Texas Instruments TI-Nspire CAS

List arguments containing void elements
In regressions, a void in an X or Y list
introduces a void for the corresponding
element of the residual.
An omitted category in regressions
introduces a void for the corresponding
element of the residual.
A frequency of 0 in regressions introduces a
void for the corresponding element of the
residual.
Empty (Void) Elements 233