ezmodel - A common interface for models and model selection

Installation

The framework is available at the PyPi Repository:

pip install -U ezmodel

Surrogate Models

Benchmark

import numpy as np

import pandas as pd
pd.set_option('display.expand_frame_repr', False)
pd.set_option('max_colwidth', 1000)

from ezmodel.core.benchmark import Benchmark
from ezmodel.core.factory import models_from_clazzes
from ezmodel.models.kriging import Kriging
from ezmodel.models.rbf import RBF
from ezmodel.util.partitioning.crossvalidation import CrossvalidationPartitioning

X = np.random.random((100, 3)) * 2 * np.pi
y = np.sin(X).sum(axis=1)

models = models_from_clazzes(RBF, Kriging)

# set up the benchmark and add the models to be used
benchmark = Benchmark(models, n_threads=4, verbose=True, raise_exception=True)

# create partitions to validate the performance of each model
partitions = CrossvalidationPartitioning(k_folds=5, seed=1).do(X)

# runs the experiment with the specified partitioning
benchmark.do(X, y, partitions=partitions)

# print out the benchmark results
print(benchmark.statistics("mae"))

                                                             mean       std       min        max    median
label
Kriging[regr=constant,corr=gauss,thetaU=100,ARD=False]       0.017159  0.007472  0.009658   0.025359  0.014855
Kriging[regr=constant,corr=gauss,thetaU=20,ARD=False]        0.017159  0.007472  0.009658   0.025359  0.014855
Kriging[regr=linear,corr=gauss,thetaU=100,ARD=False]         0.018064  0.008069  0.010350   0.027456  0.014246
Kriging[regr=linear,corr=gauss,thetaU=20,ARD=False]          0.018064  0.008069  0.010350   0.027456  0.014246
Kriging[regr=constant,corr=gauss,thetaU=100,ARD=True]        0.021755  0.007409  0.011955   0.028896  0.025163
Kriging[regr=constant,corr=gauss,thetaU=20,ARD=True]         0.021755  0.007409  0.011955   0.028896  0.025163
Kriging[regr=linear,corr=gauss,thetaU=20,ARD=True]           0.025018  0.011348  0.011576   0.040585  0.022124
Kriging[regr=linear,corr=gauss,thetaU=100,ARD=True]          0.025018  0.011348  0.011576   0.040585  0.022124
Kriging[regr=constant,corr=exp,thetaU=100,ARD=False]         0.034493  0.009328  0.025092   0.045610  0.030661
Kriging[regr=constant,corr=exp,thetaU=20,ARD=False]          0.034493  0.009328  0.025092   0.045610  0.030661
Kriging[regr=linear,corr=exp,thetaU=100,ARD=False]           0.035734  0.009922  0.025611   0.047926  0.031473
Kriging[regr=linear,corr=exp,thetaU=20,ARD=False]            0.035734  0.009922  0.025611   0.047926  0.031473
Kriging[regr=constant,corr=exp,thetaU=100,ARD=True]          0.051527  0.010941  0.037944   0.065866  0.047440
Kriging[regr=constant,corr=exp,thetaU=20,ARD=True]           0.051527  0.010941  0.037944   0.065866  0.047440
Kriging[regr=linear,corr=exp,thetaU=100,ARD=True]            0.065867  0.025312  0.039058   0.104449  0.059957
Kriging[regr=linear,corr=exp,thetaU=20,ARD=True]             0.065867  0.025312  0.039058   0.104449  0.059957
RBF[kernel=cubic,tail=quadratic,normalized=True]             0.121947  0.033552  0.077895   0.167120  0.127345
RBF[kernel=cubic,tail=constant,normalized=True]              0.125348  0.037982  0.072579   0.169413  0.140753
RBF[kernel=cubic,tail=linear,normalized=True]                0.125474  0.038609  0.071268   0.169843  0.137987
RBF[kernel=cubic,tail=linear+quadratic,normalized=True]      0.126070  0.039773  0.071279   0.171862  0.135489

Kriging

import matplotlib.pyplot as plt
import numpy as np

from ezmodel.models.kriging import Kriging
from ezmodel.util.sample_from_func import square_function

model = Kriging(regr="linear",
                corr="gauss",
                ARD=False)

# create some data to test this model on
X, y, _X, _y = square_function(100, 20)

# let the model fit the data
model.fit(X, y)

# predict the data using the model
y_hat = model.predict(_X)

# predict the data using the model
_X = _X[np.argsort(_X[:, 0])]
y_hat = model.predict(_X)

plt.scatter(X, y, label="Data")
plt.plot(_X, y_hat, color="black", label="RBF")
plt.legend()
plt.show()

RBF

import matplotlib.pyplot as plt
import numpy as np

from ezmodel.models.rbf import RBF
from ezmodel.util.sample_from_func import sine_function

rbf = RBF(kernel="gaussian")

# create some data to test this model on
X, y, _X, _y = sine_function(20, 200)

# let the model fit the data
rbf.fit(X, y)

# predict the data using the model
y_hat = rbf.predict(_X)

# predict the data using the model
_X = _X[np.argsort(_X[:, 0])]
y_hat = rbf.predict(_X)

plt.scatter(X, y, label="Data")
plt.plot(_X, y_hat, color="black", label="RBF")
plt.legend()
plt.show()

Contact

Feel free to contact us if you have any question:

Julian Blank (blankjul [at] msu.edu)
Michigan State University
Computational Optimization and Innovation Laboratory (COIN)
East Lansing, MI 48824, USA