# One word that means both radial AND annular

Radial lines divide a circle into pizza slices

Annular lines divide it up to make a bullseye shape

What if you do both, as in polar coordinates? Is there a word that means radial and annular?

Context of the sentence: "Pictures were divided into radial/annular slices"

• Whichever phrasing one may coin, it fails to convey the meaning adequately and immediately. "Radial sections of annual parts" seems a possible option to me.
– Kris
Commented Oct 3, 2018 at 9:49
• You're likely to get a better answer on a math board, since this is fairly domain specific. Commented Oct 3, 2018 at 12:01
• "Each picture was divided into a polar grid" or "The pictures were aligned to a polar grid" sound clear to me. Commented Oct 3, 2018 at 14:13
• As per this Mathematics SE question, these are called annular sectors. Commented Oct 7, 2018 at 19:36
• And annular sector patches refer to the areas defined by the grid. Commented Oct 8, 2018 at 3:19

If your application is in image processing, you can refer to this as Nipkow scanning, a technique based on the 1884 Nipkow disk, which was the dominant technology in the early days of television.. Electronic “line-by-line” scanning did not come into use until the 1930’s.

Another possibility is radar grid, based on the Plan Position Indicator that we’re all familiar with (at least from movies and TV). This is also a scanning technology, but different in concept from Nipkow scanning, since radar involves sending out a beam of radio waves and measuring the reflections. Nipkow scanning is more like photography, where some of the the light incident on a scene from all directions is reflected towards the camera. The camera is a passive recorder as opposed to an active illuminator.

Of course, your application may lie in a different area where neither television nor radar provide good analogies. The best adjective might simply be the the geometric shape, since terms like grid, mesh, scanning, discretization and the like will carry the meaning of division into small areas.

• I like this answer for providing different analogies than polar grid, and for educating about something cool, but as noted above with the link to the Math SE annular seems like the correct word Commented Oct 11, 2018 at 12:02

You might consider using the adjective "concentric". The figure diagram in your question can be referred to as a "concentric grid". You can offer details of its construction to fit your purpose.

Example 1: Instructions: Draw a concentric pattern of lines on the disk to establish a grid.

Example 2: A single word that describes the lines in your drawing is "concentric".

https://www.thefreedictionary.com/concentric

• Concentric refers to the circles but not the radial lines so I don't think this is the right word Commented Oct 4, 2018 at 7:54
• @SBoother - No. Any objects, lines, or shapes that share the same center are concentric. Some definitions don't mention this, others do. If they share a common point they are also concentric. In this case, they are concentric radii emanating from the center of the circle. Commented Oct 4, 2018 at 8:14
• Specifically - concentric means having a common center - "same-centered". Commented Oct 4, 2018 at 8:22
• Ok, then the sentence would be: "pictures were divided into concentric slices", which is then not true since they do not share a common center. The adjective is meant to apply to the slices/sections, not the lines Commented Oct 4, 2018 at 10:09
• Yes, that sentence would certainly work, but I would change the word "slices" to "sectors" (unless it is a pizza of course). Commented Oct 4, 2018 at 10:14