Linearizing a Relation: How to Create a Best Fit Linear Line in Logger Pro

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ChanYoung Park
lq5ySf3.png

Hi! Above is a screenshot of logger pro that I'm currently using.
I need to linearise this graph and draw a best fit linear line but I have no clue how to do it. What should I do?
The table on the left shows the raw data. The first column is showing the values for x-axis, and the second is for y-axis. According to my hypothesis, the y-value should initially increase as x-value increases from 0; the y-value is then expected to decrease to zero as x-value increases further.
 

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Try taking the logarithm of the data and plotting them again to see if you can come up with a "linear" line.

So, plot:
  • log x vs. y
  • log x vs. log y
  • x vs. log y
From my experience, that's how you would "linearize" data.
 
If you really want a linear estimator, even though you say that logically it is nonlinear, then you can do a simple linear regression of the (x,y) data. There are many programs to do that.

If you want a linear regression estimator that is not linear, but accounts for the logical relationship, then you can do a multiple linear regression of the data (x, x2, y). I think you will be more satisfied with the result and it will account for the logical relationship that you believe.

The auto-fit line in your graph has done a linear regression on the data (x, x2, x3, x4, x5, y). I think that goes too far and may be unnecessary, but it is more accurate. Here is what I get from y = 40.79166667 +0.67583333*x -0.01772619 *x2.
R_multLinReg.png
 

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Let me see if I understood what you are looking for, please let me know : You want to find f with (y,f(x)) ( where {(y,x)} is your given data ) so that the plot {(y,f(x))} will be linearizable in the sense that it will pass some measure of linear goodness of fit? The plot seemed a bit like an inverted parabola , i.e., ## y-y_0 =c\sqrt x ##, so I considered the linearization ##(x, y_0+c\sqrt x)##. Am I on the right track (finding the right values for ##y_o, c## )?