most recent 30 from http://mathoverflow.net 2013-05-19T03:59:19Z http://mathoverflow.net/feeds/user/13479 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/59870/algorithm-to-calculate-exploded-views-for-cad Davido 2011-03-28T17:35:49Z 2011-03-30T10:58:19Z

<p>I'm making a program to view 3D CAD models and would like to build in automated exploded views. All the assemblies that will be viewed are axi-symmetric. Some may not be, but the majority are. I'd like to figure out an algorithm for automatically moving parts in an assembly into an exploded view position. Here is an example of what I want to achieve through an algorithm (Sorry, don't have enough reputation to embed images):</p> <p><a href="http://i1238.photobucket.com/albums/ff487/davidohyer/exploded.jpg?t=1301331812" rel="nofollow">http://i1238.photobucket.com/albums/ff487/davidohyer/exploded.jpg?t=1301331812</a></p> <p>The only value I have to work with is the center of the bounding box of each part. If more information than that is needed, I can calculate more information, but it seems like it should be sufficient. The rough approach I have in mind is to calculate a vector from the origin of the assembly to the center of each part along the axi-symmetric axis, then calculate a radial vector to the center of the part with respect to the center axis. From there, I'd need to figure out some calculation that would be able to scale the position of each part along some combination of those two vectors. That's the part where I'm not quite sure what direction to go with this. The image I've included shows the exact functionality I'd like, but I want to be able to scale the position by any float value to expand or contract the exploded view, with 1.0 being the original assembled model. Any ideas?</p>

http://mathoverflow.net/questions/57715/remap-fft-frequency-bin-distribution Davido 2011-03-07T18:46:40Z 2011-03-25T01:22:14Z

<p>I've coded up the FFT for a dataset I'm working with. My intent is to create a waterfall plot of the result, but the problem I'm running into is if I change my input data size, then I get a different number of frequency bins. Currently I'm just making my input dataset twice the size of the number of pixels I need to map to. I'm trying to figure out a way to map the frequency bins of any data set size to a specific number of pixels. For example, mapping an array of 500 values to an array that is 1250 elements long. It would be nice to have the option to perform linear and non-linear interpolation on the data mapping. I also might need to go the other way, say to map the values to an array that is 300 elements long. I'm not a math major and am coming up with a blank on this one.</p>

http://mathoverflow.net/questions/59870/algorithm-to-calculate-exploded-views-for-cad Davido 2011-03-28T22:13:11Z 2011-03-28T22:13:11Z

@Ryan: I tried out the graphicdesign page, and it seems that it is only for graphic artists, they don't like technical questions over there. @Joseph: That seems like it might be a good place to look. I'll check it out. Thanks.

http://mathoverflow.net/questions/59870/algorithm-to-calculate-exploded-views-for-cad Davido 2011-03-28T18:12:52Z 2011-03-28T18:12:52Z

I figured this would fit here since it is dealing with the mathematical aspect of an exploded view. One paper that is along the lines of where I'm headed is here: <a href="http://vis.berkeley.edu/papers/exview3D/exview3D-SIG08.pdf" rel="nofollow">vis.berkeley.edu/papers/exview3D/&hellip;</a>

http://mathoverflow.net/questions/57715/remap-fft-frequency-bin-distribution Davido 2011-03-17T18:48:13Z 2011-03-17T18:48:13Z

Currently there is no model, I'm working on developing a model. I would like to set up a method where I can correlate rock types to specific frequency distribution patterns and see if I can manage to get some repeatable results for specific hardnesses/porosity of rock types. I was thinking it might be kind of similar to voice recognition algorithms, but the rock response while breaking it is the voice I would be using as input. Any ideas?

http://mathoverflow.net/questions/57715/remap-fft-frequency-bin-distribution Davido 2011-03-09T15:39:55Z 2011-03-09T15:39:55Z

I'm designing a program that will allow me to listen to a drilling tool as it is breaking through solid rock and monitor the frequency spectrum of the rock response through an accelerometer. I'm trying to be able to identify different rock types/properties based on frequency content while drilling.