hallucigenia + statistics:gams   5

Regression: Models, Methods and Applications - Ludwig Fahrmeir, Thomas Kneib, Stefan Lang, Brian Marx - Google Books
The aim of this book is an applied and unified introduction into parametric, non- and semiparametric regression that closes the gap between theory and application. The most important models and methods in regression are presented on a solid formal basis, and their appropriate application is shown through many real data examples and case studies. Availability of (user-friendly) software has been a major criterion for the methods selected and presented. Thus, the book primarily targets...
regression  statistics:regression  books  teaching:statistics  statistics:gams  statistics:spatial  to_read 
february 2018 by hallucigenia
mgcViz: visual tools for GAMs
The mgcViz R package offers visual tools for Generalized Additive Models (GAMs). The visualizations provided by mgcViz differs from those implemented in mgcv, in that most of the plots are based on ggplot2's powerful layering system. This has been implemented by wrapping several ggplot2 layers and integrating them with computations specific to GAM models. Further, mgcViz uses binning and/or sub-sampling to produce plots that can scale to large datasets (n = O(10^7)), and offers a variety of new methods for visual model checking/selection.
R  R_packages  visualization  statistics:gams  to_try  ggplot2  github 
december 2017 by hallucigenia
VAST: Spatio-temporal analysis of univariate or multivariate data, e.g., standardizing data for multiple species or stage

Is an R package for implementing a spatial delta-generalized linear mixed model (delta-GLMM) for multiple categories (species, size, or age classes) when standardizing survey or fishery-dependent data.
Builds upon a previous R package SpatialDeltaGLMM (public available here), and has unit-testing to automatically confirm that VAST and SpatialDeltaGLMM give identical results (to the 3rd decimal place for parameter estimates) for several varied real-world case-study examples
Has built in diagnostic functions and model-comparison tools
Is intended to improve analysis speed, replicability, peer-review, and interpretation of index standardization methods

This tool is designed to estimate spatial variation in density using spatially referenced data, with the goal of habitat associations (correlations among species and with habitat) and estimating total abundance for a target species in one or more years.
The model builds upon spatio-temporal delta-generalized linear mixed modelling techniques (Thorson Shelton Ward Skaug 2015 ICESJMS), which separately models the proportion of tows that catch at least one individual ("encounter probability") and catch rates for tows with at least one individual ("positive catch rates").
Submodels for encounter probability and positive catch rates by default incorporate variation in density among years (as a fixed effect), and can incorporate variation among sampling vessels (as a random effect, Thorson and Ward 2014) which may be correlated among categories (Thorson Fonner Haltuch Ono Winker In press).
Spatial and spatiotemporal variation are approximated as Gaussian Markov random fields (Thorson Skaug Kristensen Shelton Ward Harms Banante 2014 Ecology), which imply that correlations in spatial variation decay as a function of distance.
statistics:gams  statistics:time_series  statistics:fisheries  fisheries  fisheries:methods  statistics:bayesian  statistics:spatial  R_packages 
september 2017 by hallucigenia
R help - Use pcls in "mgcv" package to achieve constrained cubic spline
Use pcls in "mgcv" package to achieve constrained cubic spline. Hello everyone,          Dr. wood told me that I can adapting his example to force cubic spline to pass through certain...
statistics:gams  statistics:regression  statistics:constraints  advice  mgcv 
april 2017 by hallucigenia

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