[R] plot shows exponential values incompatible with data

[Fox, John]

Dear Bernard,

> On Jul 9, 2020, at 10:25 AM, Bernard Comcast <mcgarvey.bernard using comcast.net> wrote:
> 
> Use the xlim option in the plot function?

I think you mean ylim, but as you'll find out when you try it, you still (reasonably) get an evenly spaced tick mark at 0:

plot(Y ~ X, ylim=c(1e9, 6e11))

The "right" thing to do with exponential values is to plot on a log scale or (as Rui reasonably suggested) use a logged axis.

Best,
 John

> 
> Bernard
> Sent from my iPhone so please excuse the spelling!"
> 
>> On Jul 9, 2020, at 10:06 AM, Luigi Marongiu <marongiu.luigi using gmail.com> wrote:
>> 
>> Thank you,
>> but why it does not work in linear? With the log scale, I know it
>> works but I am not looking for it; is there a way to force a linear
>> scale?
>> Regards
>> Luigi
>> 
>>> On Thu, Jul 9, 2020 at 3:44 PM Fox, John <jfox using mcmaster.ca> wrote:
>>> 
>>> Dear Luigi,
>>> 
>>>>> On Jul 9, 2020, at 8:59 AM, Luigi Marongiu <marongiu.luigi using gmail.com> wrote:
>>>> 
>>>> Hello,
>>>> I have these vectors:
>>>> ```
>>>> X <- 1:7
>>>> Y <- c(1438443863, 3910100650, 10628760108, 28891979048, 78536576706,
>>>> 213484643920, 580311678200)
>>>> plot(Y~X)
>>>> ```
>>>> The y-axis starts at 0e0, but the first value is 1.4 billion. Why the
>>>> axis does not start at 1e9?
>>> 
>>> Because you're plotting on a linear, not log, scale, and 0*10^11 = 0.
>>> 
>>>> round(Y/1e11)
>>> [1] 0 0 0 0 1 2 6
>>> 
>>> Then try plot(log(Y) ~ X).
>>> 
>>> I hope this helps,
>>> John
>>> 
>>> -----------------------------
>>> John Fox, Professor Emeritus
>>> McMaster University
>>> Hamilton, Ontario, Canada
>>> Web: http::/socserv.mcmaster.ca/jfox
>>>> 
>>>> 
>>>> 
>>>> --
>>>> Best regards,
>>>> Luigi
>>>> 
>>>> ______________________________________________
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>>> 
>> 
>> 
>> -- 
>> Best regards,
>> Luigi
>> 
>> ______________________________________________
>> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
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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 using 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.