# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

**Re: Lunars using Bennett**

**From:**Alexandre Eremenko

**Date:**2008 Apr 4, 10:00 -0400

Dear Peter, > Firstly; these are not 'errors', > which implies inaccuracy, but rather > a limitation in precision. "Error" is a standard term in statistics. For example, "rounding error". Unlike in real life, in statistics this word has no negative flavor:-) > will NOT tend to accumulate, > but will tend to cancel each other out, They will do both things: cancel but still accumulate. More precisely, suppose that one application of some table introduces a random error x. Then n applications of this table can be expected to introduce an error of x times sqrt(n). So, if in some calculation, you use a table where precise numbers are rounded to 1', and you have to enter this table 4 times, then each entry has expected error 0'5, while the whole calculation 0'5 sqrt(4)=1'. If you have to use the table 9 times then the expected error of the whole will be 1'5 and so on. Alex. --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To unsubscribe, email NavList-unsubscribe@fer3.com -~----------~----~----~----~------~----~------~--~---