Polynomial fits not working in Colorimeter-v05



  • @Will-Dickson ... we had a discussion about this in the "Additional tests for colorimeter..." thread and I think I was able to get polynomial fits to work in May-June of 2017 after you packaged v05. But now @maddiehankard and our group at St Thomas have created another pH curve that we are playing with and v05 will only let us use a linear fit (not even a second or third order polynomial... and we need 4th order). Our x-y data are below.

    # 2018-04-11 Hankard, Wolf, University of St.Thomas 
    # Colorimeter Data
    # LED white
    # -----------------------------
    # pH | Absorbance
    4.74  0.26
    5.45  0.21
    5.69  0.22
    6.36  0.25
    7.00  0.34
    7.43  0.44
    8.16  0.55
    9.17  0.62
    


  • @fisherba Thanks - I will have look this weekend.



  • @Will-Dickson Oh, silly us! The curve makes a u-shape, so we needed to drop the pH 4.74 value. Now the polynomial fitting works.



  • @fisherba

    Yes, I think that would be the issue. I'm glad you were able to get everything working.


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