[R] How to extract "specific"/"last" intercept value from segmented package.

[ruipbarradas at sapo.pt]

Hello,

I'm glad that it helped.
Note, however, that you don't need inter.m <- as.matrix(...) because  
inter$x already is a matrix.
You can simply do

inter.row <- nrow(inter$x)
answer <- inter$x[inter.row,1]

Rui Barradas
 

Citando Narendra Modi <bjpmodi2016 at gmail.com>:

> Thanks! that worked.
>
> I also tested with the below method although your solution is faster
> and done in fewer steps.
>
> inter <- intercept(segmented.mod)
> inter.m <- as.matrix(inter$x)
> inter.row <- nrow(inter.m)
> answer <- inter.m[inter.row,1]
>
> PD
>
> On Tue, Jul 5, 2016 at 2:28 PM,  <ruipbarradas at sapo.pt> wrote:
>> Hello,
>>
>> Try
>>
>> dimnames(inter$x)[[1]]
>>
>> You could have seen this by inspecting 'inter':
>>
>> str(inter)
>>
>> Hope this helps,
>>
>> Rui Barradas
>>
>> Citando Narendra Modi <bjpmodi2016 at gmail.com>:
>>
>> I am able to perform regression on a dataset as below:
>>
>> plot(x,y)
>> lin.mod <- lm(y~x)
>> m <- mean(x)
>> m
>>
>> segmented.mod <- segmented(lin.mod, seg.Z = ~x, psi= m)
>>
>> plot(segmented.mod, add=T)
>> sl <- slope(segmented.mod)
>> inter <- intercept(segmented.mod)
>>
>> summary(segmented.mod)    # Show Summary
>> sl                        # show all the slopes
>> inter                     # show all the intercepts
>>
>> In my dataset, the above method correctly identifies the breakpoints and
>> hence I get two intercepts.
>>
>> inter
>>
>> $x
>>              Est.
>> intercept1  -3.269
>> intercept2 -19.980
>>
>> What I am interested is the "intercept2" value. How can I obtain this?
>>
>> The method needs to be dynamic as in if the next dataset has 3 intercepts,
>> I would like to get "intercept3 value.
>>
>> PD
>>
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>>
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>
>  

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