I have reviewed Why is law of cosines more preferable than haversine when calculating distance between two latitude-longitude points? and that does not equate to the specific question that I wish to ask because I'm looking for a simple answer about accuracy of multiple formulas. While there is an answer there that discusses accuracy, it does it more as a comparison between two methods and depends on the reader understanding trigonometry to follow the answer. I'm looking, mostly, for simple margins of error.
This is my first time trying to compute distance from two points on the ground. I've been researching this and see that a lot of people use the Haversine Formula, but I also see comments, whenever I read about it, that there are accuracy issues. Apparently, from what I see, Vincenty is more accurate, but I've also seen comments that the Law of Cosines is better.
What I don't see is any way to find out just how inaccurate I can expect a method to be. Apparently there can be problems at extremely small distances in Haversine, but I'm not clear on that.
I'd like to just go on and use GeoPy in my program. I'm basically working with distances of 100 miles or less. Most of the time I'm comparing coordinates of two locations to see if they're close enough to be considered the same address. If the accuracy is going to be within a few feet, that's close enough.
Can someone either point to a good resource or explain what kind of accuracy I can expect from the different methods I've mentioned and if there's a way to know what the conditions are that will give me more or less accurate answers?
I do see that GeoPy has a feature to tell me the confidence of a calculation, but I need to be able to know, in general, what kind of accuracy I can get from any one method overall, not for each individual calculation.
I see a lot about one method being better than another, but I don't see much on what kind of accuracy I can expect from any one method and what factors I can look at to tell me how accurate that method is. That's what I'd like help finding.