Inverse Gaussian Distribution

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Inverse Gaussian Distribution

Louisa
Dear,

I want to fit an inverse gaussion distribution to a data set.

The predictor variables are gender, area and agecategory.
For each of these variables I've defined a baseline

e.g.
#agecat: baseline is 3
data<-transform(data, agecat=C(factor(agecat,ordered=TRUE), contr.treatment(n=6,base=3)))

The variable 'area' goes from A to F (6 areas: A,B,C,D,E,F)

How can i manipulate the data to set the baseline of area to C?
R is producing errors when I'm trying to do so.

I'll be very thankful for any help you can provide.

Louisa
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Re: Inverse Gaussian Distribution

David Winsemius

On Jan 3, 2011, at 3:03 PM, Louisa wrote:

>
> Dear,
>
> I want to fit an inverse gaussion distribution to a data set.
>
> The predictor variables are gender, area and agecategory.
> For each of these variables I've defined a baseline
>
> e.g.
> #agecat: baseline is 3
> data<-transform(data, agecat=C(factor(agecat,ordered=TRUE),
> contr.treatment(n=6,base=3)))
>
> The variable 'area' goes from A to F (6 areas:
>
> How can i manipulate the data to set the baseline of area to C?
> R is producing errors when I'm trying to do so.

In all likelihood it's a factor. Try
area <- factor(area, levels=c("C", "A","B","D","E","F") )


If not, then you need to provide more information. Read the Posting  
Guide.

>
> I'll be very thankful for any help you can provide.
>
> Louisa
> --
> View this message in context: http://r.789695.n4.nabble.com/Inverse-Gaussian-Distribution-tp3172533p3172533.html
> Sent from the R help mailing list archive at Nabble.com.
>


David Winsemius, MD
West Hartford, CT

______________________________________________
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
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Re: Inverse Gaussian Distribution

djmuseR
In reply to this post by Louisa
Hi:

"How can i manipulate the data to set the baseline of area to C?
R is producing errors when I'm trying to do so."

See ?relevel

Dennis

On Mon, Jan 3, 2011 at 12:03 PM, Louisa <[hidden email]> wrote:

>
> Dear,
>
> I want to fit an inverse gaussion distribution to a data set.
>
> The predictor variables are gender, area and agecategory.
> For each of these variables I've defined a baseline
>
> e.g.
> #agecat: baseline is 3
> data<-transform(data, agecat=C(factor(agecat,ordered=TRUE),
> contr.treatment(n=6,base=3)))
>
> The variable 'area' goes from A to F (6 areas: A,B,C,D,E,F)
>
> How can i manipulate the data to set the baseline of area to C?
> R is producing errors when I'm trying to do so.
>
> I'll be very thankful for any help you can provide.
>
> Louisa
> --
> View this message in context:
> http://r.789695.n4.nabble.com/Inverse-Gaussian-Distribution-tp3172533p3172533.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

        [[alternative HTML version deleted]]

______________________________________________
[hidden email] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
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Re: Inverse Gaussian Distribution

Louisa
In reply to this post by Louisa
Thank you!

But i'm wondering:

if you run
 
area <- factor(area, levels=c("C", "A","B","D","E","F") )

then you are transforming only 'area',  aren't you?

isn't it possible to transform the whole data like i did for agecat
but now for area and area C as baseline,

or are you doing so when you run

> area <- factor(area, levels=c("C", "A","B","D","E","F") )
> attach(data)

and then run the model with area as predictorvariable:

 > model <- glm(Y~ agecat+gender+area,...)

My question is if i can run it as follows and still have a right solution :

> data <-transform(data, area=(factor(area, levels=c("C", "A","B","D","E","F") ) )

I'll be very grateful for any help you can provide!

Kind regards,

Louisa

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Re: Inverse Gaussian Distribution

David Winsemius

On Jan 4, 2011, at 7:50 AM, Louisa wrote:

>
> Thank you!
>
> But i'm wondering:
>
> if you run
>
> area <- factor(area, levels=c("C", "A","B","D","E","F") )
>
> then you are transforming only 'area',  aren't you?
>
> isn't it possible to transform the whole data like i did for agecat
> but now for area and area C as baseline,

Of course, but may I point out that you did no earlier say that you  
may have attached a dataframe containing "area". There are many  
confusing situations that arise when using attached dataframes and  
this may be one of them. Many experienced R users avoid attaching data  
objects like the plague.

>
> or are you doing so when you run
>
>> area <- factor(area, levels=c("C", "A","B","D","E","F") )
>> attach(data)
>
> and then run the model with area as predictorvariable:
>
>> model <- glm(Y~ agecat+gender+area,...)

>
> My question is if i can run it as follows and still have a right  
> solution :
>
>> data <-transform(data, area=(factor(area, levels=c("C",
>> "A","B","D","E","F") ) )

Is there any reason that you suspect this will not work? Why not try  
it ... now assumimg that you failed to tell us that area was a column  
in a dataframe that is. (One set of parentheses appear extraneous.)

data <-transform(data, area = factor(area, levels=c("C",  
"A","B","D","E","F") )

(Untested in the absence of reproducible example ,,, but it looks as  
though it might work.)

>
> I'll be very grateful for any help you can provide!
>
> Kind regards,
>
> Louisa
>
>
> --
> View this message in context: http://r.789695.n4.nabble.com/Inverse-Gaussian-Distribution-tp3172533p3173468.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

David Winsemius, MD
West Hartford, CT

______________________________________________
[hidden email] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
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Re: Inverse Gaussian Distribution

Louisa
Thank you again David!

I did not try it yet, cause neither the dataset nor R is on this computer.
I'll try it in a few hours, as soon as possible, when I'm on my personal computer.

I'll let you know if it works. I'm really curious!

Thank you for your time!

Best Wishes,
Louisa
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Re: Inverse Gaussian Distribution

Louisa
Dear David,
It works!
Thank you so much for your help!
Louisa