Re: [R] missing values in step procedure

From: Bernardo Rangel Tura <tura_at_centroin.com.br>
Date: Sat 08 Oct 2005 - 18:34:25 EST


At 11:11 7/10/2005, you wrote:

>Hi,
>I have the problem that for the step procedure stops due to missing
>values. There are no options in Step or stepAIC to handle missing
>values. Is there any way to run stepwise modelselection in R in an
>automated way in this case?
>
>Here is the last step before it stops. Hope someone knows. Best regards,
>Andreas
>
>Step: AIC= 1999.16
> EF ~ SF120_KS + SF120_PS + HADA0 + SOZU0 + LVEDD + logPROBNP +
> ALTER + SD0_01 + ASE_UK + DS140POS + RSQSICH0 + SD0_01:ASE_UK +
> SD0_01:DS140POS + SD0_01:RSQSICH0 + ASE_UK:DS140POS +
>ASE_UK:RSQSICH0 +
> DS140POS:RSQSICH0 + SD0_01:ASE_UK:RSQSICH0 +
>SD0_01:DS140POS:RSQSICH0 +
> ASE_UK:DS140POS:RSQSICH0
>
> Df Sum of Sq RSS AIC
>- SOZU0 1 3.0 25356.0 1997.2
>- HADA0 1 7.6 25360.6 1997.3
>- ALTER 1 13.0 25365.9 1997.4
>- SF120_PS 1 14.7 25367.6 1997.5
>- ASE_UK:DS140POS:RSQSICH0 1 20.1 25373.1 1997.6
>- SD0_01:DS140POS:RSQSICH0 1 44.8 25397.7 1998.0
>- SD0_01:ASE_UK:RSQSICH0 1 54.4 25407.4 1998.2
><none> 25352.9 1999.2
>- LVEDD 1 382.2 25735.1 2004.6
>- SF120_KS 1 476.4 25829.3 2006.4
>- logPROBNP 1 891.9 26244.9 2014.4
>Error in step(mod2, direction = "back") :
> number of rows in use has changed: remove missing values?

Andreas

Try

data<-na.omit(original database) before you run step() or stepAIC()

Bernardo Rangel Tura, MD, MSc
National Institute of Cardiology Laranjeiras Rio de Janeiro Brazil

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Received on Sat Oct 08 18:38:55 2005

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