Timeline for Spherical distance (Vincenty distance) between two geographic points [closed]
Current License: CC BY-SA 4.0
17 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 19, 2023 at 22:59 | vote | accept | Pierre Levoisin | ||
| May 17, 2023 at 17:38 | comment | added | Peilonrayz♦ | I've read over the linked meta post "moral, practical, and legal reasons" again and have some concerns around the topicality of your question. Your question could be on-topic, however you've not answered Mast. So the topicality of the question is neither clearly defined to be on or off topic. I've put the question on hold until the concerns have been resolved. | |
| May 17, 2023 at 17:38 | comment | added | Mast♦ | You copied the code, but I can find no indication you made it your own. You copied code that's part of a speed comparison ran in Python, hence the py namespace. When asked questions about the code, there is no response. Please read Why is only my own written code on-topic? | |
| May 17, 2023 at 17:28 | history | closed | Peilonrayz♦ | Not suitable for this site | |
| May 17, 2023 at 16:45 | history | removed from network questions | Mast♦ | ||
| May 17, 2023 at 15:43 | comment | added | qwr | All the comments here are hinting at an XY problem. Can you post your R code? It's very easy to get massive slowdowns in R if you're not careful with copies. Do you really need a complete distance matrix that is 1M x 1M? | |
| May 17, 2023 at 14:52 | history | became hot network question | |||
| May 17, 2023 at 13:37 | comment | added | Davislor | Welcome to the site. What would really be more helpful to us and you is if you write your own code to solve the actual problem you care about—you can tag it as beginner if you want—and ask our advice on that. | |
| May 17, 2023 at 3:15 | comment | added | Davislor | @J_H If you don’t need that much precision, changing the element type from double to float allows my code to auto-vectorize eight elements at once. It probably would not help the original much, since that version does not vectorize. (Better yet, reokace double everywhere with elem_t and set using elem_t = double;, so you can change it in one place and compare.) | |
| May 16, 2023 at 23:55 | answer | added | Davislor | timeline score: 10 | |
| May 16, 2023 at 23:23 | comment | added | J_H | You proposed that revised code might run in 6 nanoseconds. How many nanoseconds are consumed by the current code? Posting a relevant godbolt.org link would be helpful. You did not describe your use case, but I'm guessing that looping till we achieve accuracy of .01 ångström won't make a practical difference for most traveling salesman problems. You use doubles. Rather than making a million calls, you probably want to take Davislor's hint and accept a vector of a million (lat,lng) single-floats. I do hope you're not performing 10^12 all-pairs distance calculations.... | |
| May 16, 2023 at 17:44 | comment | added | Mast♦ | Do you understand why the code was written the way it is or just find it on the internet? | |
| May 16, 2023 at 17:15 | comment | added | Davislor | Also, why do you import pybind11? You don’t seem to ever use it. | |
| May 16, 2023 at 17:14 | comment | added | Davislor | Do you have the option of changing the API to take and return structures of arrays, so that you could use SIMD? | |
| May 16, 2023 at 16:17 | review | Close votes | |||
| May 17, 2023 at 17:34 | |||||
| S May 16, 2023 at 15:52 | review | First questions | |||
| May 16, 2023 at 16:03 | |||||
| S May 16, 2023 at 15:52 | history | asked | Pierre Levoisin | CC BY-SA 4.0 |