{"id":4891,"date":"2013-11-01T09:00:42","date_gmt":"2013-11-01T13:00:42","guid":{"rendered":"https:\/\/blogs.mathworks.com\/pick\/?p=4891"},"modified":"2013-10-31T08:22:36","modified_gmt":"2013-10-31T12:22:36","slug":"comet3-with-speed-control","status":"publish","type":"post","link":"https:\/\/blogs.mathworks.com\/pick\/2013\/11\/01\/comet3-with-speed-control\/","title":{"rendered":"Comet3 with Speed Control"},"content":{"rendered":"\r\n\r\n

Jiro<\/a>'s pick this week is 3D Comet Plot<\/a> by Nick<\/a>.<\/p>

As a continuation to one of my previous posts, on multi-line comet plots<\/a>, this submission extends comet3<\/tt><\/a> to give the user ability to control the length of the tail, the speed of the animation, and the style of the head and tail of the comet. comet<\/tt> and comet3<\/tt> are useful functions, because these are functions that take similar type of input as other plotting functions and have animation built into them. I have used both of these functions in the past, but as computers became faster, the animation became too fast to view. That's why I really like the ability of PlotComet_3D<\/tt> to control the speed.<\/p>

Here's what comet3<\/tt> looks like.<\/p>

t = -pi:pi\/300:pi;\r\nx = sin(5*t);\r\ny = cos(3*t);\r\nz = t;\r\n<\/pre>
comet3(x, y, z)\r\n<\/pre>
\"\" <\/p>
By using Nick's PlotComet_3D<\/tt>, you can specify the speed in frequency, allowing for a consistent animation regardless of processing speed. Here, I'm also specifying a particular marker for the head of the comet.<\/p>
% Define marker style for the head of the comet<\/span>\r\nHead = struct(...<\/span>\r\n    'Marker'<\/span>, 'p'<\/span>, ...<\/span>\r\n    'MarkerSize'<\/span>, 10, ...<\/span>\r\n    'MarkerEdgeColor'<\/span>, 'b'<\/span>, ...<\/span>\r\n    'MarkerFaceColor'<\/span>, 'b'<\/span>);\r\n<\/pre>
% Animate at 100 Hz, tail length of 30<\/span>\r\nPlotComet_3D(x, y, z, ...<\/span>\r\n    'Frequency'<\/span>, 100, ...<\/span>\r\n    'blockSize'<\/span>, 30, ...<\/span>\r\n    'headFormat'<\/span>, Head);\r\n<\/pre>
\"\" <\/p>
Comments<\/b><\/p>
If you have used comet<\/tt> or comet3<\/tt> in the past and stopped using it because the animation has gotten too fast, give this a try. Let us know what you think here<\/a> or leave a comment<\/a> for Nick.<\/p>