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Talk:Continuous or discrete variable

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This is an old revision of this page, as edited by GodMadeTheIntegers (talk | contribs) at 15:52, 30 April 2015 (a flawed and clumsy definition). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

a flawed and clumsy definition

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In mathematics, variables are either continuous or discrete, depending on whether or not there are gaps between a value that the variable could take on and any other permitted values.

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Really? If a variable can assume any value except 0, then that's a gap. Does that make it discrete? Michael Hardy (talk) 14:52, 30 April 2015 (UTC)[reply]

. . . and notice the two alternatives:
  • "whether"
  • "or not".
Which corresponds to "continuous" and which to "discrete"? If the reader thinks there's a tacit "respectively" then the first would be "continuous" since "continuous" was named before "discrete" in the opening sentence. Michael Hardy (talk) 15:12, 30 April 2015 (UTC)[reply]
The article later has "the number of permitted values is either finite or countably infinite" for discrete. That seems more rigorous. Common objection is, typical motivating examples of continuous variables are time and other physical measurements. Common reply is, we can usefully model them as uncountable, without claiming the model is literally true to actual infinity. --GodMadeTheIntegers (talk) 15:52, 30 April 2015 (UTC)[reply]