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In mathematics, the absolute value of a number n is either −n if n is negative or n itself if otherwise.

Is there a single word or shorter description for the replacement of n with its absolute value?

Andrew Leach
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stefan
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  • I think you would call it "modulus n" but writing |n| is shortest of all. Perhaps I've misunderstood the question. [Sorry, can't get an italic n inside vertical bars] – Andrew Leach Jul 22 '12 at 22:30
  • @AndrewLeach No, modulus is something else; it’s the remainder function, as in 7 mod 3 is 1 (because 3 goes into 7 twice with a remainder of 1), usually written 7 % 3 == 1 in C-derived programming languages. – tchrist Jul 22 '12 at 22:35
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    @tchrist I know that as modulo, not modulus. – Andrew Leach Jul 22 '12 at 22:37
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    @AndrewLeach I’ve only heard magnitude for abs(x), never modulus. I would just hate for a paired ‑us and a ‑o term to be that different, because it’s just a different case ending to, or a different/later evolution of, the same Latin word. For a good time, try to find programming languages that allow you to actually write abs(x) as |x|. – tchrist Jul 22 '12 at 22:41
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    RE modulo/modulus: My understanding is that in the expression x % y = z, e.g. 7 mod 3 = 1, y is the modulus, and we read the expression as "x modulo y equals z". – Jay Jul 23 '12 at 03:23
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    From Wikipedia, "In mathematics, the absolute value (or modulus) | a | of a real number a is the numerical value of a without regard to its sign. So, for example, the absolute value of 3 is 3, and the absolute value of –3 is also 3. The absolute value of a number may be thought of as its distance from zero." – coleopterist Jul 23 '12 at 06:58
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    I think modulus might be more common in complex analysis. That is where I remember using it in the way @AndrewLeach suggests. For complex numbers of the form z = a + 0i, the modulus of z equals the absolute value of a. – Daniel Harbour Jul 23 '12 at 12:07
  • 9 years later, for anyone who would like a mathematician's perspective, it is definitely the case that the absolute value of a number is sometimes referred to as its modulus, as @DanielHarbour says perhaps most often in the complex-analysis setting. (Bourbaki uses the even more confusing 'module'!) This probably inspired the term ’modular function’ (in the Haar-measure context). – LSpice Sep 24 '21 at 16:26

2 Answers2

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|n| is called taking its magnitude. That is the value without the sign, if you would.

KutuluMike
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tchrist
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    Your format does not fit the mobile version of EL&U; you should edit the following string that is shown on the screen: ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠ –  Jul 22 '12 at 23:06
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    Furthermore, as engineer, I do not ever hear "magnitude" to refer to abs(Z). –  Jul 22 '12 at 23:11
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    @Carlo_R. There is no string shown on the screen. I have no idea what you are talking about. If there are requirements about this smartypantys phone of yours that everyone is expected to follow, they should be built into the edit widget. And they aren’t. Try a real computer. – tchrist Jul 22 '12 at 23:54
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    Whatever happened to "Civility is required at all times"? – Ryogi Jul 23 '12 at 02:53
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It’s hard to say without having a context, but you might be able to use unsigned, as in Compute the absolute difference between unsigned integers using sse.

You can also just talk about ignoring the sign.

Community
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Daniel Harbour
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