[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: Re: [office-comment] ODFF: list of suggestions
May I add these suggestions to the list? B function * "this function returns the probability that the number of successful trials shall lie between S and S2." - should say clearly if inclusive or exclusive (inclusive I think). * Test cases: " =B(7;0.5;3) 0.24343750" - wrong result - 0.2734375 is correct, as returned by Calc, and checked from the actual formula by me. NEGBINOMDIST * The formula image could be improved - k is undefined, and unnecessary * This really needs to say "exactly number_f failures" * For consistency, could simply use eg "F" rather than "number_f" in parameters. Even better, use standard symbols x, r, p. GAUSS NORMSDIST (mentioned twice) should read LEGACY.NORMSDIST. Might be better to use NORMDIST for the definition instead. NORMSDIST " exactly NORMDIST(x)." - NORMDIST is not defined with only 1 parameter - should be "NORMDIST(x;0;1;TRUE())". LOGNORMDIST *Syntax: "NORMDIST " should read "LOGNORMDIST" *Formulae: - I suspect that the integral may need to be from -infinity not 0 for the cumulative dist function (as with NORMDIST). I can't find this formula on the net - normally it seems to be quoted as 1/2+1/2*ERF((LN(x)-u)/(s*SQRT(2))) - which does seem to produce the same results, and may be preferable if it is standard practice. Or could be defined in terms of NORMDIST or NORMSDIST which is the simplest. FV The first link to PV is dead FDIST Is it worth mentioning that as well as Calc, Gnumeric and KSpread, Excel (Excel97 at least) also seems to calculate the right tail? PROB *This needs to specify if Data must be ordered or not (unordered?). *It would also be better to be clear about whether Data must be sequential (is 1, 2, 3, 5 (missing 4) OK?) and/or integer (is 1, 2.5, 3, 4 OK?). *It would also be better to be clear about whether Start and End need to exist within Data (no?) and also whether they can be higher/lower than the max/min values in Data (yes?) * It would also be better to be clear about whether Start can be higher than End. Although they're defined as lower/upper bounds, is 'Start>End' an error, or valid with a probability of 0 returned? * This needs to specify how the result is calculated if End is omitted and Start is not present in Data (Calc returns 0). * This needs to specify the type of error returned - eg #N/A if Data, Probability are different lengths. This is important because #N/A is a specific (testable) type of error. "Array Functions" This categorisation seems to me to be inconsistent. Functions which return arrays are: MINVERSE, MMULT, MUNIT, TRANSPOSE, FREQUENCY, GROWTH, LINEST, LOGEST, TREND Functions which have ForceArray parameters are: MDETERM, MINVERSE, MMULT, SUMPRODUCT, SUMX2MY2, SUMX2PY2, SUMXMY2, CORREL, COVAR, FORECAST, FTEST, INTERCEPT, MODE, PEARSON, PROB, RSQ, SLOPE, STEYX, TTEST (and LOOKUP sometimes). This doesn't relate to the current functions listed as array functions. We have for instance SUMPRODUCT listed as an array function (but it's really a maths function) but MODE listed in stats (OK) - but both force array_mode calculation. Surely either both should be 'array functions' or both where they belong. Perhaps only matrix functions should be in this category: MINVERSE, MMULT, MUNIT, TRANSPOSE, MDETERM. It could then be called 'matrix functions'. David In harmony David
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]