What would you like to see in a future HP Prime II? (HP Prime², HP Prime 2X)

[Jenab6]

I want an HP Prime II that has a much greater diversity of function types to model data with.

To see the types that the HP Prime II has already, choose the "Statistics 2Var" app, press [symb] button, and then click on the drop-down menu for "Type 1". You'll see:

Linear
Logarithmic
Exponential
Power
Exponent
Inverse
Logistic
Quadratic
Cubic
Quartic
Trigonometric
Median-Median
User Defined

Now, you'd think that the "user defined" option would take care of everything, but it doesn't. For example, the "Logistical" option gives this function type:

y = L / { 1 + A*e^(-Bx) }

But there are other logistical forms that offer curvefitting solutions at least as good (often better) than the standard one shown above. One of those other forms is:

y = A - B / { 1 + (x/C)^D }

If you try typing the stuff on the right of the equals into the "user defined" option's definition box, the HP Prime II will NOT solve for the least-squares solution for the coefficients, and it will NOT graph any curve with the data when you press the [Plot] button.

As things are, the HP Prime II has a rudimentary set of curve-fitting function types, and I'd very much appreciate it if the types could be greatly expanded. For ideas, you might browse over to ZunZunSite or https://mycurvefit.com or MathWorks. There are lots of websites that do what the HP Prime II ought to do for users who have data that needs to have curves fit to them.

While you're at it, think about putting in a Fast Fourier Transform function, too.