Score Change of Variables
- URL: http://arxiv.org/abs/2412.07904v3
- Date: Mon, 24 Feb 2025 17:56:03 GMT
- Title: Score Change of Variables
- Authors: Stephen Robbins,
- Abstract summary: We show that for a smooth, invertible transformation $mathbfy = phi(mathbfx)$, the transformed score function $nabla_mathbfy log q(mathbfy)$ can be expressed directly in terms of $nabla_mathbfx log p(mathbfx)$.<n>We also introduce generalized sliced score matching, extending traditional sliced score matching from linear projections to arbitrary smooth transformations.
- Score: 0.0
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: We derive a general change of variables formula for score functions, showing that for a smooth, invertible transformation $\mathbf{y} = \phi(\mathbf{x})$, the transformed score function $\nabla_{\mathbf{y}} \log q(\mathbf{y})$ can be expressed directly in terms of $\nabla_{\mathbf{x}} \log p(\mathbf{x})$. Using this result, we develop two applications: First, we establish a reverse-time It\^o lemma for score-based diffusion models, allowing the use of $\nabla_{\mathbf{x}} \log p_t(\mathbf{x})$ to reverse an SDE in the transformed space without directly learning $\nabla_{\mathbf{y}} \log q_t(\mathbf{y})$. This approach enables training diffusion models in one space but sampling in another, effectively decoupling the forward and reverse processes. Second, we introduce generalized sliced score matching, extending traditional sliced score matching from linear projections to arbitrary smooth transformations. This provides greater flexibility in high-dimensional density estimation. We demonstrate these theoretical advances through applications to diffusion on the probability simplex and empirically compare our generalized score matching approach against traditional sliced score matching methods.
Related papers
- Spanning the Visual Analogy Space with a Weight Basis of LoRAs [84.16188433935494]
Visual analogy learning enables image manipulation through demonstration rather than textual description.<n>LoRWeB specializes the model for each analogy task at inference time through dynamic composition of learned transformation primitives.<n>We introduce two key components: (1) a learnable basis of LoRA modules, to span the space of different visual transformations, and (2) a lightweight encoder that dynamically selects and weighs these basis LoRAs.
arXiv Detail & Related papers (2026-02-17T17:02:38Z) - Conditional Score Learning for Quickest Change Detection in Markov Transition Kernels [15.70380155219054]
We learn the conditional score $nabla_mathbfy log p(mathbfy|mathbfx)$ directly from sample pairs.<n>We develop a score-based CUSUM procedure that uses conditional Hyvarinen score differences to detect changes in the kernel.
arXiv Detail & Related papers (2025-11-06T01:07:36Z) - Injecting Measurement Information Yields a Fast and Noise-Robust Diffusion-Based Inverse Problem Solver [20.959606647379356]
We propose to estimate the conditional posterior mean $mathbbE [mathbfx_t, mathbfy]$.<n>The resulting prediction can be integrated into any standard sampler, resulting in a fast and memory-efficient inverse solver.
arXiv Detail & Related papers (2025-08-05T00:01:41Z) - Fast Convergence for High-Order ODE Solvers in Diffusion Probabilistic Models [5.939858158928473]
Diffusion probabilistic models generate samples by learning to reverse a noise-injection process that transforms data into noise.<n>Reformulating this reverse process as a deterministic probability flow ordinary differential equation (ODE) enables efficient sampling using high-order solvers.<n>Since the score function is typically approximated by a neural network, analyzing the interaction between its regularity, approximation error, and numerical integration error is key to understanding the overall sampling accuracy.
arXiv Detail & Related papers (2025-06-16T03:09:25Z) - Outsourced diffusion sampling: Efficient posterior inference in latent spaces of generative models [65.71506381302815]
We propose amortize the cost of sampling from a posterior distribution of the form $p(mathbfxmidmathbfy) propto p_theta(mathbfx)$.
For many models and constraints of interest, the posterior in the noise space is smoother than the posterior in the data space, making it more amenable to such amortized inference.
arXiv Detail & Related papers (2025-02-10T19:49:54Z) - Inverse Entropic Optimal Transport Solves Semi-supervised Learning via Data Likelihood Maximization [65.8915778873691]
conditional distributions is a central problem in machine learning.<n>We propose a new paradigm that integrates both paired and unpaired data.<n>We show that our approach can theoretically recover true conditional distributions with arbitrarily small error.
arXiv Detail & Related papers (2024-10-03T16:12:59Z) - Inverting the Leverage Score Gradient: An Efficient Approximate Newton Method [10.742859956268655]
This paper aims to recover the intrinsic model parameters given the leverage scores gradient.
We specifically scrutinize the inversion of the leverage score gradient, denoted as $g(x)$.
arXiv Detail & Related papers (2024-08-21T01:39:42Z) - Projection by Convolution: Optimal Sample Complexity for Reinforcement Learning in Continuous-Space MDPs [56.237917407785545]
We consider the problem of learning an $varepsilon$-optimal policy in a general class of continuous-space Markov decision processes (MDPs) having smooth Bellman operators.
Key to our solution is a novel projection technique based on ideas from harmonic analysis.
Our result bridges the gap between two popular but conflicting perspectives on continuous-space MDPs.
arXiv Detail & Related papers (2024-05-10T09:58:47Z) - Near Optimal Heteroscedastic Regression with Symbiotic Learning [29.16456701187538]
We consider the problem of heteroscedastic linear regression.
We can estimate $mathbfw*$ in squared norm up to an error of $tildeOleft(|mathbff*|2cdot left(frac1n + left(dnright)2right)$ and prove a matching lower bound.
arXiv Detail & Related papers (2023-06-25T16:32:00Z) - Score-based Continuous-time Discrete Diffusion Models [102.65769839899315]
We extend diffusion models to discrete variables by introducing a Markov jump process where the reverse process denoises via a continuous-time Markov chain.
We show that an unbiased estimator can be obtained via simple matching the conditional marginal distributions.
We demonstrate the effectiveness of the proposed method on a set of synthetic and real-world music and image benchmarks.
arXiv Detail & Related papers (2022-11-30T05:33:29Z) - Optimal Gradient Sliding and its Application to Distributed Optimization
Under Similarity [121.83085611327654]
We structured convex optimization problems with additive objective $r:=p + q$, where $r$ is $mu$-strong convex similarity.
We proposed a method to solve problems master to agents' communication and local calls.
The proposed method is much sharper than the $mathcalO(sqrtL_q/mu)$ method.
arXiv Detail & Related papers (2022-05-30T14:28:02Z) - Generalization Bounds for Gradient Methods via Discrete and Continuous
Prior [8.76346911214414]
We show a new high probability generalization bound of order $O(frac1n + fracL2n2sum_t=1T(gamma_t/varepsilon_t)2)$ for gradient Langevin Dynamics (GLD)
We can also obtain new bounds for certain variants of SGD.
arXiv Detail & Related papers (2022-05-27T07:23:01Z) - Statistical Inference of Constrained Stochastic Optimization via Sketched Sequential Quadratic Programming [53.63469275932989]
We consider online statistical inference of constrained nonlinear optimization problems.
We apply the Sequential Quadratic Programming (StoSQP) method to solve these problems.
arXiv Detail & Related papers (2022-05-27T00:34:03Z) - On Submodular Contextual Bandits [92.45432756301231]
We consider the problem of contextual bandits where actions are subsets of a ground set and mean rewards are modeled by an unknown monotone submodular function.
We show that our algorithm efficiently randomizes around local optima of estimated functions according to the Inverse Gap Weighting strategy.
arXiv Detail & Related papers (2021-12-03T21:42:33Z) - Fast Margin Maximization via Dual Acceleration [52.62944011696364]
We present and analyze a momentum-based method for training linear classifiers with an exponentially-tailed loss.
This momentum-based method is derived via the convex dual of the maximum-margin problem, and specifically by applying Nesterov acceleration to this dual.
arXiv Detail & Related papers (2021-07-01T16:36:39Z) - Convergence of Sparse Variational Inference in Gaussian Processes
Regression [29.636483122130027]
We show that a method with an overall computational cost of $mathcalO(log N)2D(loglog N)2)$ can be used to perform inference.
arXiv Detail & Related papers (2020-08-01T19:23:34Z) - Linear Time Sinkhorn Divergences using Positive Features [51.50788603386766]
Solving optimal transport with an entropic regularization requires computing a $ntimes n$ kernel matrix that is repeatedly applied to a vector.
We propose to use instead ground costs of the form $c(x,y)=-logdotpvarphi(x)varphi(y)$ where $varphi$ is a map from the ground space onto the positive orthant $RRr_+$, with $rll n$.
arXiv Detail & Related papers (2020-06-12T10:21:40Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.