User defined fit in apps Stats 2Var

[Helper]

Are you able to use the User defined it in Stats 2 Var. the predefined fit work very well but not the user defined fit
Thanks

[Tim Wessman]

The user fit basically allows you to draw a fit line onto the graph. It won't however carry through and calculate all the numerical values in the NUM->STATS calculations using the entered fit by design.

There is an issue currently that it doesn't flag your fit as being "calculated" if you start with a user fit first however. Just do one of the built in ones, then modify the formula *after* another fit has been calculated and it will work fine.

I suspect you are entering a user fit *first*, and then it won't recognize there a valid fit to draw. If this is the case, just do one of the built-ins and *then* edit the formula, and it will work properly for you.

[Helper]

i have just try your solution but it does not work. I have choosen the quadratic fit A*X^2+B*X+C, the plot is OK. Then i edit the fit field by A*X^2 and i does not work !!

[Helper]

i have just try your solution but it does not work. I have choosen the quadratic fit A*X^2+B*X+C, the plot is OK. Then i edit the fit field by A*X^2 and i does not work !!

[Tim Wessman]

(04-21-2014 08:49 PM)Helper Wrote:  Then i edit the fit field by A*X^2 and i does not work !!

And A is defined as 0 I am guessing? You thus have 0*X^2 which will be a flat line where Y=0.

Store a value of 2 into A and you will see your graph easier. The user fit does not allow you to enter any number of arbitrary variables and solve for all the variables. It is much simpler and really is just a way for the user to either modify the existing fit, or experiment with creating their own "fit" line.

[Helper]

Thanks. I have just understood that is not a real fit but only for verifying a proper expression

[dantebm88]

Can be adjusted with a polynomial of 5th grade or higher?

[Tim Wessman]

The polynomial fit it actually an Nth fit internally, so yes I suspect this will be allowed at some point.