Faq more info on R Squared statistic

Issue:

Can you give me more information on the R-Squared statistic?

Possible Solutions:

R-Squared (R2) is an assessment of how well the model does the prediction (it is similar to RMSEC except that it doesn't show if there is a bias).

You can access the R2 by right-clicking on a scores plot of predicted vs. measured. It is one of the items which show up in the information box ("Show on figure" puts it on the figure).

Note: in other software, R2 is for the MODELED data only. In PLS_Toolbox we calculate it for the DISPLAYED data. That means that if you show excluded data, or if you show predicted/test data with calibration data ("Show Cal with Test") the R2 will be for what is shown and will be different from the calibration data. Turn off the "Show Cal with Test" checkbox on the Plot Controls window to view the R2 for only the test data.

R2 is calculated as the square of the correlation coefficient between the X and Y axes plotted in the figure. If the only data shown is the estimation of the calibration Y data vs. the actual calibration Y data, this is nearly the same as the standard R2 for a model as defined by, e.g. Martens and Naes.