Version 4 of the Pirouette software from Infometrix has been enhanced to support process monitoring and control applications. An update of the installer was also required to handle Windows 7 32-bit and 64-bit operating systems.

The resulting new features include Random being added as a sample selection procedure, a utility for finding missing values has been added to the edit menu, a new outlier diagnostic, the Q statistic, has been added to PCA, 2-D scores plots now show a confidence ellipse and the Mahalanobis distance with the threshold calculation being modified accordingly, total contributions have been added to the renamed score contributions folder for PCA, scaling has been removed from the score contributions, an error contributions object is now computed for PCA, a misclassification matrix has been added for KNN predictions, common I/O dialogs have been upgraded, Pirouette models have been augmented with new information, merge has been split into two dialogs, one for merging as samples and one for variables, default views of computed object plots have been modified and ALS has been updated to correct for a problem with negative-going profiles.