René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"transform from center-of-mass frame to lab frame","articleBody":"Hi Dr. Issac Lenton,\r\n\r\nI'm trying to do some scattering calculations with OTT in MATLAB. I'm able to follow the beam_visualization.m example and calculate the scattered fields when the trap beam (a gaussian beam) is offset from the particle. As I understand it, everything is in the particle's center-of-mass frame. I want to transform the far-field solutions back into the lab frame after the scattering calculation. Could you advise how I should proceed? Currently, translation in Y (using .translateXyz) seems to also cause some tilt in the far-field solutions without applying any scattering matrix. I attached a plot to show how the beam profile in blue in the translated Y dimension looks skewed in the particle's COM frame in the far field regime. I want to be in a rest frame of this incoming trap beam, where I think the beam profiles in any XY planes would look translated and not skewed. Any suggestions are appreciated. \r\n\r\n![backscatteredCOM](https://github.com/ilent2/ott/assets/32280225/af1f92d9-4623-493c-9570-1309c1b178b5)\r\n\r\nThanks,\r\nYuqi\r\n\r\n","author":{"url":"https://github.com/yuqizhuyqz","@type":"Person","name":"yuqizhuyqz"},"datePublished":"2023-08-11T20:48:42.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/53/ott/issues/53"}