Quadratic linear fit

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<p>I have a vey quick (and hopefully easy question). When I use a quadratic fit in Empower and then try to create the same best fit line in Excel I don't get the same equation for that line, or even anything close really.</p><p></p><p>If I use my calculator, Maple, or calculate the equation of the best fit line manually, I get the equation given to me by Empower.</p><p></p><p>So … anyone know why Excel falls short here? What is going on? What is the different approach that Excel is using?</p><p></p><p>I'm trying to move a satellite lab past the point of using Excel to calculate their results for them and start to have all this stuff done in Empower. However, we are going to run into problems if there is a disagreement between the Excel calculated and Empower calculated values. </p><p></p><p>TIA...</p>

Answers

  • Well, Quadratic and linear fits are very different. Are you choosing the same fit type in Maple, Excel and Empower? You can use a quadratic fit in Excel or Linear fit, depending on how you'd expect the data to shape out. Can you capture the equations *just* as you're doing them now, and maybe if I see what you're getting as results, I may be able to steer you in the right direction.

  • Thank you for your reply.

    I am using the same fit type in both Excel and Empower. The company for which I am working does not own Maple; however I personally do. When the same data points are entered into Maple, I obtain the exact same fit as given by Empower.

    I am a little unclear on what other additional information you are requesting. It truly looks like Excel is "in the wrong here". At this point, I am curious as to why so that we are aware of this and this same error can potentially be avoided in the future.

    Edit:

    I forgot, I started a thread here: http://www.chromforum.org/viewtopic.php?f=4&t=24567

    I believe you will see the information you requested in that thread.