Using the LINEST function in Microsoft Excel

    The Microsoft Excel LINEST function is very useful when finding the Polynomial formula y = b + m1x + m2x^2 + m3x^3 + m4x^4 for a curve but the help information in Excel is a little difficult to understand. This description should make it a bit easier.

This function will only work in some versions of Microsoft Office if the appropriate Add-in has been installed. This can be verified by checking in the Excel toolbar:- Tools, Add-Ins, Analysis ToolPak.

 Two columns of data are made containing the known X and Y coordinates of the curve. An example of this can be found at lin-spreadsheet-01.xls where the X and Y columns represent the Signal Generator Output ( Volts) and the DMM Reading ( Volts) of a non linear detector circuit respectively.

To demonstrate the use of the LINEST function copy the whole table(A1:A13,B1:B13) into a new spreadsheet.

Highlight the five cells (B17:F17) that are to contain the results and press F2 to select all five cells.

Enter the formula "=LINEST(A2:A13,B2:B13^{1,2,3,4})" 

Press the CTRL + SHIFT + ENTER keys all together and the final calculation will be made.

An alternative method is given for the LOGEST function at Logest Function

 

  Return to Understanding Coaxial RF Transmission Lines by Measurement and Calculation part2

 

This information is provided by Chemandy Electronics in order to promote the FLEXI-BOX