 12 '18 at 22:30
Riccardo
61
asked Nov 12 '18 at 22:30
Riccardo
61
asked Nov 12 '18 at 22:30
Riccardo
61
asked Nov 12 '18 at 22:30
Riccardo
61
61
I'm not a pyomo expert, but the error seems to be pretty clear. Thecplex_directsolver has an attribute (_allow_callbacks) which isFalseand when you try to set the callback it tells you that callbacks are not supported. Is there some reason why you don't trust the error? This seems like a question that should really go directly to the developers of pyomo (they must have a forum somewhere). In order to use CPLEX callbacks you may need to consider using eitherdocplex(a Python modeling language provided by IBM) or the CPLEX Python API directly (i.e., thecplexpackage).
– rkersh
Nov 14 '18 at 16:50
rkersh, you are right the error is very clear, but the problem is that I wasn't expecting the value False for the attribute _allow_callbacks. I even notice that in the source code there is no method that set _allow_callback to True, and it seems to me that this feature is not implemented. Or maybe I just forgot something that enable the cplex callbacks. The cplex API are a valid alternative but I would like to use pyomo, since I already have my models written with Pyomo. Anyway, If I won't find a way to solve this problem I will consider docplex or the cplex python API. - Thanks, Riccardo
– Riccardo
Nov 16 '18 at 9:13
add a comment |
I'm not a pyomo expert, but the error seems to be pretty clear. Thecplex_directsolver has an attribute (_allow_callbacks) which isFalseand when you try to set the callback it tells you that callbacks are not supported. Is there some reason why you don't trust the error? This seems like a question that should really go directly to the developers of pyomo (they must have a forum somewhere). In order to use CPLEX callbacks you may need to consider using eitherdocplex(a Python modeling language provided by IBM) or the CPLEX Python API directly (i.e., thecplexpackage).
– rkersh
Nov 14 '18 at 16:50
rkersh, you are right the error is very clear, but the problem is that I wasn't expecting the value False for the attribute _allow_callbacks. I even notice that in the source code there is no method that set _allow_callback to True, and it seems to me that this feature is not implemented. Or maybe I just forgot something that enable the cplex callbacks. The cplex API are a valid alternative but I would like to use pyomo, since I already have my models written with Pyomo. Anyway, If I won't find a way to solve this problem I will consider docplex or the cplex python API. - Thanks, Riccardo
– Riccardo
Nov 16 '18 at 9:13
I'm not a pyomo expert, but the error seems to be pretty clear. The
cplex_direct solver has an attribute (_allow_callbacks) which is False and when you try to set the callback it tells you that callbacks are not supported. Is there some reason why you don't trust the error? This seems like a question that should really go directly to the developers of pyomo (they must have a forum somewhere). In order to use CPLEX callbacks you may need to consider using either docplex (a Python modeling language provided by IBM) or the CPLEX Python API directly (i.e., the cplex package).– rkersh
Nov 14 '18 at 16:50
I'm not a pyomo expert, but the error seems to be pretty clear. The
cplex_direct solver has an attribute (_allow_callbacks) which is False and when you try to set the callback it tells you that callbacks are not supported. Is there some reason why you don't trust the error? This seems like a question that should really go directly to the developers of pyomo (they must have a forum somewhere). In order to use CPLEX callbacks you may need to consider using either docplex (a Python modeling language provided by IBM) or the CPLEX Python API directly (i.e., the cplex package).– rkersh
Nov 14 '18 at 16:50
rkersh, you are right the error is very clear, but the problem is that I wasn't expecting the value False for the attribute _allow_callbacks. I even notice that in the source code there is no method that set _allow_callback to True, and it seems to me that this feature is not implemented. Or maybe I just forgot something that enable the cplex callbacks. The cplex API are a valid alternative but I would like to use pyomo, since I already have my models written with Pyomo. Anyway, If I won't find a way to solve this problem I will consider docplex or the cplex python API. - Thanks, Riccardo
– Riccardo
Nov 16 '18 at 9:13
rkersh, you are right the error is very clear, but the problem is that I wasn't expecting the value False for the attribute _allow_callbacks. I even notice that in the source code there is no method that set _allow_callback to True, and it seems to me that this feature is not implemented. Or maybe I just forgot something that enable the cplex callbacks. The cplex API are a valid alternative but I would like to use pyomo, since I already have my models written with Pyomo. Anyway, If I won't find a way to solve this problem I will consider docplex or the cplex python API. - Thanks, Riccardo
– Riccardo
Nov 16 '18 at 9:13
add a comment |
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I'm not a pyomo expert, but the error seems to be pretty clear. The
cplex_directsolver has an attribute (_allow_callbacks) which isFalseand when you try to set the callback it tells you that callbacks are not supported. Is there some reason why you don't trust the error? This seems like a question that should really go directly to the developers of pyomo (they must have a forum somewhere). In order to use CPLEX callbacks you may need to consider using eitherdocplex(a Python modeling language provided by IBM) or the CPLEX Python API directly (i.e., thecplexpackage).– rkersh
Nov 14 '18 at 16:50
rkersh, you are right the error is very clear, but the problem is that I wasn't expecting the value False for the attribute _allow_callbacks. I even notice that in the source code there is no method that set _allow_callback to True, and it seems to me that this feature is not implemented. Or maybe I just forgot something that enable the cplex callbacks. The cplex API are a valid alternative but I would like to use pyomo, since I already have my models written with Pyomo. Anyway, If I won't find a way to solve this problem I will consider docplex or the cplex python API. - Thanks, Riccardo
– Riccardo
Nov 16 '18 at 9:13