Topic: Finding R squared for user entered function

Hi,

My students are completing a portfolio task where they have to find the best model to fit a set of data points. They can let the computer do the work, and Insert a Curve fit for the data, which gives them an R^2 value, but when they attempt to use their knowledge of function transformation to find and enter their own function to fit the data, I can't see how to find the R^2 for their own function.  Is this possible at all?

Thanks in advance.

Re: Finding R squared for user entered function

This is possible. The way I've done this in the past is simple to right click on your data and choose Insert Trendline just like you usually would, then choose the User Defined tab and enter your function into the Model field. If you don't include any parameters then it's not REALLY a curve fit, just the function you entered. The function is created and the R^2 value is displayed.

It's a bit of a roundabout way to do it, but it works. Although sometimes I do wish you could just associate a function with a point series, and have the R^2 value displayed, and update automatically if you change the point series or the function. I would certainly use a feature like that.