5

The radix point is the decimal separator character.

A third of the world uses a ,, another third use a . and the remaining do not seem to care... And then you have cases like Switzerland which use , for most numbers, and . when talking about money!

In all this we're trying to unify the input so want to something like

Please enter all numbers using a "." as the decimal separator

There will be non-technical people using this, and there will be people from around the world who are used to using , for their decimal separator.

a) Is there a better term for "decimal separator"?

b) Is there a better way to phrase the statement to make it clear what we're asking?

RemarkLima
  • 1,904
  • 2
    The term 'radix point' is the hypernym for all separators used to show where the whole number part of a number ends. Thus in 101.11 [base 2], = 5.75 as a decimal, the bicimal point is still a radix point. The base ten separator is known generally as a 'decimal separator' or 'decimal mark' (see Wikipedia); 'decimal point' is the most common term at least in the UK, but here commas are not used as separators. // You seem to be asking about a term readily understandable worldwide, but ELU only deals with English language usages. Perhaps Maths SE would be a better place to ask. – Edwin Ashworth Jul 15 '17 at 06:31
  • I'm voting to close this question as off-topic because it belongs on https://math.stackexchange.com/ –  Jul 15 '17 at 06:34
  • 1
    FWIW, "decimal separator" is clear to me as a native AmE speaker—but then, as a native AmE speaker it probably wouldn't occur to me to use anything other than a ".". You could consider including an example if that fits into the parameters of your project. – 1006a Jul 15 '17 at 06:34
  • 7
    @Josh I respectfully disagree, the question isn't about the "radix point" or any mathematic notations, but how to communicate to "a man in the street" what I mean then I say "decimal separator". i.e. how do I communicate the character which goes between the dollars and cents / pounds and pence / euros and cents? Otherwise you'll be saying that "Should I say aircraft, airplane, or aeroplane?" belongs on aviation! – RemarkLima Jul 15 '17 at 06:59
  • @EdwinAshworth but I'm not asking about what the Radix point is, simply how best to communicate that the marking, either "," or "." should be a "." - for me, this really is English language and I'm certain it would get closed as off topic on Maths because it's about language. I think 1006a may have it and just include examples. – RemarkLima Jul 15 '17 at 07:02
  • The more common definition for that "character " is "decimal point" as evidence shows. How that would be internationally understood is a different matter. The inclusion of exemples etc. is still another issue. –  Jul 15 '17 at 07:18
  • Does question b) not ask that? I.e. You could make it clearer with examples? And "no" is a valid answer too right? – RemarkLima Jul 15 '17 at 07:24
  • But I was clearing up a possible source of confusion the question might introduce (for other readers if not yourself) by mentioning the accepted definition of 'radix point', not answering your subsequent question. // 'Please enter all numbers using a "." as the decimal separator' seems fine for Anglophones, but how can 'non-technical people' who also don't speak English understand this? – Edwin Ashworth Jul 15 '17 at 08:50
  • I don't think you'll find a better alternative to decimal separator. However, the correct solution is to let users enter their input using their own locale settings, and have the system deal with it appropriately. – michael.hor257k Jul 15 '17 at 09:00
  • Thanks Edwin, good of the clarification. @michael.hor257k - it was in an answer that has been deleted, but the essence is that the business (inc. German, France and Italian colleagues) have agreed that everyone will use US / UK notation. The trouble is, so many inputs are US / UK centric that many of the people are already used to inputting data that way so we're getting a lot of random result with some people using local formats and other (in the same locale) using US / UK notation. So, to simplify the whole process it's to pick a universal one - there will still be errors but maybe fewer. – RemarkLima Jul 15 '17 at 09:18
  • @RemarkLima In my experience, it's easy to pick a universal format but not at all easy to get users to conform to it. In the end, it's easier to bend the system than people. – michael.hor257k Jul 15 '17 at 09:32
  • @michael.hor257k it was doing exactly that, but out of my hands now... It may go back, but either way we're going to get a lot of input errors... – RemarkLima Jul 15 '17 at 11:32
  • 1
    @Josh DEFINITELY not about math. Perhaps UX SE instead. RemarkLima, perhaps display the radix but only allow users to type digits? Relying on people following an instruction like that is only kicking the ball down the road. – Spencer Jul 29 '17 at 11:55
  • @RemarkLima What is the meaning of the number? Is it amount, currency, body height, or what? If you are more concrete, maybe we may find not the Very General Term, but a suitable solution of your specific issue. – Honza Zidek Aug 01 '17 at 09:06

1 Answers1

5

Based also on your further comments I interpret your question as primarily "how to specify the decimal separator so all users clearly understand", my answer is rather practical than linguistic :)

Is there a better term for "decimal separator"?

I don't think so.

Is there a better way to phrase the statement to make it clear what we're asking?

Sure, here you have so many possibilities! It depends on the meaning of the number. You may also include a few examples to make it really clear.

E.g.:

  • Enter your height in meters, use "." as decimal separator, e.g. 1m 72cm as "1.72"
  • Enter the price you request, use "." as decimal separator, e.g. 15€ 50cents as "15.50"
Honza Zidek
  • 4,025
  • 1
    +1 for "decimal separator" being the best term. Ngrams show it's far more common than decimal comma, decimal mark or decimal period, though unsurprisingly dwarfed by decimal point. – AndyT Aug 01 '17 at 10:06
  • 1
    Good use of examples, and thank you for inferring that the question is about being understood - the whole point of languages right! – RemarkLima Aug 02 '17 at 07:04