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2012-02-21 16:30:07 +0200 respondió a una pregunta Is there a polynomial curve fit function(s) in Calc ?

As noted by others, this answer is now outdated. There is now a polynomial curve fitting function built into the LibreOffice chart/graphing facility.

CorelPolyGUI is an extension for LibreOffice that implements polynomial curve fits.

You can find it here: http://extensions.libreoffice.org/ext...

You can also use the linest function. LibreOffice doesn't automatically generate the values for x^2, x^3, etc when you use the linest function for polynomial regressions. You have to generate those values yourself in columns adjacent to the values for x, then run the regression across the set of cells that includes those values for different orders of x and the values for y.

The instructions from http://help.libreoffice.org/Chart/Tre...

A polynomial regression curve cannot be added [to a chart] automatically. You must calculate this curve manually.

Create a table with the columns x, x², x³, … , xⁿ, y up to the desired degree n.

Use the formula =LINEST(Data_Y,Data_X) with the complete range x to xⁿ (without headings) as Data_X.

The first row of the LINEST output contains the coefficients of the regression polynomial, with the coefficient of xⁿ at the leftmost position.

The first element of the third row of the LINEST output is the value of r². See the LINEST function for details on proper use and an explanation of the other output parameters.

Also, see the manual for linest at http://help.libreoffice.org/3.4/Calc/...

Note that using linest with an array requires that the user exit the cell containing the linest function with Ctrl+Shift+Enter, not just pressing Enter.