The fourty five degree sort allows you to show the whole zodiac in a fourty five degree section.
You can view positions at the same degree in signs of the same mode as being equivalent because they are all square or opposed to each other: 10 Aries is square 10 Cancer, opposed to 10 Libra and square to 10 Capricorn. A planet at one of these points will be in some kind of hard aspect to a planet on any of the other points. This would be a ninety degree sort.
The fourty five degree sort folds the ninety degree sort in half to include the minor aspects of semi-square (45 degrees) and sesquiquadrate (135). Thinking about a planet at 10 degrees of the cardinal signs, as above, we can now say that they’re also in hard aspect to planets at 25 degrees of the fixed signs.
0 cardianal is 45 degrees from 15 fixed. 0 fixed is 45 degrees from 15 mutable. 0 mutable is 45 degrees away from 15 cardinal.
This is an eighth harmonic arrangement.