Displaying 3 results from an estimated 3 matches for "coeffficient".
Did you mean:
coefficient
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", "...
2009 May 20
1
stationarity tests
...y(t-k) like an ordinary correlation coefficient.
ACF is the simple ( i.e. unconditional ) correlation between a time series and it's lags thus
y(t)=a+b*y(t-k) gnerates the kth autocoreelation coefficient (b).
If we have form y(t)=a+b*y(t-1)+c*y(t-2) .. then (c) is the PARTIAL AUTOCORRELATION COEFFFICIENT or in other words the
CONDITIONAL CORRELATION of lag 2 given lag1
PACF(k) estimates the correlation between y(t) and y(t-k) adjusted for the effects of y(t-1), ..., y(t-k+1).
Model identification is achieved by looking at the pattern of the ACF and PACF.
- If the ACF dies off exponentially, but th...
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