After the data is imported into the Curve Fitting Assistant you can explore different curve fitting methods. The following data is used in this section:
$\left[1\,2comma;3comma;4comma;5comma;6comma;7comma;8\right]comma;\left[4comma;10comma;22comma;44comma;102comma;190comma;300comma;436\right]$

Figure 3  Curve Fitting Assistant



This window displays a plot of the points, an indication of the vertical range of the plot, and a selection of relevant curve fitting commands to the right. At the bottom of the window there is a box that displays the interpolant found with the selected curve fitting algorithm.
Note: Rational interpolation is only available if the data contains no decimal values. Thiele interpolation is available if the dependent variable values in the data are unique.
For the rational interpolation and splines options, sliders allow you to control the maximum degree of the numerator and denominator used in the rational interpolant, or the degree of the spline being used during the curve fitting procedure.
The least squares section provides an input box where you can specify an expression in terms of $x$. The parameters will be fit by the Least Squares command with values according to this procedure. Only expressions that are linear in terms of the parameters are allowed.
In this example, enter the expression a*x^2+b*x+c. Then click the Plot button for the least squares method to see the result.

Figure 4  Fitting a curve to the data points



Click Done to return the interpolant for the leastsquares approximation.
$\left[1\,2comma;3comma;4comma;5comma;6comma;7comma;8\right]comma;\left[4comma;10comma;22comma;44comma;102comma;190comma;300comma;436\right]$$\stackrel{\text{curve fitting assistant}}{\to}$$\frac{{346}}{{7}}{}\frac{{1018}}{{21}}{}{x}{\+}\frac{{253}}{{21}}{}{{x}}^{{2}}$
For more information on the leastsquares fitting command, see CurveFitting[LeastSquares].
The Curve Fitting Assistant allows you to explore different curve fitting algorithms and easily see the plot of the resulting curve. This interface also allows for experimenting with setting different settings for the curve fitting procedure. When you find the curve that you are looking for, you can choose to return the interpolant (equation) or the plot when you finish using the assistant.