particle.data-class: Particle trajectory data class

In FastGaSP: Fast and Exact Computation of Gaussian Stochastic Process

Particle trajectory data class

Description

S4 class for storing and analyzing particle trajectory data from both simulations and experimental observations. This class supports different models including Vicsek and can handle both position and velocity data along with optional angle information and particle tracking capabilities for experimental data.

Objects from the Class

Objects of this class can be created in two ways:

• For simulation data: Using simulate_particle that computes particle trajectories under physical models

• For experimental data: Using trajectory_data to save particle trajectories while handling varying numbers of particles between time steps

Slots

px_list:

Object of class list. List of x-positions at each time step.

py_list:

Object of class list. List of y-positions at each time step.

vx_list:

Object of class list. List of x-velocities at each time step.

vy_list:

Object of class list. List of y-velocities at each time step.

theta_list:

Object of class listOrNULL. Optional list of particle velocity angles at each time step.

particle_tracking:

Object of class listOrNULL. List of data frames containing particle mappings between consecutive frames (primarily for experimental data).

data_type:

Object of class character. Type of data: either "simulation" or "experiment".

n_particles:

Object of class numeric. Number of particles (constant for simulation data, or a vector recording the number of particles at each time step for experimental data).

T_time:

Object of class numeric. Total number of time steps.

D_y:

Object of class numeric. Dimension of the output space.

model:

Object of class characterOrNULL. Type of particle interaction model (e.g., "Vicsek"). NULL for experimental data.

sigma_0:

Object of class numericOrNULL. Noise variance parameter used in the model. NULL for experimental data.

radius:

Object of class numericOrNULL. Interaction radius between particles. NULL for experimental data.

Methods

show:

Method for displaying summary information about the particle.data object.

fit:

Method for fitting the latent factor model to data using the IKF-CG algorithm, which returns a particle.est object containing estimated parameters and predictions. See fit.particle.data for detailed documentation.

Author(s)

Mengyang Gu [aut, cre], Xinyi Fang [aut], Yizi Lin [aut]

Maintainer: Mengyang Gu <[e-mail]>

References

Vicsek, T., Czirok, A., Ben-Jacob, E., Cohen, I., & Shochet, O. (1995). Novel type of phase transition in a system of self-driven particles, Physical Review Letters, 75(6), 1226.

Chat'e, H., Ginelli, F., Gr'egoire, G., Peruani, F., & Raynaud, F. (2008). Modeling collective motion: variations on the Vicsek model, The European Physical Journal B, 64(3), 451-456.

See Also

simulate_particle for simulating particle trajectories, trajectory_data for saving experimantal particle trajectories, fit.particle.data for model fitting methods

FastGaSP documentation built on April 4, 2025, 5:16 a.m.