Efficient random sampling via linear interpolation.
When you have a density function, but you would like to create a set of sample points from that density function, you can use linear interpolate sampling. Using the evaluation of the density at the two endpoints of 1D interval, or the four corners of a 2D rectangle, or generally the $2^k$ vertices of a $k$-dimensional hyperbox (or a series of such hyperboxes, e.g., the cells of a $k$-dimensional grid), linear interpolant sampling is a technique to draw random samples within the hyperbox. lintsampler
provides a Python implementation of this.
See the documentation or our paper for further details.
Three ways of installing lintsampler
:
pip
:
pip install lintsampler
conda
:
conda install -c conda-forge lintsampler
Simply cloning this repository.
If you have a density function, such as this multi-modal 1d pdf with the bulk of the density between -7 and 7,
import numpy as np
def gmm_pdf(x):
mu = np.array([-3.0, 0.5, 2.5])
sig = np.array([1.0, 0.25, 0.75])
w = np.array([0.4, 0.25, 0.35])
return np.sum([w[i] * norm.pdf(x, mu[i], sig[i]) for i in range(3)], axis=0)
lintsampler
can efficiently draw samples from it on some defined interval (here a 100-point grid between -7 and 7):
from lintsampler import LintSampler
grid = np.linspace(-7,7,100)
samples = LintSampler(grid,pdf=gmm_pdf).sample(N=10000)
Making a histogram of the resulting samples and comparing to the input density function shows good agreement -- and we can do even better by increasing the resolution.
See this page of the documentation for a more detailed explanation of this example.
Complete documentation, including more example notebooks, is available at lintsampler.readthedocs.io/.
If using lintsampler
for a research publication, please cite our paper.
lintsampler
is available under the MIT license. See the LICENSE file for specifics.