write_an_optimizer_state.py

## \example kernel/write_an_optimizer_state.py
# While we do not recomment doing serious work using optimizer states
# written it python, it is often useful when prototyping or testing code.
# Copy this example and modify as needed.

import IMP

# an optimizer state which prints out the last scores of some restraints.


class MyOptimizerState(IMP.OptimizerState):

    def __init__(self, rs):
        IMP.OptimizerState.__init__(self, rs[0].get_model(),
                                    "MyOptimizerState%1%")
        self.rs = rs

    def update(self):
        for r in self.rs:
            print r.get_name(), r.get_last_score()

# some code to create and evaluate it
k = IMP.FloatKey("a key")
m = IMP.kernel.Model()
# we don't have any real restraints in the kernel
r0 = IMP.kernel._ConstRestraint(m, [], 1)
r0.set_name("restraint 0")

r1 = IMP.kernel._ConstRestraint(m, [], 2)
r1.set_name("restraint 1")

rs = IMP.kernel.RestraintSet([r0, r1], 1.0)
sf = rs.create_scoring_function()

os = MyOptimizerState([r0, r1])
os.set_name("python optimizer state")
# we don't have any optimizers either
co = IMP.kernel._ConstOptimizer(m)
co.set_scoring_function(sf)
co.add_optimizer_state(os)
print co.optimize(100)

# this is needed to clean up memory properly for some reason
co.remove_optimizer_state(os)
del os
del m