Displaying 3 results from an estimated 3 matches for "tstdf".

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2003 Jun 22

1

Using weighted.mean() in aggregate()

Dear R users, I have a question on using weighted.mean() while aggregating a
data frame. I have a data frame with columns Sub, Length and Slope:
> x[1:5,]
Sub Length Slope
1 2 351.547 0.0025284969
2 2 343.738 0.0025859390
3 1 696.659 0.0015948968
4 2 5442.338 0.0026132544
5 1 209.483 0.0005304225
and I would like to calculate the weighted.mean of Slope, using Length

2004 Dec 04

1

AIC, AICc, and K

How can I extract K (number of parameters) from an AIC calculation, both to
report K itself and to calculate AICc? I'm aware of the conversion from AIC ->
AICc, where AICc = AIC + 2K(K+1)/(n-K-1), but not sure of how K is calculated
or how to extract that value from either an AIC or logLik calculation.
This is probably more of a basic statistics question than an R question, but I

2005 Jul 15

1

2D contour predictions

Hi All
I have been fitting regression models and would now like to produce some
contour & image plots from the predictors.
Is there an easy way to do this? My current (newbie) experience with R
would suggest there is but that it's not always easy to find it!
f3 <- lm( fc ~ poly( speed, 2 ) + poly( torque, 2 ) + poly( sonl, 2 ) +
poly( p_rail, 2 ) + poly( pil_sep, 2 ) + poly( maf, 2