Assessor receive intermediate result from Trial and decide whether the Trial should be killed. Once the Trial experiment meets the early stop conditions, the assessor will kill the Trial.
So, if user want to implement a customized Assessor, she/he only need to:
1) Inherit a tuner of a base Tuner class
from nni.assessor import Assessor
class CustomizedAssessor(Assessor):
def __init__(self, ...):
...
2) Implement assess trial function
from nni.assessor import Assessor, AssessResult
class CustomizedAssessor(Assessor):
def __init__(self, ...):
...
def assess_trial(self, trial_history):
"""
Determines whether a trial should be killed. Must override.
trial_history: a list of intermediate result objects.
Returns AssessResult.Good or AssessResult.Bad.
"""
# you code implement here.
...
3) Write a script to run Tuner
import argparse
import CustomizedAssesor
def main():
parser = argparse.ArgumentParser(description='parse command line parameters.')
# parse your assessor arg here.
...
FLAGS, unparsed = parser.parse_known_args()
tuner = CustomizedAssessor(...)
tuner.run()
main()
Please noted in 2). The object trial_history
are exact the object that Trial send to Assesor by using SDK report_intermediate_result
function.
Also, user could override the run
function in Assessor to control the process logic.
More detail example you could see: