About

I’m an Assistant Professor in the Statistics Department of the Bailey College of Science and Mathematics at Cal Poly SLO. My work connects statistical methodology for complex structured data with substantive scientific applications. I am interested in time series analysis, model selection, high-dimensional data, and biological and ecological applications.

Vita

California Polytechnic State University, San Luis Obispo

Assistant Professor | 2023-present

University of California, Santa Barbara

Visiting Assistant Professor | 2020-2023

Oregon State University

Ph.D. Statistics | 2020

M.S. Statistics | 2017

Portland State University

Graduate Certificate in Applied Statistics | 2015

Reed College

B.A. Philosophy | 2011

Current Projects

AY26-27. Working titles.

  • Modeling Variation in Rattlesnake Populations across Geographic and Climatic Gradients with Multilevel Functional Regression. This project uses a hierarchical functional regression framework to model daily physiological body temperature curves from individual rattlesnakes in multiple populations across western North America. The project develops methods for scalable estimation – the data comprise over one million hourly observations from hundreds of individuals across roughly twenty sites – and examines how environmental and interannual variation shapes physiological responses. Collaboration with Emily Taylor (Biology) and Haley Moniz (Biology), with student contributors Nicole Yee (Statistics) and Allen Choi (Statistics).

  • Borrowing strength across taxonomic levels for inference of ecological association networks from amplicon sequencing data. This work develops a taxonomy-aware method for estimating ecological association networks from amplicon sequencing data that jointly estimates networks at multiple taxonomic levels and borrows information across levels to improve inference at biologically meaningful resolution. A cross-level consistency penalty in the joint estimation objective allows finer-level signals with strong coarser-level aggregate support to be selected more easily, allowing recovery of network structure below the detection thresholds of standard approaches while reducing false discoveries. Student contributors Carson Neubert (Statistics), Eden Schott (Statistics), Maleah Townsend (Environmental Protection & Management), Julien Fiechter (Statistics).

Selected Papers

Recent and current work; see CV for a full publication list. Annotations: co-leads\(^\S\); students\(^\dagger\).

  • T.D. Ruiz, A.J. Seifert\(^\dagger\), E. Hamilton\(^\dagger\), C.M. Mispagel\(^\dagger\), J. Garcia\(^\dagger\), E.E. Bockmon. Affine-Invariant Inference for Local Trend Similarity in Nonstationary Time Series, with Application to Biogeochemical Decoupling in an Estuary. In preparation.

  • C.C. Pawlak, R.J. Kenny, T.D. Ruiz, J.C. Schedler, K. Veerasingam\({^\dagger}\), A. Pineda, G.A. Fricker, T.W. Gillespie, M.K. Ritter, J.M. Yost. Integrating Arborist Records and Remote Sensing to Improve Urban Tree Allometric Equations and Benefit Estimates. In preparation.

  • E.V. Satterthwaite\(^\S\), T.D. Ruiz\(^\S\), N.V. Patin, M.N. Alksne, L. Thomas, J. Dinasquet, R.H. Lampe, N.A. Patrick\(^\dagger\), K.G. Chan\(^\dagger\), A.E. Allen, S. Baumann-Pickering, B.X. Semmens (2026). Microbial and small plankton environmental DNA predicts density of blue, fin, and humpback whales in the southern California bight. PLOS One. [paper] [code] [data]

  • T. D. Ruiz, S. Bhattacharyya, S. C. Emerson (2025). Sparse estimation of parameter support sets for generalized vector autoregressions by resampling and model aggregation. Journal of Statistical Computation and Simulation. [paper] [code] [preprint]

  • H. A. Moniz, J. H. Buck, H. L. Crowell, S. M. Goetz, T. D. Ruiz, S. M. Boback, E. N. Taylor (2024). High thermal quality rookeries facilitate high thermoregulatory accuracy in pregnant female rattlesnakes. Journal of Thermal Biology. [paper] [code] [data]

Recent Courses

See CV for full teaching record.

Current Students

In alphabetical order by graduation year. See CV for past students.

Thesis

  • Emi Degembe, B.S/M.S. Statistics 2027
  • Visruth Kandali, B.S./M.S. Statistics 2027
  • Alea Seifert, B.S./M.S. Statistics 2027
  • Nicole Yee, B.S/M.S. Statistics 2027

Research

  • Otis Hunt, B.S./M.S. Statistics 2028
  • Catherine Mispagel, B.S./M.S. Statistics 2028
  • Carson Neubert, B.S./M.S. Statistics 2028