Hi,
I have a problem that is hopefully easily solvable, but I dont find the
clue in the documentation. I am examining a linear model. One of the
variables has NA values. Even though na.action=na.omit, i get NA as
results for this variable. Can I use lm in such a case to get estimates?
Or do I have to do some form of imputation before doing so?
Here is the call and the results, hope you can help.
Best regards,
Andreas
---------------------------------------------------------------------------------------------
lm(formula = ESSIK ~ ALTER + as.factor(S2) + as.factor(S15A) +
as.factor(S8) + as.factor(LAND) + as.factor(S18B) + as.factor(BERUF) +
as.factor(KIRCHE) + as.factor(H_EINKOM) + as.factor(PARTNERS),
na.action = na.omit)
Residuals:
Min 1Q Median 3Q Max
-17.0675 -2.0151 0.4267 2.7644 9.7333
Coefficients: (2 not defined because of singularities)
Estimate Std. Error t value Pr(>|t|)
(Intercept) 23.755915 1.844110 12.882 < 2e-16 ***
[...]
as.factor(BERUF)7 -1.236836 0.701323 -1.764 0.077942 .
as.factor(KIRCHE)1 -0.811751 0.237699 -3.415 0.000649 ***
as.factor(H_EINKOM)2 NA NA NA NA
as.factor(H_EINKOM)3 NA NA NA NA
as.factor(PARTNERS)1 2.057070 0.342546 6.005 2.23e-09 ***
Hallo On 28 Jul 2005 at 18:44, Andreas Cordes wrote:> Hi, > I have a problem that is hopefully easily solvable, but I dont find > the clue in the documentation. I am examining a linear model. One of > the variables has NA values. Even though na.action=na.omit, i get NA > as results for this variable. Can I use lm in such a case to get > estimates? Or do I have to do some form of imputation before doing so? > Here is the call and the results, hope you can help. Best regards, > Andreas > ---------------------------------------------------------------------- > ----------------------- lm(formula = ESSIK ~ ALTER + as.factor(S2) + > as.factor(S15A) + > as.factor(S8) + as.factor(LAND) + as.factor(S18B) + > as.factor(BERUF) + as.factor(KIRCHE) + as.factor(H_EINKOM) + > as.factor(PARTNERS), na.action = na.omit) > > Residuals: > Min 1Q Median 3Q Max > -17.0675 -2.0151 0.4267 2.7644 9.7333 > > Coefficients: (2 not defined because of singularities)Problem is not in NA handling but that some of your coeficients can be represented as linear combination of other coeficients. You have to omit them. HTH Petr> Estimate Std. Error t value Pr(>|t|) > (Intercept) 23.755915 1.844110 12.882 < 2e-16 *** > [...] > as.factor(BERUF)7 -1.236836 0.701323 -1.764 0.077942 . > as.factor(KIRCHE)1 -0.811751 0.237699 -3.415 0.000649 *** > as.factor(H_EINKOM)2 NA NA NA NA > as.factor(H_EINKOM)3 NA NA NA NA > as.factor(PARTNERS)1 2.057070 0.342546 6.005 2.23e-09 *** > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.htmlPetr Pikal petr.pikal at precheza.cz
Also have a look at this thread from last week https://stat.ethz.ch/pipermail/r-help/2005-July/074550.html Regards, Adai On Thu, 2005-07-28 at 18:59 +0200, Petr Pikal wrote:> Hallo > > On 28 Jul 2005 at 18:44, Andreas Cordes wrote: > > > Hi, > > I have a problem that is hopefully easily solvable, but I dont find > > the clue in the documentation. I am examining a linear model. One of > > the variables has NA values. Even though na.action=na.omit, i get NA > > as results for this variable. Can I use lm in such a case to get > > estimates? Or do I have to do some form of imputation before doing so? > > Here is the call and the results, hope you can help. Best regards, > > Andreas > > ---------------------------------------------------------------------- > > ----------------------- lm(formula = ESSIK ~ ALTER + as.factor(S2) + > > as.factor(S15A) + > > as.factor(S8) + as.factor(LAND) + as.factor(S18B) + > > as.factor(BERUF) + as.factor(KIRCHE) + as.factor(H_EINKOM) + > > as.factor(PARTNERS), na.action = na.omit) > > > > Residuals: > > Min 1Q Median 3Q Max > > -17.0675 -2.0151 0.4267 2.7644 9.7333 > > > > Coefficients: (2 not defined because of singularities) > > Problem is not in NA handling but that some of your coeficients > can be represented as linear combination of other coeficients. You > have to omit them. > > HTH > Petr > > > > Estimate Std. Error t value Pr(>|t|) > > (Intercept) 23.755915 1.844110 12.882 < 2e-16 *** > > [...] > > as.factor(BERUF)7 -1.236836 0.701323 -1.764 0.077942 . > > as.factor(KIRCHE)1 -0.811751 0.237699 -3.415 0.000649 *** > > as.factor(H_EINKOM)2 NA NA NA NA > > as.factor(H_EINKOM)3 NA NA NA NA > > as.factor(PARTNERS)1 2.057070 0.342546 6.005 2.23e-09 *** > > > > ______________________________________________ > > R-help at stat.math.ethz.ch mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide! > > http://www.R-project.org/posting-guide.html > > Petr Pikal > petr.pikal at precheza.cz > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html >