Displaying 3 results from an estimated 3 matches for "coeffficients".
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coefficients
2004 Mar 03
1
Confusion about coxph and Helmert contrasts
...rdering of the levels?
I am confused about the fact, that coefficients for different levels are
calculated, depending on weather i include level 0 or not:
If level 0 is included, with both contrasts coxph calculates
coefficients for group 1 ... group 5.
But if i exclude level 0, coxph calculates coeffficients for
group 2 ... 5 with treatment and coefficients for group 1 ... 4 using
helmert:
> options(contrasts = c("contr.treatment", "contr.poly"))
> cox.t <- coxph(Surv(time,cens) ~ as.factor(group), data=data)
> options(contrasts = c("contr.helmert", "c...
2009 May 20
1
stationarity tests
How can I make sure the residual signal, after subtracting the trend extracted through some technique, is actually trend-free ?
I would greatly appreciate any suggestion about some Stationarity tests.
I'd like to make sure I have got the difference between ACF and PACF right.
In the following I am citing some definitions. I would appreciate your thoughts.
ACF(k) estimates the correlation
2006 Jul 18
4
How can I extract information from list which class is nls
Hello!
I work with :
R : Copyright 2006, The R Foundation for
Statistical Computing
Version 2.3.1 (2006-06-01)
On Windows XP Professional (Version 2002) SP2.
At this moment I use the function "nls" combined
with a selfStar model (SSmicmen, related to
Michaelis-Menten equation, and provided by the
"stats" package).
When I realise the following operation (cf. p 59
of the