[R] Accessing Results from cenmle function in NADA package
Tom La Bone
booboo at gforcecable.com
Wed Nov 12 17:37:54 CET 2008
This is very nice also. I am going to use this approach in the future when I
use lm. However, I can't seem to get to work the way I want with cenmle. I
will continue to experiment. Thanks folks for the suggestions.
Tom
David Winsemius wrote:
>
>
> On Nov 12, 2008, at 8:48 AM, Tom La Bone wrote:
>
>>
>> I figured it out. In case anyone else ever has this question --
>> given the
>> following output from cenmle:
>>
>>> fit.cen <- cenmle(obs, censored, groups)
>>> fit.cen
>> Value Std. Error z p
>> (Intercept) 1.19473 0.0772 15.4695 5.58e-54
>> groups1 0.00208 0.0789 0.0263 9.79e-01
>> Log(scale) -0.40221 0.0168 -23.9034 2.82e-126
>>
>> Scale= 0.669
>>
>> Log Normal distribution
>> Loglik(model)= -3908.9 Loglik(intercept only)= -3908.9
>> Loglik-r: 0.0006265534
>>
>> Chisq= 0 on 1 degrees of freedom, p= 0.98
>> Number of Newton-Raphson Iterations: 1
>> n = 1766
>>
>> The p-value is (for example):
>>
>> p.value <- summary(fit.cen)[[9]][[11]]
>
> An approach that may yield somewhat more self-documenting code would
> be to examine either the fit object or the summary object with str and
> then to access results by extracting named elements. Since I don't
> have the package in question, let me use the lm object on its help
> page as an example:
>
> ctl <- c(4.17,5.58,5.18,6.11,4.50,4.61,5.17,4.53,5.33,5.14)
> trt <- c(4.81,4.17,4.41,3.59,5.87,3.83,6.03,4.89,4.32,4.69)
> group <- gl(2,10,20, labels=c("Ctl","Trt"))
> weight <- c(ctl, trt)
> lm.D9 <- lm(weight ~ group)
>
> str(lm.D9)
> str(summary(lm.D9))
> summary(lm.D9)$coefficients
> summary(lm.D9)$coefficients["groupTrt", "Pr(>|t|)"]
>
> # to get the p-value
> > summary(lm.D9)$coefficients["groupTrt","Pr(>|t|)"]
> [1] 0.2490232
>
> You had originally asked for a method to extract coefficients and for
> that purpose you may want to look at:
>
> ?coefficients
>
> > slope <- coefficients(lm.D9)["groupTrt"]
> > slope
> groupTrt
> -0.371
>
> --
> David Winsemius
> Heritage Labs
>
>>
>> Tom
>>
>>
>>
>>
>> Tom La Bone wrote:
>>>
>>> The cenmle function is used to fit two sets of censored data and
>>> test if
>>> they are significantly different. I can print out the results of the
>>> analysis on the screen but can't seem to figure out how to access
>>> these
>>> results in R and assign them to new variables, e.g., assign the slope
>>> calculated with cenmle to the variable m. Any suggestions?
>>>
>>> Tom
>>>
>>
>> --
>> View this message in context:
>> http://www.nabble.com/Accessing-Results-from-cenmle-function-in-NADA-package-tp20437420p20460676.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
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>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> 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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