yes, this command finally gives me a plot in elliptic coordinates: draw(curve(sin(5t), t), t=0..2%pi, coordinates==elliptic(1.::DFLOAT))
thank you! ------- Original Message ------- On Monday, May 1st, 2023 at 3:10 PM, Waldek Hebisch <[email protected]> wrote: > On Mon, May 01, 2023 at 01:41:22PM +0000, '68th' via FriCAS - computer > algebra system wrote: > > > hello, > > > > i'm interested in defining equations for conic sections and plotting them > > in different coordinate systems. i was fine with online graphing > > calculators till i get to the elliptic coordinates, because the calculators > > only support Cartesian and polar ones. i found in the book 'The FriCAS > > System for Computer Mathematics' [7.2.7 Coordinate System Transformations] > > that FriCAS, which i've used some time ago to make and solve some > > equations, can plot in various coordinates, including elliptic. in 7.1.4 > > Two-Dimensional Options i found the following draw command: > > > > > draw(curve(sin(5t), t), t=0..2%pi, coordinates==polar) > > > > and it worked as expected, but when i replaced polar with elliptic i got: > > <snip> > > > i wrote to Ralf Hemmecke and he suggested the following command: > > > > > draw (f,0..%pi, 0..6, coordinates==elliptic(1.::DFLOAT)) > > > > i entered 'f=sin(5*t)' followed by the command and it gave me: > > > > > There are 7 exposed and 0 unexposed library operations named draw > > > 1. As Ralf wrote 'elliptic' needs a parameter. The following draws > something: > > draw(curve(sin(5t), t), t=0..2%pi, coordinates==elliptic(1.::DFLOAT)) > > 2. There are many forms of 'draw' command. Some take expressions > or similar and need name for parameter. Some take function > and do not need parameter name. There are separate forms for > curves ans surfeces, again both in version with parameters and > without. Form that Ralf gave is for drawing functions of two variables. > For curves is space one can use the following form: > > f1(t) == sin(5*t) > f2(t) == t > > c := curve(f1, f2)$ParametricPlaneCurve(SF -> SF) > > draw(c, 0..2*%pi, coordinates==elliptic(1.::DFLOAT)) > > 3. Note that in FriCAS '=' means equality or equation. Assignment > uses ':=', '==' defines functions. > > -- > Waldek Hebisch > > -- > You received this message because you are subscribed to the Google Groups > "FriCAS - computer algebra system" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/fricas-devel/20230501155312.jmp4xv5cglpojrkg%40fricas.math.uni.wroc.pl. -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/fricas-devel/4jQHCKTecARp_K58NUhLRH4MVHuBCrTgVebL8e5xxAHj21JYPJ0jR7J2sizNItsktvZU_GYgfyubRwz4XHraA5Mp8OzmAKBRuGFXnOcM0Fg%3D%40proton.me.
