gpOptimizer: Mini Application#

## First, install the right version of gpCAM, and matplotlib
#!pip install gpcam==8.3.5
#!pip install matplotlib

Setup#

import numpy as np
import matplotlib.pyplot as plt
from gpcam import GPOptimizer
import time

from itertools import product
x_pred1D = np.linspace(0,1,1000).reshape(-1,1)

Data Prep#

x = np.linspace(0,600,1000)
def f1(x):
    return np.sin(5. * x) + np.cos(10. * x) + (2.* (x-0.4)**2) * np.cos(100. * x)
 
x_data = np.random.rand(20).reshape(-1,1) 
y_data = f1(x_data[:,0]) + (np.random.rand(len(x_data))-0.5) * 0.5

plt.figure(figsize = (15,5))
plt.xticks([0.,0.5,1.0])
plt.yticks([-2,-1,0.,1])
plt.xticks(fontsize=20)
plt.yticks(fontsize=20)
plt.plot(x_pred1D,f1(x_pred1D), color = 'orange', linewidth = 4)
plt.scatter(x_data[:,0],y_data, color = 'black')

<matplotlib.collections.PathCollection at 0x7fbd7886d690>
../_images/048fe486c6828e01e648677f72e8fd2ded688f38a97ab29d8eaff29fb03ee5fd.png

GP Setup#

my_gp = GPOptimizer(x_data,y_data,)
my_gp.train()

train_at = [10,20,30] #optional
for i in range(100):
    new = my_gp.ask(np.array([[0.,1.]]))["x"]
    my_gp.tell(new, f1(new).reshape(len(new)))
    if i in train_at: my_gp.train()

/home/marcus/VirtualEnvironments/gpcam_dev/lib/python3.11/site-packages/fvgp/gp.py:276: UserWarning: Hyperparameters initialized to a vector of ones.
  warnings.warn("Hyperparameters initialized to a vector of ones.")
/home/marcus/VirtualEnvironments/gpcam_dev/lib/python3.11/site-packages/fvgp/gp.py:310: UserWarning: No noise function or measurement noise provided. Noise variances will be set to (0.01 * mean(|y_data|))^2.
  self.likelihood = GPlikelihood(self.data,
/home/marcus/VirtualEnvironments/gpcam_dev/lib/python3.11/site-packages/fvgp/gp.py:611: UserWarning: Default hyperparameter_bounds initialized because none were provided. This will fail for custom kernel, mean, or noise functions
  warnings.warn("Default hyperparameter_bounds initialized because none were provided. "
/home/marcus/VirtualEnvironments/gpcam_dev/lib/python3.11/site-packages/fvgp/gp_mcmc.py:197: RuntimeWarning: overflow encountered in exp
  metr_ratio = np.exp(prior_evaluation_x_star + likelihood_star -

#let's make a prediction
x_pred = np.linspace(0,1,1000)

mean1 = my_gp.posterior_mean(x_pred.reshape(-1,1))["m(x)"]
var1 =  my_gp.posterior_covariance(x_pred.reshape(-1,1), variance_only=False, add_noise=True)["v(x)"]
plt.figure(figsize = (16,10))
plt.plot(x_pred,mean1, label = "posterior mean", linewidth = 4)
plt.plot(x_pred1D,f1(x_pred1D), label = "latent function", linewidth = 4)
plt.fill_between(x_pred, mean1 - 3. * np.sqrt(var1), mean1 + 3. * np.sqrt(var1), alpha = 0.5, color = "grey", label = "var")
plt.scatter(my_gp.x_data,my_gp.y_data, color = 'black')


##looking at some validation metrics
print(my_gp.rmse(x_pred1D,f1(x_pred1D).flatten()))
print(my_gp.crps(x_pred1D,f1(x_pred1D).flatten()))

0.054709649555790815
(np.float64(0.031239862711767454), np.float64(0.03517905080402679))
../_images/a58b0b904d714e8181fa02ecd99bb7e1ed709ae9bb716e237c9f7b00a01139d1.png
On this page