[R-sig-teaching] Plot f(x) = x^(1/5)

[Michael Weylandt]

Use the t-parametrized form from e.g.,
http://mathworld.wolfram.com/FoliumofDescartes.html

t <- seq(-50, 50, by=0.01)
x <- 3*t/(1+t^3)
y <- 3*t^2/(1+t^3)
plot(x, y, xlim=c(-5, 5), ylim=c(-5, 5), type="l")

(I'm limiting the plot to avoid the huge values that occur near t=-1)

MW

On Wed, May 18, 2016 at 1:58 PM, Steven Stoline <sstoline at gmail.com> wrote:
> Dear All:
>
>
> can someone please help me to plot the *Folium of Descrates:**  x^3+y^3=3xy
> for x<-seq(-5,5,0.010) and **y<-seq(-5,5,0.010) *
> <https://www.google.com/search?biw=1155&bih=597&q=R:+Folium+of+Descartes&spell=1&sa=X&ved=0ahUKEwiBrsnWpeTMAhUFKB4KHU5TD0EQvwUIGSgA>
>
>
> with thanks
> steve
>
> On Tue, May 17, 2016 at 9:07 AM, Gabor Grothendieck <ggrothendieck at gmail.com
>> wrote:
>
>> Try this:
>>
>>  y <- sign(x) * abs(x)^(1/5)
>>
>> On Tue, May 17, 2016 at 8:44 AM, Steven Stoline <sstoline at gmail.com>
>> wrote:
>> > Dear All:
>> >
>> >
>> > I am trying to plot the function f(x) = x^(1/5) for x=seq(-2,2,0.01). It
>> > give me only the plot of f(x) for the positive part of x. I checked the
>> > values of f(x), it is NaN for all negative values of x.
>> >
>> > *this is my code:*
>> >
>> >
>> > x<-seq(-2,2,0.01)
>> > y<- (x)^(1/5)
>> > plot(x,y, type="l", lwd=3, xlab = " ", ylab = " ", col="blue")
>> > abline(v=0, col="gray", lty=2, lwd=3)
>> > abline(h=0, col="gray", lty=2, lwd=3)
>> >
>> >
>> >
>> > any help will be appreciated.
>> >
>> >
>> > with many thanks
>> > steve
>> > --
>> > Steven M. Stoline
>> > 1123 Forest Avenue
>> > Portland, ME 04112
>> > sstoline at gmail.com
>> >
>> >         [[alternative HTML version deleted]]
>> >
>> > _______________________________________________
>> > R-sig-teaching at r-project.org mailing list
>> > https://stat.ethz.ch/mailman/listinfo/r-sig-teaching
>>
>>
>>
>> --
>> Statistics & Software Consulting
>> GKX Group, GKX Associates Inc.
>> tel: 1-877-GKX-GROUP
>> email: ggrothendieck at gmail.com
>>
>
>
>
> --
> Steven M. Stoline
> 1123 Forest Avenue
> Portland, ME 04112
> sstoline at gmail.com
>
>         [[alternative HTML version deleted]]
>
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