Bug 123192 - Improve help for function ATAN2
Improve help for function ATAN2
 Status: RESOLVED FIXED None LibreOffice Unclassified Documentation (show other bugs) 6.3.0.0.alpha0+ x86-64 (AMD64) Windows (All) medium enhancement Mark target:6.3.0 easyHack HelpGaps-NewFeatures Show dependency tree / graph

 Reported: 2019-02-05 15:13 UTC by Regina Henschel 2019-03-28 14:50 UTC (History) 4 users (show) himajin100000 mentoring olivier.hallot xiscofauli

Attachments
Illustration as svg (12.18 KB, image/svg+xml)
2019-02-13 20:42 UTC, Regina Henschel
Details
source of Illustration (13.22 KB, application/vnd.oasis.opendocument.graphics)
2019-02-13 20:48 UTC, Regina Henschel
Details

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 Regina Henschel 2019-02-05 15:13:04 UTC ```The ATAN2 function in Calc has the syntax ATAN2(NumberX; NumberY) Unfortunately that is the opposite order of arguments as usual in programming language, e.g. Python, JavaScript, C++. So there should be a warning about this fact. It could be something like this, "Programming languages have usually the opposite order of arguments for their atan2 function." In this light, the given example is badly chosen, because both parameters have the same value 20 in the example. And using a point from the first quadrant, masks the advantage over using ATAN(NumberY/NumberX). The example should use a point from the second quadrant, e.g. point(-5|9). The help says "Returns the inverse trigonometric tangent of the specified x and y coordinates.". That makes no mathematical sense, remove it. Suggestion: "ATAN2 returns the angle (in radians) between the x-axis and a line from the origin to the point (NumberX|NumberY)". The text "To return the angle in degrees, use the DEGREES function." is misleading, because it sounds as if DEGREES would be a similar function as ATAN2, only that the result is in degrees. The example has it correct. It should be something like this, "To get the angle in degrees apply the DEGREES function to the result." The spec has the text, "ATAN2(0;0) is implementation-defined, evaluators may return 0 or an Error.". The help is missing, what LibreOffice does. In fact, LibreOffice results 0 for ATAN2(0;0). But Excel 365 results error #DIV/0! for ATAN2(0;0). Therefore it should be mentioned. The help should mention, that the function can be used in converting cartesian coordinates to polar coordinates. An illustration would be helpful.``` Olivier Hallot 2019-02-05 17:25:49 UTC ```Set to New. Target help page: https://help.libreoffice.org/6.3/en-US/text/scalc/01/04060106.html?DbPAR=CALC#bm_id3153983``` Regina Henschel 2019-02-13 20:42:17 UTC ```Created attachment 149281 [details] Illustration as svg``` Regina Henschel 2019-02-13 20:48:43 UTC ```Created attachment 149282 [details] source of Illustration Hi Mark, that is my version of an illustration. You might want to alter it or make your own one. Please do not use LibreOffice to generate an svg-image. Since LibreOffice has changed the svg export for the benefit of Impress, it generates horrible svg source in case of Draw. You get much cleaner svg source if you use Apache OpenOffice which still has the old svg export for Draw.``` Commit Notification 2019-02-25 16:30:15 UTC ```Mark committed a patch related to this issue. It has been pushed to "master": https://git.libreoffice.org/help/+/3efabd3e5e7ac30a81de5f286f6c9c5a3327effb%5E%21 tdf#123192 - Improve help for function ATAN2``` Xisco Faulí 2019-03-28 04:17:53 UTC `A polite ping, still working on this bug?`