classdef particle < handle
properties
mass
position
velocity
fixed
lifespan
age = 0
force = [0 0 0]
graphics_handle
end
methods
function Particle = particle (Particle_System, mass, position, velocity, fixed, lifespan)
%PARTICLE Particle object constructor.
%
% Examples
%
% P = PARTICLE (PS) creates particle P with default
% properties:
% mass: 1
% position: [0 0 0]
% velocity: [0 0 0]
% fixed: false
% life span: inf
% and appends it to the particle system PS
%
% P = PARTICLE (PS, M, PP, V, F, L) creates particle P with
% the following properties:
% mass: M
% position: PP (PP must be a 1-by-3 vector)
% velocity: V (V must be a 1-by-3 vector)
% fixed: F (F must be false (or 0) for a free or true (or 1)
% for a fixed particle)
% life span: L
% and appends it to the particle system PS
% Copyright 2008-2008, buchholz.hs-bremen.de
if nargin == 1
mass = 1;
position = [0, 0, 0];
velocity = [0, 0, 0];
fixed = false;
lifespan = inf;
end
Particle.mass = mass;
Particle.position = position;
Particle.velocity = velocity;
Particle.fixed = fixed;
Particle.lifespan = lifespan;
Particle.append (Particle_System);
end
function clear_force (Particle)
%CLEAR_FORCE Clear particle force accumulator.
%
% Example
% CLEAR_FORCE (P) clears the force accumulator of the particle P.
%
% See also add_force.
% Copyright 2008-2008, buchholz.hs-bremen.de
Particle.force = [0 0 0];
end
function add_force (Particle, force)
%ADD_FORCE Add force to particle force accumulator.
%
% Example
%
% ADD_FORCE (P, F) adds the force F to the force accumulator of the
% particle P.
%
% See also clear_force.
% Copyright 2008-2008 buchholz.hs-bremen.de
Particle.force = Particle.force + force;
end
function delete (Particle)
%DELETE Delete particle.
%
% Example
%
% DELETE (P) deletes the particle P.
% Copyright 2008-2008 buchholz.hs-bremen.de
if ishandle (Particle.graphics_handle)
delete (Particle.graphics_handle)
end
end
function update_graphics_position (Particle)
%UPDATE_GRAPHICS_POSITION Update the graphical particle representation.
%
% Example
%
% UPDATE_GRAPHICS_POSITION (P) updates the position of the
% graphical representation of the particle P.
% Copyright 2008-2008 buchholz.hs-bremen.de
set (Particle.graphics_handle, ...
'xdata', Particle.position(1), ...
'ydata', Particle.position(2), ...
'zdata', Particle.position(3));
end
function set.fixed (Particle, fixed)
%SET.FIXED Pin a particle to its position.
%
% Examples
%
% P.FIXED = TRUE pins the particle P to its current position
% and changes its graphical representation to an asterisk.
%
% P.FIXED = FALSE makes P a free particle and changes its
% graphical representation to a dot.
% Copyright 2008-2008 buchholz.hs-bremen.de
Particle.fixed = fixed;
if Particle.fixed
set (Particle.graphics_handle, 'markersize', 10, 'marker', '*')
else
set (Particle.graphics_handle, 'markersize', 30, 'marker', '.')
end
end
function set.position (Particle, position)
%SET.POSITION Set the position of a particle.
%
% Examples
%
% P.POSITION = NEW_POSITION sets the current position of the
% particle P to NEW_POSITION.
% Copyright 2008-2008 buchholz.hs-bremen.de
Particle.position = position;
Particle.update_graphics_position;
end
end
methods (Access = 'private')
function append (Particle, Particle_System)
%APPEND Append particle to particle system.
%
% Example
%
% APPEND (P, PS) appends the particle P to the
% particle system PS.
% Copyright 2008-2008 buchholz.hs-bremen.de
figure (Particle_System.graphics_handle)
Particle.graphics_handle = ...
line ( ...
Particle.position(1), ...
Particle.position(2), ...
Particle.position(3), ...
'color', [1 0 0], ...
'markersize', 30, ...
'marker', '.');
if Particle.fixed
set (Particle.graphics_handle, 'markersize', 10, 'marker', '*')
end
Particle_System.particles = [Particle_System.particles, Particle];
end
end
end
