The diagrams below show how our site separates degrees into cardinal directions. There are sixteen cardinal direction names. That corresponds to 22.5° for each section of the circle (360°). The actual division between the sixteen cardinal directions falls to decimal places.
Our site uses slightly different techniques when it comes to determining what the cardinal direction is depending on whether only a whole number is known or whether at least one decimal place is known.
Most degrees received into this system are only known to a whole number. In order to use the exact mathematical separation for the sixteen cardinal directions you must know the actual decimal place. Since this is not known in this circumstance an alternative has been devised for this system that is not based on any published scientific method. In the diagrams below you will notice that for values that are on the border between two cardinal directions this system will report both cardinal directions. The word "between" or a slash (/) will exist between the two cardinal directions in this circumstance. The difference between the two diagrams below occurs depending on if there is a known decimal place for the degrees.
Lets use the example of the border between N and NNE which occurs mathematically at 11.25°. If the system receives a value of 11 degrees, just a whole number, we don't know what the original number might have been. That number could have been rounded up or down or may not have even been known to any precision beyond the whole number. The important thing to note is that the value could be anywhere from 10.51° to 11.49° and we would not know. Within that range falls the mathematical division between N and NNE. In this circumstance we treat 11 degrees as being between N and NNE rather than specifying which cardinal direction it actually is because we don't know it to be any closer to one than the other.
In some cases the degrees are known beyond a whole number. For example, distance calculations are calculated by our site and we do know the decimal places of the degrees. In this circumstance our site uses the mathematical separation to get the cardinal direction and will only report two cardinal directions if the value falls on the exact mathematical separation between the two cardinal directions. 11.24° would be reported as N, 11.25° would be reported as between N and NNE, and 11.26° would be reported as NNE. It is important to point out however that just because we get decimal places doesn't mean the degrees are precise to some or any of the decimal places. For this reason it would probably be best if our site reported between N and NNE for within a small range above and below 11.25° in this circumstance. However, since there is no precedent that I know of to do that this site will for now continue doing it the way we have mentioned for when the number is a whole number and for when there are decimal places known.
The procedure for calculating the cardinal direction in this system near the separation of cardinal directions is subject to being adjusted slightly in the future.
