Displaying 3 results from an estimated 3 matches for "1.12779".
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1.12771
2008 Jun 06
1
How to force two regression coefficients to be equal but opposite in sign?
Is there a way to set up a regression in R that forces two coefficients
to be equal but opposite in sign?
I'm trying to setup a model where a subject appears in a pair of
environments where a measurement X is made. There are a total of 5
environments, one of which is a baseline. But each observation is for
a subject in only two of them, and not all subjects will appear in
each
2008 Jun 09
1
Systemfit (was RE: How to force two regression coefficients to be equal but opposite in sign?)
Thank you, Greg, and also to Scott Ellison, who replied privately. I am
in the process of trying out both suggestions.
After I sent my initial message, I came across the Systemfit package,
which allows specification of constraints on parameters. In theory,
this should solve my problem perfectly. However, I was not able to get
it to work with my data, as every attempt yielded the following
2008 Jun 06
6
Subsetting to unique values
I want to take the first row of each unique ID value from a data frame.
For instance
> ddTable <-
data.frame(Id=c(1,1,2,2),name=c("Paul","Joe","Bob","Larry"))
I want a dataset that is
Id Name
1 Paul
2 Bob
> unique(ddTable)
Will give me all 4 rows, and
> unique(ddTable$Id)
Will give me c(1,2), but not accompanied by the name column.