
comes to estimating the point in time where the discontinuity function is zero. One approach is
illustrated in Figure 6.57.
The first step is to fi t a linear function through the pts (t
i
, f
old
) and (t
i
þT, f
new
), where t
i
, f
old
and f
new
are provided as inputs to ‘‘INTRP.m.’’ The root of the linear function occurs at t
i
þbT,
where
b ¼
f
old
f
old
f
new
(0 < b < 1)(6:319)
The time t
i
þbT can be treated as the pt where the discontinuity function is approximately zero.
However, an i mproved estimate is possible if we determine f
0
, t he value of the discontinuity
function at t
i
þbT, and generate the quadratic function through all three pts, namely, (t
i
, f
old
),
(t
i