Message-ID: <20050801081719.52138.qmail@web40602.mail.yahoo.com>
Date: 2005-08-01T08:17:18Z
From: Arie
Subject: Conditional piece-wise dependent regression
Hi, after reading some R docs, I couldn?t figure out how can I find the solution for the following
problem, therefore I would ask this friendly list for an advice.
We?re making a least square approximation for an experiment described by the following model:
T is the time,
Y is some measured value.
>From time=0 till time=U:
Y = b + p*T
>From time=U and on (some effect added):
Y = b + p*T + q*(T-U)
>From time=V and on (some additional effect added):
Y = b + p*T + q*(T-U) + r*(T-V)
Measured: Yi, Ti pairs.
Wanted: b, p, q, r.
b and p are the same for all time ranges;
q is the same for time=U and on.
Thanks,
Arie.