ParticleLocalAccessBase¶

class hoomd.data.ParticleLocalAccessBase(state)¶

Directly access particle data in the simulation state.

Note

Changing some attributes (such as velocity and acceleration) may not alter the trajectory of the system as you would expect. The md.Integrator is responsible for integrating the equations of motion and manages the values in these arrays.

See also

typeid¶

The integer type of a particle.

Type:: (N_particles) HOOMDArray or HOOMDGPUArray of float

tag¶

The particle tags. Spatial sorting and MPI domain migration reorders particles in memory. The particle tag identifies each particle in the order it existed in the initial configuration.

Type:: (N_particles) HOOMDArray or HOOMDGPUArray of int

rtag¶

The particle reverse tags. For a given particle tag tag, i = particles.rtag[tag] is the array index holding that particle.

Type:: (N_particles_global) HOOMDArray or HOOMDGPUArray of int

position¶

Particle positions \([\mathrm{length}]\).

Type:: (N_particles, 3) HOOMDArray or HOOMDGPUArray of float

image¶

A count of how many times each particle crosses the periodic box boundaries.

Type:: (N_particles, 3) HOOMDArray or HOOMDGPUArray of int

velocity¶

Particle velocities \([\mathrm{velocity}]\).

Type:: (N_particles, 3) HOOMDArray or HOOMDGPUArray of float

acceleration¶

Particle accelerations \([\mathrm{velocity} \cdot \mathrm{time}^{-1}]\).

Type:: (N_particles, 3) HOOMDArray or HOOMDGPUArray of float

mass¶

Particle masses \([\mathrm{mass}]\).

Type:: (N_particles) HOOMDArray or HOOMDGPUArray of float

orientation¶

Particle orientations expressed as quaternions.

Type:: (N_particles, 4) HOOMDArray or HOOMDGPUArray of float

angmom¶

Particle angular momenta expressed as quaternions \([\mathrm{mass} \cdot \mathrm{velocity} \cdot \mathrm{length}]\).

Type:: (N_particles, 4) HOOMDArray or HOOMDGPUArray of float

moment_inertia¶

Particle principal moments of inertia \([\mathrm{mass} \cdot \mathrm{length}^2]\).

Type:: (N_particles, 3) HOOMDArray or HOOMDGPUArray of float

charge¶

Particle electrical charges \([\mathrm{charge}]\).

Type:: (N_particles) HOOMDArray or HOOMDGPUArray of float

diameter¶

Particle diameters \([\mathrm{length}]\).

Type:: (N_particles) HOOMDArray or HOOMDGPUArray of float

body¶

The id of the rigid body the particle is in.

Type:: (N_particles) HOOMDArray or HOOMDGPUArray of int

net_force¶

Net force on particle \([\mathrm{force}]\).

Type:: (N_particles, 3) HOOMDArray or HOOMDGPUArray of float

net_torque¶

Net torque on particle \([\mathrm{force} \cdot \mathrm{length}]\).

Type:: (N_particles, 3) HOOMDArray or HOOMDGPUArray of float

net_virial¶

Net virial on particle \([\mathrm{energy}]\).

Type:: (N_particles, 6) HOOMDArray or HOOMDGPUArray of float

net_energy¶

Net energy of a particle \([\mathrm{energy}]\).

Type:: (N_particles,) HOOMDArray or HOOMDGPUArray of float