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luinardi
Problem using Gaussian Process when the objective function value is constant
Hi,
I've tried to run your "branin" example and considering a constant objective value, like "y_value = 1" for each input parameter. I set up the "model" to "Gaussian Process". "models": { "model": "gaussian_process" },
But, it does not work and I've got the following error. Would you please let me know what is the problem?
Best Regards, Zahra
Traceback (most recent call last):
File "branin.py", line 39, in
@rzahra Can you copy-paste the py and json file of the Branin function that you are using here? As I was running myself with y_value=1 and GP, I did not get the error. In general, using a GP for a constant function is not smart but it should work...
#!/usr/bin/python import math
import os import sys import warnings from collections import OrderedDict
from hypermapper import optimizer # noqa
def branin_function(X): """ Compute the branin function. :param X: dictionary containing the input points. :return: the value of the branin function """ x1 = X["x1"] x2 = X["x2"] a = 1.0 b = 5.1 / (4.0 * math.pi * math.pi) c = 5.0 / math.pi r = 6.0 s = 10.0 t = 1.0 / (8.0 * math.pi)
#y_value = a * (x2 - b * x1 * x1 + c * x1 - r) ** 2 + s * (1 - t) * math.cos(x1) + s
y_value = 1
return y_value
def main(): parameters_file = "/home/zahra/Desktop/hypermapper-simple-test/example_scenarios/quick_start/branin_scenario.json" optimizer.optimize(parameters_file, branin_function) print("End of Branin.")
if name == "main": main()
{ "application_name": "branin", "optimization_objectives": ["Value"], "optimization_iterations": 20, "optimization_method": "bayesian_optimization", "acquisition_function_optimizer": "local_search", "design_of_experiment": { "doe_type": "random sampling", "number_of_samples": 3
},
"models": {
"model": "gaussian_process"
},
"input_parameters" : {
"x1": {
"parameter_type" : "real",
"values" : [-5, 10],
"parameter_default" : 0
},
"x2": {
"parameter_type" : "real",
"values" : [0, 15],
"parameter_default" : 0
}
}
}
@rzahra Strange. I didn't get the error. I was using the latest version of Hypermapper from this repo. Pip version is not yet updated as I can see... Can you maybe check that you are using the latest version of Hypermapper or check is there any mismatch between anaconda3 and Hypermapper
My result...
| x1 | x2 | Value | Timestamp |
|---|---|---|---|
| 0 | 0 | 1 | 1 |
| 5.60301701755873 | 6.04807923864642 | 1 | 1 |
| -3.24438823881358 | 12.702020869894 | 1 | 1 |
| 2.19105319236382 | 2.32721787344419 | 1 | 368 |
| 1.18058256785225 | 0.280883034597277 | 1 | 816 |
| 3.77255434050274 | 1.29103718689401 | 1 | 1267 |
| 7.45611027312549 | 0.329748493671475 | 1 | 1706 |
| 10 | 0.396969533465726 | 1 | 2113 |
| 1.51087515746304 | 1.89817942409036 | 1 | 2500 |
| 8.33121229115913 | 1.29476803461852 | 1 | 2949 |
| 5.098804488615 | 1.87438181073141 | 1 | 3388 |
| 3.51543678199592 | 1.7371702889608 | 1 | 3824 |
| 3.12219508823726 | 1.00400351211924 | 1 | 4260 |
| 3.88174205850473 | 1.53863041723447 | 1 | 4736 |
| 8.54319783549642 | 0.8461187299401 | 1 | 5171 |
| 7.85486273117496 | 1.34970757932602 | 1 | 5637 |
| 8.57199759865176 | 0.755149316832652 | 1 | 6061 |
| -1.64473966669573 | 0.213732575999534 | 1 | 6544 |
| 8.3284077498699 | 3.34379278975797 | 1 | 6618 |
| 8.26472155895912 | 0.574587731483283 | 1 | 7075 |
| 6.74071982162813 | 2.10840547806442 | 1 | 7528 |
| 6.5380851578267 | 0.668962647053504 | 1 | 8053 |
| -2.16236399703512 | 0.712652098237651 | 1 | 8510 |