R help - Mar 2012 - Problems with generalized linear model (glm) coefficients.

Hello to everyone.

I´m writing you because I´m feeling a bit frustrated with my work.

My work consists in finding  the relation between the amount of fires and
the weather, so, my response variable is the amount of fires in a fire
season and the explanatory variables are the temperature, the amount of
precipitation and the some others…. my problem is this; I keep getting the
wrong sign in the coefficients estimated, I get a negative sign for
temperature and a positive sign for precipitation, which is unreasonable,
the greater the temperature I would expect more fire, on the contrary, the
greater the precipitation I would expect less fires.  So far I have deal
with overdispersion, multicollinearity  and the amount of zeroes through
passing from Poisson to Negative Binomial and Hurdle.  I believe I have
used all my options and still have the wrong signs on my coefficients.

Do I have more options? What does it mean that I keep getting those signs?

If anyone could help me I would really appreciate it.

Thank you.


Lucas.

	[[alternative HTML version deleted]]

Hi Lucas,

Do you apply your analysis in time or in space?

Regards,
Pascal
?


----- Mail original -----
De?: Lucas <lpchaparrovio at gmail.com>
??: r-help at r-project.org
Cc?: 
Envoy? le : Mercredi 7 mars 2012 22h34
Objet?: [R] Problems with generalized linear model (glm) coefficients.

Hello to everyone.

I?m writing you because I?m feeling a bit frustrated with my work.

My work consists in finding? the relation between the amount of fires and
the weather, so, my response variable is the amount of fires in a fire
season and the explanatory variables are the temperature, the amount of
precipitation and the some others?. my problem is this; I keep getting the
wrong sign in the coefficients estimated, I get a negative sign for
temperature and a positive sign for precipitation, which is unreasonable,
the greater the temperature I would expect more fire, on the contrary, the
greater the precipitation I would expect less fires.? So far I have deal
with overdispersion, multicollinearity? and the amount of zeroes through
passing from Poisson to Negative Binomial and Hurdle.? I believe I have
used all my options and still have the wrong signs on my coefficients.

Do I have more options? What does it mean that I keep getting those signs?

If anyone could help me I would really appreciate it.

Thank you.


Lucas.

??? [[alternative HTML version deleted]]


______________________________________________
R-help at r-project.org 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.

PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

We have nothing at all to go on.

John Kane
Kingston ON Canada

> -----Original Message-----
> From: lpchaparrovio at gmail.com
> Sent: Wed, 7 Mar 2012 10:34:09 -0300
> To: r-help at r-project.org
> Subject: [R] Problems with generalized linear model (glm) coefficients.
> 
> Hello to everyone.
> 
> I4m writing you because I4m feeling a bit frustrated with my work.
> 
> My work consists in finding  the relation between the amount of fires and
> the weather, so, my response variable is the amount of fires in a fire
> season and the explanatory variables are the temperature, the amount of
> precipitation and the some others?. my problem is this; I keep getting
> the
> wrong sign in the coefficients estimated, I get a negative sign for
> temperature and a positive sign for precipitation, which is unreasonable,
> the greater the temperature I would expect more fire, on the contrary,
> the
> greater the precipitation I would expect less fires.  So far I have deal
> with overdispersion, multicollinearity  and the amount of zeroes through
> passing from Poisson to Negative Binomial and Hurdle.  I believe I have
> used all my options and still have the wrong signs on my coefficients.
> 
> Do I have more options? What does it mean that I keep getting those
> signs?
> 
> If anyone could help me I would really appreciate it.
> 
> Thank you.
> 
> 
> Lucas.
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at r-project.org 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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