# [R] R question - combine values

markleeds at verizon.net markleeds at verizon.net
Thu Feb 26 07:05:04 CET 2009

```Hi: John Fox's recode function in his car package provides a convenient
way for doing what
you need. I don't know what your factor is specifically but below is
mostly taken out
of the help for "recode" and shows how to take a factor and recode it to
make it a new
factor. you can apply that for your particular problem.

x <- gl(3,3,length=9)
print(x)
print(str(x))

temp <- recode(x,"1:2 = 'A'; 3 = 'B'")
print(temp)
print(str(temp))

On Wed, Feb 25, 2009 at 10:33 PM, choonhong ang wrote:

> The district a is the baseline and we observe the difference between
> District a & b is not significant, we can choose to combine these 2
> values.
> How to write code to combine these 2 value ?
>
>> m1=glm(Claims~District+Group+Age+log(Holders),fami
>> ly=poisson,data=mydata)
>> summary(m1)
>
> Call:
> glm(formula = Claims ~ District + Group + Age + log(Holders),
> family = poisson, data = mydata)
>
> Deviance Residuals:
> Min 1Q Median 3Q Max
> -2.553115 -0.471819 0.002411 0.455274 1.800739
>
> Coefficients:
> Estimate Std. Error z value Pr(>|z|)
> (Intercept) -2.777752 0.689162 -4.031 5.56e-05 ***
> Districtb 0.119942 0.079861 1.502 0.133125
> Districtc 0.228371 0.144503 1.580 0.114019
> Districtd 0.571661 0.248792 2.298 0.021576 *
> Group>2l 0.794721 0.180354 4.406 1.05e-05 ***
> Group1-1.5l -0.003496 0.127947 -0.027 0.978202
> Group1.5-2l 0.379190 0.055856 6.789 1.13e-11 ***
> Age>35 -1.074971 0.389480 -2.760 0.005780 **
> Age25-29 -0.332131 0.129512 -2.564 0.010333 *
> Age30-35 -0.539815 0.160138 -3.371 0.000749 ***
> log(Holders) 1.201696 0.144135 8.337 < 2e-16 ***
> ---
> Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
>
> (Dispersion parameter for poisson family taken to be 1)
>
> Null deviance: 4236.68 on 63 degrees of freedom
> Residual deviance: 49.45 on 53 degrees of freedom
> AIC: 388.77
>
>
>      ------------------------------
>
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```