¥ Number of equations = number of time points
H 100s per run, but perhaps 1000s per
subject
¥ Number of unknowns usually in range 5Ð50
¥ Least squares solution:
H denotes an estimate of
the true (unknown)
H From , calculate
as the fitted model
o
is the residual time series = noise (we hope)
¥ Collinearity: when
matrix canÕt be
inverted
H Near
collinearity: when inverse exists but is huge