Y-residuals

Contain the remaining variance in the responses not explained by the PLS model. Observations with relatively large y-residuals are outliers in the y-space, indicating that they are not well explained by the model.

The y-residuals are the differences between the actual response values and y-calculated values, and are on the same scale as the original responses. The y-residual matrix, similar to the original y-matrix, is an n x r matrix, where n = number of observations and r = number of responses.