On 4/29/14 12:30 PM, Chris Angelico wrote:
On Tue, Apr 29, 2014 at 11:38 PM, Roy Smith <[email protected]> wrote:I'm trying to intuit, from the values I've been given, which coordinates are likely to be accurate to within a few miles. I'm willing to accept a few false negatives. If the number is float("38"), I'm willing to accept that it might actually be float("38.0000"), and I might be throwing out a good data point that I don't need to.You have one chance in ten, repeatably, of losing a digit. That is, roughly 10% of your four-decimal figures will appear to be three-decimal, and 1% of them will appear to be two-decimal, and so on. Is that "a few" false negatives? It feels like a lot IMO. But then, there's no alternative - the information's already gone.
Reminds me of the story that the first survey of Mt. Everest resulted in a height of exactly 29,000 feet, but to avoid the appearance of an estimate, they reported it as 29,002: http://www.jstor.org/stable/2684102
-- Ned Batchelder, http://nedbatchelder.com -- https://mail.python.org/mailman/listinfo/python-list
