Hi :) Regina, this is not a criticism of you but just some of my anger at the world that gave me a fairly decent education in sciences and maths and made me practically unemployable as a result.
Ok, again -3 x -3 = 9 I think people tend to expect the - to make the result -9. Perhaps they expect the result to be the same as -(3^2) which is a completely different thing. Again this is more about people lack of maths understanding than about spreadsheets. An evening course or on-line course about maths is the answer, not documentation for a spreadsheet program. In the bug-report the first comment complains that spreadsheet programs stick to internationally agreed maths standard for the order in which to apply functions, Bodmas (stands for "Brackets, of/division, multiplication, add, subtract"). Choosing a non-standards order makes higher functions exponentially difficult or even impossible. Before the 0 was borrowed from Arabic notation simple multiplication and division was only possible by people with a university degree level of maths skills. Choosing to go against Bodmas would be similarly catastrophic. Business users like to left align numbers which makes simple addition more difficult at a glance, for example £34 £300 ====== £640 ?!!? Maths people and accountants tend to shudder at left aligned numbers, or realise they are likely to make a lot of cash from these people. A right-justified list makes it much more obvious £34 £300 ===== £334 in a much more obvious way. Ok, its a stupid example with only 2 numbers in the list but imagine with a LOT more numbers in the list, say 20 to 30 per page. Back to the expected result of -9. What is the square root? -3 x 3 is not really right. In fact we are now getting towards 2 dimensional numbers such as "imaginary numbers" and perhaps even getting close to chaos theory and fractal dimensions. In the bug-report the first post shows a stunning lack of understanding about maths, roughly along the lines of demanding that the spreadsheet program should give £640 in my example of adding numbers. " I definitly see this as a bug and confirm it. Here's what I did: 1: Input "=-3^2+4" into a spreadsheet cell, result is 13 2: Input "=4-3^2" into another cell, result is -5 3: Input "=-(3^2)+4" into a third cell, result is -5 The problem here seems to be that the program attaches the negative sign to the 3 in step one before doing the square, which it should not, unless manipulated by parentheses like this: "(-3)^2". " In 1 the result is 13 because the first function done is -3 x -3 = 9, and then add the 4 to give 13 In 2 the result is due to an ambiguity that is normally resolved by using the standards method of afaik 3 x 3 = 9, and then 4 - 9 = -5 People with maths skills generally realise there is a potential problem with the ambiguity here and might try fixing it by using brackets eg = 4 + (-3^2) which gives us 13 'obviously' since the inside of the bracket is done before applying the stuff outside the brackets. In 3 the result is -5 because the bracketed stuff is done first giving us +9 again, then outside the bracket that is made -+9 = -9 and then the 4 is added as expected. This is maths, not spreadsheet stuff, unless i made a mistake in how #2 should be treated according to the Bodmas standards (in which case the bug-report needs to be fixed asap) but afaik i'm right. Even if i am wrong this is not really a job for documentation except as a brief note that 'common-sense' sometimes over-rides Bodmas but will hopefully be fixed soon. Regards from Tom :) ________________________________ From: Regina Henschel <[email protected]> To: [email protected] Sent: Fri, 10 June, 2011 23:39:01 Subject: Re: [libreoffice-documentation] Re: Collecting small things in the Wiki Hi Tom, Tom Davies schrieb: > Hi :) > 3^2 does =9 ? That's not the problem. But -3^2 result in 9 and that is the problem. http://openoffice.org/bugzilla/show_bug.cgi?id=26755 Kind regards Regina -- Unsubscribe instructions: E-mail to [email protected] Posting guidelines + more: http://wiki.documentfoundation.org/Netiquette List archive: http://listarchives.libreoffice.org/global/documentation/ All messages sent to this list will be publicly archived and cannot be deleted -- Unsubscribe instructions: E-mail to [email protected] Posting guidelines + more: http://wiki.documentfoundation.org/Netiquette List archive: http://listarchives.libreoffice.org/global/documentation/ All messages sent to this list will be publicly archived and cannot be deleted
