Hello, In the message bellow, you ask to join graphic mailing list. I don't know whether this is the place. If it is not, please excuse me.
Note that I am just a user, not a programmer. As a mechanical engineer, I sometimes use polynomial trendlines in professional domain (on MS XL...) One example : We have to deliver machines with calibration reports, including a "Pressure drop" vs "water flow rate" curve. I happends that the variation of "pressure drop" when you increase the "water flow rate" more or less follows a quadratic law (a parabolic curve) >From the measured values, we insert a polynomial curve (degree 2), and print it with the equation and the "R²" correlation factor. Concerning trend curves in Ooo calc : I did not see that it was possible to force the curve through the origin (0,0) i.e y=a'x in stead of y=ax+b Maybe I missed it. This would be an interesting feature. Concerning comparison with other spreadsheets, I appreciate very much the ergonomy of Gnumerics for graphics. It is different, original and easy to use. Gnumeric have polynomial trend curve, and "force the curve through origin" feature. The only thing is that you cannot do(?) is copy/paste the equation. Thank you again for bringing us great software. Best regards, Aveldro [EMAIL PROTECTED] _______________________________________________________________________________________ Sujet : [Issue 20819] add polynomial regression type De : [EMAIL PROTECTED] Date : 30 Nov 2008 09:59:41 -0000 Pour : [EMAIL PROTECTED] To comment on the following update, log in, then open the issue: http://www.openoffice.org/issues/show_bug.cgi?id=20819 ------- Additional comments from [EMAIL PROTECTED] Sun Nov 30 09:59:36 +0000 2008 ------- Hello, I am looking for help about user experience with polynomial regression curve. As said previously by Ingrid, we need file format modification prior been able to solve this issue. Please join graphics mailing list to discuss about what is needed. A first draft has been written for a file format change in ODF, in order to be able to add polynomial regression curve. It is obvious that asking a file format change only for polynomial regression curve is unproductive. That's why the proposition include other important issues for regression curve: - moving average trend line (issue 66819) - force intercept (issue 34093) - extrapolate (issue 5085) Do you see some other features that are missing to trend lines? I made the comparison with MS-Excel only, but other spreadsheets may have interesting features. We need argument to obtain file format modification. Since how long do other spreadsheets have polynomial trend lines? Which concrete applications do you have with polynomial trend line, not only in maths and physics? ... With this four first features, there are things that should be discussed before asking to OASIS TC a file format change: - polynomial trend line: exponential terms is an option, but is it necessary? - moving average trend line: by default it is prior moving average. What about adding central moving average? Is it necessary, or will there be too many parameters, most of them useless? Many thanks in advance for your answers on graphics mailing list.
