> On 26 Sep 2016, at 19:41, Matti Viljamaa <mvilja...@kapsi.fi> wrote:
>
> Thank you.
>
> However, I’m having some trouble converting your code to use clka, because
> the model I was using was:
>
> fit2 <- lm(ruotsi.pist ~ mies + koulu + clka + koulu*clka, data=dta)
I mean, not to use clka to replace lka. But to use the above fit2, rather than
your fit2.
>> On 25 Sep 2016, at 21:23, Jeff Newmiller <jdnew...@dcn.davis.ca.us> wrote:
>>
>> This illustrates why you need to post a reproducible example. You have a
>> number of confounding factors in your code.
>>
>> First, "data" is a commonly-used function... avoid using it for variable
>> names.
>>
>> Second, using the attach function this way leads to confusion... best to
>> forget this function until you start building packages.
>>
>> Third, clka is linearly dependent on lka, so having them both in the
>> regression is not possible. In this case lm has chosen to ignore clka so
>> that bs("clka") is NA.
>>
>> Fourth, curve expects you to give it a function, and instead you have given
>> it a vector.
>>
>> Fifth, you are plotting versus lka, but attempting to vary clka in the curve
>> call.
>>
>> There are a number of directions you could go with this to get a working
>> output... below is my version.
>>
>> dta <- read.table(
>> "http://users.jyu.fi/~slahola/files/glm1_datoja/yoruotsi.txt";, header=TRUE )
>> fit2 <- lm( ruotsi.pist ~ mies + koulu*lka, data=dta )
>> bs <- coef( fit2 )
>> rpBylka <- function( lka ) {
>> kouluB <- factor( "B", levels = levels( dta$koulu ) )
>> newdta <- expand.grid( mies=0, koulu=kouluB, lka=lka )
>> predict( fit2, newdata = newdta )
>> }
>> dtaKouluB <- subset( dta, koulu == "B" )
>> varitB <- dtaKouluB$mies
>> varitB[ varitB == 0 ] <- 2
>> plot( dtaKouluB$lka
>> , dtaKouluB$ruotsi.pist
>> , col=varitB
>> , pch=16
>> , xlab='lka'
>> , ylab='ruotsi.pist'
>> , main='Lukio B'
>> )
>> curve( rpBylka, from = min( dta$lka ), max( dta$lka ), add=TRUE, col="red" )
>>
>> On Sun, 25 Sep 2016, Matti Viljamaa wrote:
>>
>>>
>>>> On 25 Sep 2016, at 19:37, Matti Viljamaa <mvilja...@kapsi.fi> wrote:
>>>>
>>>> Okay here?s a pretty short code to reproduce it:
>>>>
>>>> data <-
>>>> read.table("http://users.jyu.fi/~slahola/files/glm1_datoja/yoruotsi.txt";,
>>>> header=TRUE)
>>>
>>> data$clka <- I(data$lka - mean(data$lka))
>>>
>>>> attach(data)
>>>>
>>>> fit2 <- lm(ruotsi.pist ~ mies + koulu + lka + koulu*clka)
>>>>
>>>> bs <- coef(fit2)
>>>>
>>>> varitB <- c(data[koulu == 'B',]$mies)
>>>> varitB[varitB == 0] = 2
>>>> plot(data[data$koulu == 'B',]$lka, data[koulu == 'B',]$ruotsi.pist,
>>>> col=varitB, pch=16, xlab='', ylab='', main='Lukio B?)
>>>>
>>>> curve(bs["(Intercept)"]+bs["mies"]*0+bs["kouluB"]+bs["lka"]*x+bs["kouluB:clka"]*clka,
>>>> from=min(lka), to=max(lka), add=TRUE, col='red')
>>>>
>>>>
>>>>> On 25 Sep 2016, at 19:24, Jeff Newmiller <jdnew...@dcn.davis.ca.us> wrote:
>>>>>
>>>>> Go directly to C. Do not pass go, do not collect $200.
>>>>>
>>>>> You think curve does something, but you are missing what it actually
>>>>> does. Since you don't seem to be learning from reading ?curve or from our
>>>>> responses, you need to give us an example you can learn from.
>>>>> --
>>>>> Sent from my phone. Please excuse my brevity.
>>>>>
>>>>> On September 25, 2016 9:04:09 AM PDT, mviljamaa <mvilja...@kapsi.fi>
>>>>> wrote:
>>>>>> On 2016-09-25 18:52, Jeff Newmiller wrote:
>>>>>>> You seem to be confused about what curve is doing vs. what you are
>>>>>>> doing.
>>>>>>
>>>>>> But my x-range in curve()'s parameters from and to should be the entire
>>>>>>
>>>>>> lka vector, since they are from=min(lka) and to=max(lka). Then why does
>>>>>>
>>>>>> this not span the entire of lka? Because of duplicate entries or what?
>>>>>>
>>>>>> It seems like I cannot use curve(), since my x-axis must be exactly lka
>>>>>>
>>>>>> for the function to plot the y value for every lka value.
>>>>>>
>>>>>>> A) Compute the points you want to plot and put them into 2 vectors.
>>>>>>> Then figure out how to plot those vectors. Then (perhaps) consider
>>>>>>> putting that all into one line of code again.
>>>>>>>
>>>>>>> B) The predict function is the preferred way to compute points. It
>>>>>> may
>>>>>>> be educational for you to do the computations by hand at first, but
>>>>>> in
>>>>>>> the long run using predict will help you avoid problems getting the
>>>>>>> equations right in multiple places in your script.
>>>>>>>
>>>>>>> C) Learn what makes an example reproducible (e.g. [1] or [2]), and
>>>>>> ask
>>>>>>> your questions with reproducible code and data so we can give you
>>>>>>> concrete responses.
>>>>>>>
>>>>>>> [1] http://adv-r.had.co.nz/Reproducibility.html
>>>>>>> [2]
>>>>>>>
>>>>>> http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example
>>>>>>> --
>>>>>>> Sent from my phone. Please excuse my brevity.
>>>>>>>
>>>>>>> On September 25, 2016 8:36:49 AM PDT, mviljamaa <mvilja...@kapsi.fi>
>>>>>>> wrote:
>>>>>>>> On 2016-09-25 18:30, Duncan Murdoch wrote:
>>>>>>>>> On 25/09/2016 9:10 AM, Matti Viljamaa wrote:
>>>>>>>>>> Writing:
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>
>>>>>> bs["(Intercept)"]+bs["mies"]*0+bs["kouluB"]+bs["lka"]*lka+bs["kouluB:clka"]*clka
>>>>>>>>>>
>>>>>>>>>> i.e. without that being inside curve produces a vector of length
>>>>>>>> 375.
>>>>>>>>>>
>>>>>>>>>> So now it seems that curve() is really skipping some
>>>>>> lka-/x-values.
>>>>>>>>>
>>>>>>>>> How could curve() know what the length of lka is? You're telling
>>>>>> it
>>>>>>>>> to set x to a sequence of values of length 101 (the default) from
>>>>>>>>> min(lka) to max(lka). You never tell it to set x to lka.
>>>>>>>>>
>>>>>>>>> curve() is designed to plot expressions or functions, not vectors.
>>>>>>>> If
>>>>>>>>> you actually want to plot line segments using your original data,
>>>>>> use
>>>>>>>>> lines(). (You'll likely need to sort your x values into increasing
>>>>>>>>> order if you do that, or you'll get a pretty ugly plot.)
>>>>>>>>>
>>>>>>>>> Duncan Murdoch
>>>>>>>>
>>>>>>>> I know that about curve(), but since this function uses lka as a
>>>>>>>> parameter, then how should I formulate it for curve so that I don't
>>>>>>>> get
>>>>>>>>
>>>>>>>> the error about wrong lengths?
>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>> On 25 Sep 2016, at 16:01, Matti Viljamaa <mvilja...@kapsi.fi>
>>>>>>>> wrote:
>>>>>>>>>>>
>>>>>>>>>>> I?m trying to plot regression lines using curve()
>>>>>>>>>>>
>>>>>>>>>>> The way I do it is:
>>>>>>>>>>>
>>>>>>>>>>> bs <- coef(fit2)
>>>>>>>>>>>
>>>>>>>>>>> and then for example:
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>
>>>>>> curve(bs["(Intercept)"]+bs["mies"]*0+bs["kouluB"]+bs["lka"]*x+bs["kouluB:clka"]*clka,
>>>>>>>>
>>>>>>>>>>> from=min(lka), to=max(lka), add=TRUE, col='red')
>>>>>>>>>>>
>>>>>>>>>>> This above code runs into error:
>>>>>>>>>>>
>>>>>>>>>>> Error in curve(bs["(Intercept)"] + bs["mies"] * 0 + bs["kouluB"]
>>>>>> +
>>>>>>>>>>> bs["lka"] * :
>>>>>>>>>>> 'expr' did not evaluate to an object of length 'n'
>>>>>>>>>>> In addition: Warning message:
>>>>>>>>>>> In bs["(Intercept)"] + bs["mies"] * 0 + bs["kouluB"] + bs["lka"]
>>>>>> *
>>>>>>>> :
>>>>>>>>>>> longer object length is not a multiple of shorter object length
>>>>>>>>>>>
>>>>>>>>>>> Which I?ve investigated might be related to the lengths of the
>>>>>>>>>>> different objects being multiplied or summed.
>>>>>>>>>>> Taking length(g$x) or length(g$y) of
>>>>>>>>>>>
>>>>>>>>>>> g <-
>>>>>> curve(bs["(Intercept)"]+bs["mies"]*0+bs["kouluB"]+bs["lka"]*x,
>>>>>>>>
>>>>>>>>>>> from=min(lka), to=max(lka), add=TRUE, col='red')
>>>>>>>>>>>
>>>>>>>>>>> returns 101.
>>>>>>>>>>>
>>>>>>>>>>> However length(lka) is 375. But perhaps these being different is
>>>>>>>> not
>>>>>>>>>>> the problem?
>>>>>>>>>>>
>>>>>>>>>>> I however do see that the whole range of lka is not plotted, for
>>>>>>>> some
>>>>>>>>>>> reason. So how can I be sure
>>>>>>>>>>> that it passes through all x-values in lka? And i.e. that the
>>>>>>>> lengths
>>>>>>>>>>> of objects inside curve() are correct?
>>>>>>>>>>>
>>>>>>>>>>> What can I do?
>>>>>>>>>>
>>>>>>>>>> ______________________________________________
>>>>>>>>>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>>>>>>>>> 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.
>>>>>>>>>>
>>>>>>>>
>>>>>>>> ______________________________________________
>>>>>>>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>>>>>>> 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.
>>>>>
>>>>
>>>
>>>
>>
>> ---------------------------------------------------------------------------
>> Jeff Newmiller The ..... ..... Go Live...
>> DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live Go...
>> Live: OO#.. Dead: OO#.. Playing
>> Research Engineer (Solar/Batteries O.O#. #.O#. with
>> /Software/Embedded Controllers) .OO#. .OO#. rocks...1k
>> ---------------------------------------------------------------------------
>
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