<html> <head> <base href="https://bugs.documentfoundation.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - LibreOffice Calc power regression coefficients error" href="https://bugs.documentfoundation.org/show_bug.cgi?id=142643#c15">Comment # 15</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - LibreOffice Calc power regression coefficients error" href="https://bugs.documentfoundation.org/show_bug.cgi?id=142643">bug 142643</a> from <a class="email" href="mailto:uwe@franke-auer.de" title="Uwe Auer <uwe@franke-auer.de>"> Uwe Auer</a> <pre>Created <a href="https://bugs.documentfoundation.org/attachment.cgi?id=172638" name="attach_172638" title="Power Regresssion Methods - Comparision of Coefficients">attachment 172638</a> <a href="https://bugs.documentfoundation.org/attachment.cgi?id=172638&action=edit" title="Power Regresssion Methods - Comparision of Coefficients">[details]</a> Power Regresssion Methods - Comparision of Coefficients I'm not sure whether this is really a pure documentation issue only, but indeed a problem of the "Data -> Statistics -> Regression -> Type: Power Regression" functionality (at least from a users perspective). My comments are based on how I do such power regression, which essentially is based on using: [1] =SLOPE(LN(range_of_Y_values);LN(range_of_X_values)) [2] =EXP(INTERCEPT(LN(range_of_Y_values);LN(range_of_X_values))) according to function LN(f(x)) = LN(a) + b * LN(x) (derived from f(x)=ax^b) As a user I'd expect a "Power" regression analysis to yield the coefficients a and b directly (i.e. without any further exponentiation) just like a power trend line in a chart shows both coefficients correctly (without applying any further math) setting option "[x] Show Equation". So it least when comparing [1] Coefficients in trend line equation in chart --with-- [2] Coefficients in "Data -> Statistics -> Regression -> Type: Power Regression" (see cells J20 and J21 in the sample file) there is a discrepancy. See also attachment.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>