Displaying 5 results from an estimated 5 matches for "gretschel".
2011 Mar 16
5
R² for non-linear model
Dear List,
how can I obtain the value of r suqared for a non-linear model? For
linear models it can be found in the summary() of the model but for
non-linear models I just don't know. Please help!
Anna
2011 Aug 18
2
what characteristics of model curve do parameters denote
...'s the
model:
modPoplar<- nls(Diameter ~ d*(1-exp(-b *Age))^a ,start=list(a=20,b=0.9,d=33))
I attached the graph, too.
Hoping for your answers!
Best, Anna
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Telefon: 01577-7805329
E-Mail: gretschel.anna at googlemail.com
2011 Mar 05
2
testing power of correlation
Dear List,
does anyone know how I can test the strength of a correlation?
Cheers, Anna
2011 Aug 17
1
Interpreting parameters of sigmoid fct
Dear list,
I'm trying to fit a chapman-richards equation to my data, only I
cannot interpret the parameters a, b and d. I know that the parameter
b denotes the asymptote, but for the others I couldn't figure out. But
I do need to know this in order to set my starting values. Here's the
model:
modPoplar<- nls(Diameter ~ d*(1-exp(-b *Age))^a ,start=list(a=20,b=0.9,d=33))
I attached
2011 Mar 11
0
predicting values from model function
Dear List,
I have fitted a spherical function to my variogram using "variofit(...)"
from GeoR. Now I would like to predict some data with the function
"predict(object,...)" from package stats. Does anyone know wether this
works and if it does how to do it?
Thanks a lot!
Anna