Posts

Accelerated Longitudinal and Multiple Group Designs in ctsem

This post is motivated by a recent question about how to handle accelerated longitudinal designs in ctsem. In these designs growth over …

What is Heterogeneity, Really?

It seems a quite common understanding that unit level ‘heterogeneity’ (i.e. individual differences) when using statistical models …

Dynamic Systems Modeling in Psychology

What is a dynamic system? Why are they interesting? How do we take bits of the bumbling buzzing confusion around us and pack them into …

Latent growth curves, state dependent error.

Latent growth curves are a nice, relatively straightforward model for estimating overall patterns of change from multiple, noisy, …

Kalman filter vs smoother -- Missing data imputation in ctsem.

ctsem is R software for statistical modelling using hierarchical state space models, of discrete or continuous time formulations, with …

ctsem Quick Start -- Sunspots Damped Linear Oscillator

ctsem is R software for statistical modelling using hierarchical state space models, of discrete or continuous time formulations, with …

Binary data in state space models

Generate some data Here we specify a bivariate latent process where the 1st process affects the 2nd, and there are stable individual …

Representations of Dynamic Systems -- Problems of SEM / Regression / Discrete Time

Representing Dynamic Systems Building on from the dynamic systems intro in a previous post, to build formal models of dynamic systems, …