Take the 2-minute tour ×
English Language & Usage Stack Exchange is a question and answer site for linguists, etymologists, and serious English language enthusiasts. It's 100% free, no registration required.

I know there is a term for a number that is the power of 2, such as 8, 32, 128, 4096 -- but it slipped my mind.

share|improve this question
2  
Just for the record - is there a reason you skipped every other power of two in your example?!! –  Joe Blow Jul 11 '11 at 8:34
    
I see what you mean, but 4096 doesn't fit that pattern. It's just a random selection. –  The English Chicken Jul 11 '11 at 8:40
1  
Actually 4096 fits the pattern, because it's a power of 2. –  Alenanno Jul 11 '11 at 8:58
8  
I'd call them round numbers, but that may be a programmers affliction. ;) –  MSalters Jul 11 '11 at 10:16
1  
@Alenanno Just for what it's worth. Read my comment again. It says "In your example", the example being: "8, 32, 128, 4096". OK? –  Joe Blow Jul 11 '11 at 15:44

3 Answers 3

up vote 22 down vote accepted

A "power of two" seems like a good name.

Although 'exponent' has been suggested, it is not correct

The relationship is quite simple, though:

3 is the exponent which generates the power of two   8       (23 = 8)

12 is the exponent which generates the power of two 4096  (212 = 4096)

share|improve this answer
1  
Indeed. Any mathematical documentation I can find refers to them as powers of two. –  Vincent McNabb Jul 11 '11 at 9:00
5  
"It's more precise than saying an exponent." - No, "exponent" would simply be wrong here, not just less precise. Why did you even mention it? It just muddies the waters. I could understand it if Jen had suggested it, and you were making a correction - but you're just correcting yourself here. –  MT_Head Jul 12 '11 at 10:00
    
@MT_Head, I agree. What I typed yesterday was just fastest gun in the west syndrome. I could edit my answer, but it seems a little late now. –  pavium Jul 12 '11 at 11:33
    
@pavium - Feel free to edit your answer! Remember, the whole reputation-points thing is (supposed to be) secondary to giving correct answers, not just for the OP but for future Googlers. In this case, a straight edit would make your answer identical with @Digital Powers', but perhaps an explanatory note? Future Googlers might not read the comments. –  MT_Head Jul 12 '11 at 16:39

You simply call them "powers of two"; there is no other name.

share|improve this answer

In programming, especially graphics programming (textures), powers of two are sometimes referred to as POT, and non-powers of two as NPOT.

But obviously the word "pot" has strong connotations, and so this term can be used only in such a context unambiguously. Anywhere else, "power of two" is a much better choice.

share|improve this answer
    
Fascinating, @nikai, I have never heard that one. Can you see any examples of that online, just out of curiosity? Cheers –  Joe Blow Jul 12 '11 at 8:00
1  
Sure, here are two OpenGL specifications using it for texture dimensions: opengl.org/registry/specs/ARB/texture_non_power_of_two.txt opengl.org/registry/specs/NV/texture_rectangle.txt Here it is used in papers in context of ordering policy: or.journal.informs.org/cgi/content/abstract/58/2/492 ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=4737780 –  Nicolas Kaiser Jul 12 '11 at 9:20
    
FANTASTIC REFERENCE, Nikai! Awesome. @Jen, @Nikai has a great term, even though little arcane. I mentioned 3D graphics in my answer -- there's the term!! How awesome. Great stuff. –  Joe Blow Jul 12 '11 at 10:35

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.