Timeline for Searching extreme points of polyhedron
Current License: CC BY-SA 4.0
22 events
| when toggle format | what | by | license | comment | |
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| Apr 22, 2019 at 21:36 | comment | added | Reinderien | Given the number of comments already, let's please continue this at chat.stackexchange.com/rooms/92760/… | |
| Apr 22, 2019 at 21:21 | comment | added | Andrey Lovyagin | @AJD Yep, I was reading about it, when was writing the code, thank you. I will try to dig deeper into this theme. | |
| Apr 22, 2019 at 21:10 | comment | added | Andrey Lovyagin | @Reinderien I wrote it by hand on example to made it more explicit: imgur.com/oZF9uf4 | |
| Apr 22, 2019 at 19:50 | comment | added | AJD | Look up "convex hull" to find examples of getting the boundaries (extreme points) of a series of points (e.g. the vertices of your polyhedral) | |
| Apr 22, 2019 at 16:19 | comment | added | Reinderien |
Can you explicitly define w, x, u and U as seen in your docs?
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| Apr 22, 2019 at 9:00 | history | tweeted | twitter.com/StackCodeReview/status/1120251126107054081 | ||
| Apr 22, 2019 at 7:17 | comment | added | Andrey Lovyagin | @Reinderien Thank you for your report. I will try to update this program to work with latest preinstalled numpy (mine is 1.15.4). From the math point: I am making all combinations of matrix A NxN (where N is a number of dimensions). Then I am solving each system of equations for the same combinations of vector b and checking the answers if they are really an extreme points. | |
| Apr 22, 2019 at 7:13 | comment | added | qwr | I'm fairly certain it's linear programming | |
| Apr 22, 2019 at 7:12 | comment | added | Andrey Lovyagin | @vnp I was using this article to understand it from math point: cs.bgu.ac.il/~ilp152/wiki.files/hwk2.pdf | |
| Apr 22, 2019 at 7:11 | comment | added | Andrey Lovyagin | @Reinderien I was using this article (cs.bgu.ac.il/~ilp152/wiki.files/hwk2.pdf) to understand what is polyhedron. And I am using n-dimensions (that means you can put any positive integer number in the first and second argument of the function). For the solving system of equations (Ax=b) I am using numpy.linalg.solve(), but before I am checking if matrix A, not a degenerate matrix. I don't know what is polytope, but I google it, and now I am interested :0 | |
| Apr 22, 2019 at 3:22 | history | became hot network question | |||
| Apr 22, 2019 at 3:15 | history | edited | 200_success | CC BY-SA 4.0 |
added 87 characters in body; edited tags
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| Apr 22, 2019 at 0:52 | comment | added | Reinderien | This occurs for both Python 3.7 and 2.7. However, I'm using numpy-1.16.2, which I strongly suggest you adopt. | |
| Apr 22, 2019 at 0:48 | comment | added | Reinderien |
@AndrewLovyagin When I run, I get this error: TypeError: No loop matching the specified signature and casting was found for ufunc solve1
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| Apr 22, 2019 at 0:46 | answer | added | Reinderien | timeline score: 5 | |
| Apr 22, 2019 at 0:34 | comment | added | vnp | @Reinderien Agreed. Still deciphering. | |
| Apr 22, 2019 at 0:33 | comment | added | Reinderien | @vnp That's kind of what I guessed, and if that's the case, linear programming is a quite well-established field already - with some stuff built right into scipy. | |
| Apr 22, 2019 at 0:32 | comment | added | vnp |
@Reinderien I am still in the process of deciphering the question. I have a math background, and I share the mother tongue with OP. My impression is that by extremal points OP means the vertices of a simplex where a certain linear form (defined by A, b, and the condition) achieves an extremum. I could be wrong.
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| Apr 21, 2019 at 23:22 | comment | added | Reinderien | "there is still no code in public for searching extreme points for polyhedral with n dimensions" - I can nearly guarantee that that isn't the case. | |
| Apr 21, 2019 at 23:21 | comment | added | Reinderien | Can you provide some more information on what exactly is going on, from a math standpoint? Is this actually a polyhedron, or a polytope? In how many dimensions? By "extreme", what do you mean? Euclidean norm from (the origin, an arbitrary point)? | |
| Apr 21, 2019 at 23:00 | review | First posts | |||
| Apr 21, 2019 at 23:05 | |||||
| Apr 21, 2019 at 22:57 | history | asked | Andrey Lovyagin | CC BY-SA 4.0 |