Talk:Scientific notation
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[edit] Standard index notation
The name I've always been taught is something like 'standard index notation'.
- If you don't remember what it was then the teaching must have been rather ineffective. Are you sure it wasn't "index standard anecdotal notation"?
'Scientific notation' seems a bit vague - aren't there many other scientific notations?
- It is a fairly commonly understood phrase. Yes there are many other scientific notations, but are there any that could be referred to without qualification? – Smyth 15:34, 9 Oct 2004 (UTC)
[edit] suggested paragraph
Should the following paragraph (or parts of) from Floating point be put on this page?
- In other words, we could represent a number a by two numbers m and e, such that a = m × be. In any such system we pick a base b (called the base of numeration, also radix) and a precision p (how many digits to store). m (which is called the mantissa, also significand) is a p digit number of the form +-d.ddd...ddd (each digit being an integer between 0 and b-1 inclusive). If the leading digit of m is non-zero then the number is said to be normalised.
[edit] breaking quantities
If we follow a convention of writing 1.2E31 instead we can avoid the problem of having a break in the quanity...1.2 x
1031 Pizza Puzzle
- You can force quantities to break as one word with the "non-breaking space" ( ): 1.2 × 1031. Besides, 1.2E31 is very ugly "calculator notation". I nearly cried when I saw someone use it on his math test paper. – Boudewijn 1 July 2005 12:12 (UTC)
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- 1.2E31 is incorrect, as stated on this page. Fresheneesz 04:13, 15 September 2006 (UTC)
[edit] Cleaning Up
What needs cleaning up about this article? Lochok 04:03, 14 November 2005 (UTC)
- It's not as bad as when the request was orginally made, but there are still a proliferation of one sentence paragraphs and I usually find a couple typos or redundancies everytime I look at it. It is much better now. The label can probably go soon. Jmeppley 22:21, 14 November 2005 (UTC)
[edit] parenthesis notation
Should also explain parenthesis notation indicating error, e.g., "1.345(67)".
[edit] Fortran
In Fortran, I recall that their exponential notation sometimes uses a 'd' instead of 'e'. For example, a number might be written as 1.234d-4 meaning the same thing as 1.234 * 10^-4 . I could have been incorrectly informed, but I think this would be a nice note on this page if someone can find a source for it (I looked quickly, but didn't find anything). Fresheneesz 04:10, 15 September 2006 (UTC)
- From the Nastran 77 Standard (http://www.fortran.com/F77_std/rjcnf-4.html#sh-4.5)
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- 4.5.1 Double Precision Exponent.
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- The form of a double precision exponent is the letter D followed by an optionally signed integer constant. A double precision exponent denotes a power of ten. Note that the form and interpretation of a double precision exponent are identical to those of a real exponent, except that the letter D is used instead of the letter E.
- Nastran uses the letter D to denote double precision instead of the single precision (or float) data type. Thus, this is an artifact of Nastran syntax. Jebix
[edit] Normalised form
Re the 3rd paragraph - i believe it should read as follows:
- In normalized form, b is chosen such that
rather than "a is chosen". Given a number we wish to represent in normalised form, the |a| value is determined (mod a power of 10) - there is nothing to choose. We choose b so that a has the desired magnitude, not the other way round.
I changed this yesterday, but it was reverted by 75.35.109.215 with no comment. Before I put it back, would any one like to comment? JoeKearney 21:17, 18 January 2007 (UTC)
Since there has been noting said here for ten days I've changed it back. Please discuss here if you think it's wrong rather than just re-editing it. JoeKearney 01:09, 29 January 2007 (UTC)
[edit] Standard form?
I thought that was the entire number, ie-
6,765
instead of
6.765*10^3
DarkestMoonlight (talk) 16:15, 17 March 2008 (UTC)
- Sorry, you thought wrong, for example: http://www.gcse.com/maths/standard_form.htm - 81.138.169.201 (talk) 15:49, 7 April 2008 (UTC)
In this same section, the exponents are not showing in my ie browser (but I don't know how to fix this on the page. can someone else? 5.72×10^9 shows up as 5.72×10 −6.1×10^−9 shows up as −6.1×10 —Preceding unsigned comment added by Mjvais (talk • contribs) 15:24, 22 April 2008 (UTC)
[edit] Isn't that backwards?
(Normalized) scientific notation is often called exponential notation...
AFAIK, "exponential notation" is generic, while "scientific notation" specifically refers to the one normalized so that the mantissa is in [1, 10), and "engineering notation" to the one normalized so that the mantissa is in [1, 1000) and the exponent is an integer multiple of three. Is that correct? --Army1987 (talk) 13:02, 9 June 2008 (UTC)