Hot-keys on this page
r m x p toggle line displays
j k next/prev highlighted chunk
0 (zero) top of page
1 (one) first highlighted chunk
# -*- coding: utf-8 -*- """ Parametric Plots """ from __future__ import absolute_import
from .parametric_surface import ParametricSurface from .shapes2 import line3d from sage.arith.srange import xsrange, srange from sage.structure.element import is_Vector
from sage.ext.fast_eval import fast_float, fast_float_constant
def parametric_plot3d(f, urange, vrange=None, plot_points="automatic", boundary_style=None, **kwds): r""" Return a parametric three-dimensional space curve or surface.
There are four ways to call this function:
- ``parametric_plot3d([f_x, f_y, f_z], (u_min, u_max))``: `f_x, f_y, f_z` are three functions and `u_{\min}` and `u_{\max}` are real numbers
- ``parametric_plot3d([f_x, f_y, f_z], (u, u_min, u_max))``: `f_x, f_y, f_z` can be viewed as functions of `u`
- ``parametric_plot3d([f_x, f_y, f_z], (u_min, u_max), (v_min, v_max))``: `f_x, f_y, f_z` are each functions of two variables
- ``parametric_plot3d([f_x, f_y, f_z], (u, u_min, u_max), (v, v_min, v_max))``: `f_x, f_y, f_z` can be viewed as functions of `u` and `v`
INPUT:
- ``f`` - a 3-tuple of functions or expressions, or vector of size 3
- ``urange`` - a 2-tuple (u_min, u_max) or a 3-tuple (u, u_min, u_max)
- ``vrange`` - (optional - only used for surfaces) a 2-tuple (v_min, v_max) or a 3-tuple (v, v_min, v_max)
- ``plot_points`` - (default: "automatic", which is 75 for curves and [40,40] for surfaces) initial number of sample points in each parameter; an integer for a curve, and a pair of integers for a surface.
- ``boundary_style`` - (default: None, no boundary) a dict that describes how to draw the boundaries of regions by giving options that are passed to the line3d command.
- ``mesh`` - bool (default: False) whether to display mesh grid lines
- ``dots`` - bool (default: False) whether to display dots at mesh grid points
.. note::
#. By default for a curve any points where `f_x`, `f_y`, or `f_z` do not evaluate to a real number are skipped.
#. Currently for a surface `f_x`, `f_y`, and `f_z` have to be defined everywhere. This will change.
#. mesh and dots are not supported when using the Tachyon ray tracer renderer.
EXAMPLES: We demonstrate each of the four ways to call this function.
#. A space curve defined by three functions of 1 variable:
::
sage: parametric_plot3d((sin, cos, lambda u: u/10), (0,20)) Graphics3d Object
.. PLOT::
sphinx_plot(parametric_plot3d((sin, cos, lambda u: u/10), (0,20)))
Note above the lambda function, which creates a callable Python function that sends `u` to `u/10`.
#. Next we draw the same plot as above, but using symbolic functions:
::
sage: u = var('u') sage: parametric_plot3d((sin(u), cos(u), u/10), (u,0,20)) Graphics3d Object
.. PLOT::
u = var('u') sphinx_plot(parametric_plot3d((sin(u), cos(u), u/10), (u,0,20)))
#. We draw a parametric surface using 3 Python functions (defined using lambda):
::
sage: f = (lambda u,v: cos(u), lambda u,v: sin(u)+cos(v), lambda u,v: sin(v)) sage: parametric_plot3d(f, (0,2*pi), (-pi,pi)) Graphics3d Object
.. PLOT::
f = (lambda u,v: cos(u), lambda u,v: sin(u)+cos(v), lambda u,v: sin(v)) sphinx_plot(parametric_plot3d(f, (0,2*pi), (-pi,pi)))
#. The same surface, but where the defining functions are symbolic:
::
sage: u, v = var('u,v') sage: parametric_plot3d((cos(u), sin(u)+cos(v), sin(v)), (u,0,2*pi), (v,-pi,pi)) Graphics3d Object
.. PLOT::
u, v = var('u,v') sphinx_plot(parametric_plot3d((cos(u), sin(u)+cos(v) ,sin(v)), (u,0,2*pi), (v,-pi,pi)))
The surface, but with a mesh::
sage: u, v = var('u,v') sage: parametric_plot3d((cos(u), sin(u)+cos(v), sin(v)), (u,0,2*pi), (v,-pi,pi), mesh=True) Graphics3d Object
.. PLOT::
u, v = var('u,v') sphinx_plot(parametric_plot3d((cos(u), sin(u)+cos(v), sin(v)), (u,0,2*pi), (v,-pi,pi), mesh=True))
We increase the number of plot points, and make the surface green and transparent::
sage: parametric_plot3d((cos(u), sin(u)+cos(v), sin(v)), (u,0,2*pi), (v,-pi,pi), ....: color='green', opacity=0.1, plot_points=[30,30]) Graphics3d Object
.. PLOT::
u, v = var('u,v') sphinx_plot(parametric_plot3d((cos(u), sin(u)+cos(v), sin(v)), (u,0,2*pi), (v,-pi,pi), color='green', opacity=0.1, plot_points=[30,30]))
One can also color the surface using a coloring function and a colormap::
sage: u,v = var('u,v') sage: def cf(u,v): return sin(u+v/2)**2 sage: P = parametric_plot3d((cos(u), sin(u)+cos(v), sin(v)), ....: (u,0,2*pi), (v,-pi,pi), color=(cf,colormaps.PiYG), plot_points=[60,60]) sage: P.show(viewer='tachyon')
.. PLOT::
u,v = var('u,v') def cf(u,v): return sin(u+v/2)**2 P = parametric_plot3d((cos(u), sin(u)+cos(v), sin(v)), (u,0,2*pi), (v,-pi,pi), color=(cf,colormaps.PiYG), plot_points=[60,60]) sphinx_plot(P)
Another example, a colored Möbius band::
sage: cm = colormaps.ocean sage: def c(x,y): return sin(x*y)**2 sage: from sage.plot.plot3d.parametric_surface import MoebiusStrip sage: MoebiusStrip(5, 1, plot_points=200, color=(c,cm)) Graphics3d Object
.. PLOT::
cm = colormaps.ocean def c(x,y): return sin(x*y)**2 from sage.plot.plot3d.parametric_surface import MoebiusStrip sphinx_plot(MoebiusStrip(5, 1, plot_points=200, color=(c,cm)))
Yet another colored example::
sage: from sage.plot.plot3d.parametric_surface import ParametricSurface sage: cm = colormaps.autumn sage: def c(x,y): return sin(x*y)**2 sage: def g(x,y): return x, y+sin(y), x**2 + y**2 sage: ParametricSurface(g, (srange(-10,10,0.1), srange(-5,5.0,0.1)), color=(c,cm)) Graphics3d Object
.. PLOT::
from sage.plot.plot3d.parametric_surface import ParametricSurface cm = colormaps.autumn def c(x,y): return sin(x*y)**2 def g(x,y): return x, y+sin(y), x**2 + y**2 sphinx_plot(ParametricSurface(g, (srange(-10,10,0.1), srange(-5,5.0,0.1)), color=(c,cm)))
.. WARNING::
This kind of coloring using a colormap can be visualized using Jmol, Tachyon (option ``viewer='tachyon'``) and Canvas3D (option ``viewer='canvas3d'`` in the notebook).
We call the space curve function but with polynomials instead of symbolic variables.
::
sage: R.<t> = RDF[] sage: parametric_plot3d((t, t^2, t^3), (t,0,3)) Graphics3d Object
.. PLOT::
t = var('t') R = RDF['t'] sphinx_plot(parametric_plot3d((t, t**2, t**3), (t,0,3)))
Next we plot the same curve, but because we use (0, 3) instead of (t, 0, 3), each polynomial is viewed as a callable function of one variable::
sage: parametric_plot3d((t, t^2, t^3), (0,3)) Graphics3d Object
.. PLOT::
t = var('t') R = RDF['t'] sphinx_plot(parametric_plot3d((t, t**2, t**3), (0,3)))
We do a plot but mix a symbolic input, and an integer::
sage: t = var('t') sage: parametric_plot3d((1, sin(t), cos(t)), (t,0,3)) Graphics3d Object
.. PLOT::
t = var('t') sphinx_plot(parametric_plot3d((1, sin(t), cos(t)), (t,0,3)))
We specify a boundary style to show us the values of the function at its extrema::
sage: u, v = var('u,v') sage: parametric_plot3d((cos(u), sin(u)+cos(v), sin(v)), (u,0,pi), (v,0,pi), ....: boundary_style={"color": "black", "thickness": 2}) Graphics3d Object
.. PLOT::
u, v = var('u,v') P = parametric_plot3d((cos(u), sin(u)+cos(v), sin(v)), (u,0,pi), (v,0,pi), boundary_style={"color":"black", "thickness":2}) sphinx_plot(P)
We can plot vectors::
sage: x,y = var('x,y') sage: parametric_plot3d(vector([x-y, x*y, x*cos(y)]), (x,0,2), (y,0,2)) Graphics3d Object
.. PLOT::
x,y = var('x,y') sphinx_plot(parametric_plot3d(vector([x-y, x*y, x*cos(y)]), (x,0,2), (y,0,2)))
::
sage: t = var('t') sage: p = vector([1,2,3]) sage: q = vector([2,-1,2]) sage: parametric_plot3d(p*t+q, (t,0,2)) Graphics3d Object
.. PLOT::
t = var('t') p = vector([1,2,3]) q = vector([2,-1,2]) sphinx_plot(parametric_plot3d(p*t+q, (t,0,2)))
Any options you would normally use to specify the appearance of a curve are valid as entries in the ``boundary_style`` dict.
MANY MORE EXAMPLES:
We plot two interlinked tori::
sage: u, v = var('u,v') sage: f1 = (4+(3+cos(v))*sin(u), 4+(3+cos(v))*cos(u), 4+sin(v)) sage: f2 = (8+(3+cos(v))*cos(u), 3+sin(v), 4+(3+cos(v))*sin(u)) sage: p1 = parametric_plot3d(f1, (u,0,2*pi), (v,0,2*pi), texture="red") sage: p2 = parametric_plot3d(f2, (u,0,2*pi), (v,0,2*pi), texture="blue") sage: p1 + p2 Graphics3d Object
.. PLOT::
u, v = var('u,v') f1 = (4+(3+cos(v))*sin(u), 4+(3+cos(v))*cos(u), 4+sin(v)) f2 = (8+(3+cos(v))*cos(u), 3+sin(v), 4+(3+cos(v))*sin(u)) p1 = parametric_plot3d(f1, (u,0,2*pi), (v,0,2*pi), texture="red") p2 = parametric_plot3d(f2, (u,0,2*pi), (v,0,2*pi), texture="blue") sphinx_plot(p1 + p2)
A cylindrical Star of David::
sage: u,v = var('u v') sage: K = (abs(cos(u))^200+abs(sin(u))^200)^(-1.0/200) sage: f_x = cos(u) * cos(v) * (abs(cos(3*v/4))^500+abs(sin(3*v/4))^500)^(-1/260) * K sage: f_y = cos(u) * sin(v) * (abs(cos(3*v/4))^500+abs(sin(3*v/4))^500)^(-1/260) * K sage: f_z = sin(u) * K sage: parametric_plot3d([f_x, f_y, f_z], (u, -pi, pi), (v, 0, 2*pi)) Graphics3d Object
.. PLOT::
u,v = var('u v') K = (abs(cos(u))**200+abs(sin(u))**200)**(-1.0/200) f_x = cos(u) * cos(v) * (abs(cos(0.75*v))**500+abs(sin(0.75*v))**500)**(-1.0/260) * K f_y = cos(u)*sin(v)*(abs(cos(0.75*v))**500+abs(sin(0.75*v))**500)**(-1.0/260) * K f_z = sin(u) * K P = parametric_plot3d([f_x, f_y, f_z], (u, -pi, pi), (v, 0, 2*pi)) sphinx_plot(P)
Double heart::
sage: u, v = var('u,v') sage: G1 = abs(sqrt(2)*tanh((u/sqrt(2)))) sage: G2 = abs(sqrt(2)*tanh((v/sqrt(2)))) sage: f_x = (abs(v) - abs(u) - G1 + G2)*sin(v) sage: f_y = (abs(v) - abs(u) - G1 - G2)*cos(v) sage: f_z = sin(u)*(abs(cos(u)) + abs(sin(u)))^(-1) sage: parametric_plot3d([f_x, f_y, f_z], (u,0,pi), (v,-pi,pi)) Graphics3d Object
.. PLOT::
u, v = var('u,v') G1 = abs(sqrt(2)*tanh((u/sqrt(2)))) G2 = abs(sqrt(2)*tanh((v/sqrt(2)))) f_x = (abs(v) - abs(u) - G1 + G2)*sin(v) f_y = (abs(v) - abs(u) - G1 - G2)*cos(v) f_z = sin(u)*(abs(cos(u)) + abs(sin(u)))**(-1) sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,0,pi), (v,-pi,pi)))
Heart::
sage: u, v = var('u,v') sage: f_x = cos(u)*(4*sqrt(1-v^2)*sin(abs(u))^abs(u)) sage: f_y = sin(u)*(4*sqrt(1-v^2)*sin(abs(u))^abs(u)) sage: f_z = v sage: parametric_plot3d([f_x, f_y, f_z], (u,-pi,pi), (v,-1,1), frame=False, color="red") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = cos(u)*(4*sqrt(1-v**2)*sin(abs(u))**abs(u)) f_y = sin(u) *(4*sqrt(1-v**2)*sin(abs(u))**abs(u)) f_z = v sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,-pi,pi), (v,-1,1), frame=False, color="red"))
A Trefoil knot (:wikipedia:`Trefoil_knot`)::
sage: u, v = var('u,v') sage: f_x = (4*(1+0.25*sin(3*v))+cos(u))*cos(2*v) sage: f_y = (4*(1+0.25*sin(3*v))+cos(u))*sin(2*v) sage: f_z = sin(u)+2*cos(3*v) sage: parametric_plot3d([f_x, f_y, f_z], (u,-pi,pi), (v,-pi,pi), frame=False, color="blue") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = (4*(1+0.25*sin(3*v))+cos(u))*cos(2*v) f_y = (4*(1+0.25*sin(3*v))+cos(u))*sin(2*v) f_z = sin(u)+2*cos(3*v) sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,-pi,pi), (v,-pi,pi), frame=False, color="blue"))
Green bowtie::
sage: u, v = var('u,v') sage: f_x = sin(u) / (sqrt(2) + sin(v)) sage: f_y = sin(u) / (sqrt(2) + cos(v)) sage: f_z = cos(u) / (1 + sqrt(2)) sage: parametric_plot3d([f_x, f_y, f_z], (u,-pi,pi), (v,-pi,pi), frame=False, color="green") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = sin(u) / (sqrt(2) + sin(v)) f_y = sin(u) / (sqrt(2) + cos(v)) f_z = cos(u) / (1 + sqrt(2)) sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,-pi,pi), (v,-pi,pi), frame=False, color="green"))
Boy's surface (:wikipedia:`Boy's_surface` and https://mathcurve.com/surfaces/boy/boy.shtml)::
sage: u, v = var('u,v') sage: K = cos(u) / (sqrt(2) - cos(2*u)*sin(3*v)) sage: f_x = K * (cos(u)*cos(2*v)+sqrt(2)*sin(u)*cos(v)) sage: f_y = K * (cos(u)*sin(2*v)-sqrt(2)*sin(u)*sin(v)) sage: f_z = 3 * K * cos(u) sage: parametric_plot3d([f_x, f_y, f_z], (u,-2*pi,2*pi), (v,0,pi), ....: plot_points=[90,90], frame=False, color="orange") # long time -- about 30 seconds Graphics3d Object
.. PLOT::
u, v = var('u,v') K = cos(u) / (sqrt(2) - cos(2*u)*sin(3*v)) f_x = K * (cos(u)*cos(2*v)+sqrt(2)*sin(u)*cos(v)) f_y = K * (cos(u)*sin(2*v)-sqrt(2)*sin(u)*sin(v)) f_z = 3 * K * cos(u) P = parametric_plot3d([f_x, f_y, f_z], (u,-2*pi,2*pi), (v,0,pi), plot_points=[90,90], frame=False, color="orange") # long time -- about 30 seconds sphinx_plot(P)
Maeder's Owl also known as Bour's minimal surface (:wikipedia:`Bour%27s_minimal_surface`)::
sage: u, v = var('u,v') sage: f_x = v*cos(u) - 0.5*v^2*cos(2*u) sage: f_y = -v*sin(u) - 0.5*v^2*sin(2*u) sage: f_z = 4 * v^1.5 * cos(3*u/2) / 3 sage: parametric_plot3d([f_x, f_y, f_z], (u,-2*pi,2*pi), (v,0,1), ....: plot_points=[90,90], frame=False, color="purple") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = v*cos(u) - 0.5*v**2*cos(2*u) f_y = -v*sin(u) - 0.5*v**2*sin(2*u) f_z = 4 * v**1.5 * cos(3*u/2) / 3 P = parametric_plot3d([f_x, f_y, f_z], (u,-2*pi,2*pi), (v,0,1), plot_points=[90,90], frame=False, color="purple") sphinx_plot(P)
Bracelet::
sage: u, v = var('u,v') sage: f_x = (2 + 0.2*sin(2*pi*u))*sin(pi*v) sage: f_y = 0.2 * cos(2*pi*u) * 3 * cos(2*pi*v) sage: f_z = (2 + 0.2*sin(2*pi*u))*cos(pi*v) sage: parametric_plot3d([f_x, f_y, f_z], (u,0,pi/2), (v,0,3*pi/4), frame=False, color="gray") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = (2 + 0.2*sin(2*pi*u))*sin(pi*v) f_y = 0.2 * cos(2*pi*u) * 3* cos(2*pi*v) f_z = (2 + 0.2*sin(2*pi*u))*cos(pi*v) P = parametric_plot3d([f_x, f_y, f_z], (u,0,pi/2), (v,0,3*pi/4), frame=False, color="gray") sphinx_plot(P)
Green goblet::
sage: u, v = var('u,v') sage: f_x = cos(u) * cos(2*v) sage: f_y = sin(u) * cos(2*v) sage: f_z = sin(v) sage: parametric_plot3d([f_x, f_y, f_z], (u,0,2*pi), (v,0,pi), frame=False, color="green") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = cos(u) * cos(2*v) f_y = sin(u) * cos(2*v) f_z = sin(v) sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,0,2*pi), (v,0,pi), frame=False, color="green"))
Funny folded surface - with square projection::
sage: u, v = var('u,v') sage: f_x = cos(u) * sin(2*v) sage: f_y = sin(u) * cos(2*v) sage: f_z = sin(v) sage: parametric_plot3d([f_x, f_y, f_z], (u,0,2*pi), (v,0,2*pi), frame=False, color="green") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = cos(u) * sin(2*v) f_y = sin(u) * cos(2*v) f_z = sin(v) sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,0,2*pi), (v,0,2*pi), frame=False, color="green"))
Surface of revolution of figure 8::
sage: u, v = var('u,v') sage: f_x = cos(u) * sin(2*v) sage: f_y = sin(u) * sin(2*v) sage: f_z = sin(v) sage: parametric_plot3d([f_x, f_y, f_z], (u,0,2*pi), (v,0,2*pi), frame=False, color="green") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = cos(u) * sin(2*v) f_y = sin(u) * sin(2*v) f_z = sin(v) sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,0,2*pi), (v,0,2*pi), frame=False, color="green"))
Yellow Whitney's umbrella (:wikipedia:`Whitney_umbrella`)::
sage: u, v = var('u,v') sage: f_x = u*v sage: f_y = u sage: f_z = v^2 sage: parametric_plot3d([f_x, f_y, f_z], (u,-1,1), (v,-1,1), frame=False, color="yellow") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = u*v f_y = u f_z = v**2 sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,-1,1), (v,-1,1), frame=False, color="yellow"))
Cross cap (:wikipedia:`Cross-cap`)::
sage: u, v = var('u,v') sage: f_x = (1+cos(v)) * cos(u) sage: f_y = (1+cos(v)) * sin(u) sage: f_z = -tanh((2/3)*(u-pi)) * sin(v) sage: parametric_plot3d([f_x, f_y, f_z], (u,0,2*pi), (v,0,2*pi), frame=False, color="red") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = (1+cos(v)) * cos(u) f_y = (1+cos(v)) * sin(u) f_z = -tanh((2.0/3.0)*(u-pi)) * sin(v) sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,0,2*pi), (v,0,2*pi), frame=False, color="red"))
Twisted torus::
sage: u, v = var('u,v') sage: f_x = (3+sin(v)+cos(u)) * cos(2*v) sage: f_y = (3+sin(v)+cos(u)) * sin(2*v) sage: f_z = sin(u) + 2*cos(v) sage: parametric_plot3d([f_x, f_y, f_z], (u,0,2*pi), (v,0,2*pi), frame=False, color="red") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = (3+sin(v)+cos(u)) * cos(2*v) f_y = (3+sin(v)+cos(u)) * sin(2*v) f_z = sin(u) + 2*cos(v) sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,0,2*pi), (v,0,2*pi), frame=False, color="red"))
Four intersecting discs::
sage: u, v = var('u,v') sage: f_x = v*cos(u) - 0.5*v^2*cos(2*u) sage: f_y = -v*sin(u) - 0.5*v^2*sin(2*u) sage: f_z = 4 * v^1.5 * cos(3*u/2) / 3 sage: parametric_plot3d([f_x, f_y, f_z], (u,0,4*pi), (v,0,2*pi), frame=False, color="red", opacity=0.7) Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = v*cos(u) - 0.5*v**2*cos(2*u) f_y = -v*sin(u) - 0.5*v**2*sin(2*u) f_z = 4 * v**1.5 * cos(3.0*u/2.0) /3 sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,0,4*pi), (v,0,2*pi), frame=False, color="red", opacity=0.7))
Steiner surface/Roman's surface (see :wikipedia:`Roman_surface` and :wikipedia:`Steiner_surface`)::
sage: u, v = var('u,v') sage: f_x = (sin(2*u) * cos(v) * cos(v)) sage: f_y = (sin(u) * sin(2*v)) sage: f_z = (cos(u) * sin(2*v)) sage: parametric_plot3d([f_x, f_y, f_z], (u,-pi/2,pi/2), (v,-pi/2,pi/2), frame=False, color="red") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = (sin(2*u) * cos(v) * cos(v)) f_y = (sin(u) * sin(2*v)) f_z = (cos(u) * sin(2*v)) sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,-pi/2,pi/2), (v,-pi/2,pi/2), frame=False, color="red"))
Klein bottle? (see :wikipedia:`Klein_bottle`)::
sage: u, v = var('u,v') sage: f_x = (3*(1+sin(v)) + 2*(1-cos(v)/2)*cos(u)) * cos(v) sage: f_y = (4+2*(1-cos(v)/2)*cos(u)) * sin(v) sage: f_z = -2 * (1-cos(v)/2) * sin(u) sage: parametric_plot3d([f_x, f_y, f_z], (u,0,2*pi), (v,0,2*pi), frame=False, color="green") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = (3*(1+sin(v)) + 2*(1-cos(v)/2)*cos(u)) * cos(v) f_y = (4+2*(1-cos(v)/2)*cos(u)) * sin(v) f_z = -2 * (1-cos(v)/2) * sin(u) sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,0,2*pi), (v,0,2*pi), frame=False, color="green"))
A Figure 8 embedding of the Klein bottle (see :wikipedia:`Klein_bottle`)::
sage: u, v = var('u,v') sage: f_x = (2+cos(v/2)*sin(u)-sin(v/2)*sin(2*u)) * cos(v) sage: f_y = (2+cos(v/2)*sin(u)-sin(v/2)*sin(2*u)) * sin(v) sage: f_z = sin(v/2)*sin(u) + cos(v/2)*sin(2*u) sage: parametric_plot3d([f_x, f_y, f_z], (u,0,2*pi), (v,0,2*pi), frame=False, color="red") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = (2+cos(0.5*v)*sin(u)-sin(0.5*v)*sin(2*u)) * cos(v) f_y = (2+cos(0.5*v)*sin(u)-sin(0.5*v)*sin(2*u)) * sin(v) f_z = sin(v*0.5)*sin(u) + cos(v*0.5)*sin(2*u) sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,0,2*pi), (v,0,2*pi), frame=False, color="red"))
Enneper's surface (see :wikipedia:`Enneper_surface`)::
sage: u, v = var('u,v') sage: f_x = u - u^3/3 + u*v^2 sage: f_y = v - v^3/3 + v*u^2 sage: f_z = u^2 - v^2 sage: parametric_plot3d([f_x, f_y, f_z], (u,-2,2), (v,-2,2), frame=False, color="red") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = u - u**3/3 + u*v**2 f_y = v - v**3/3 + v*u**2 f_z = u**2 - v**2 sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,-2,2), (v,-2,2), frame=False, color="red"))
Henneberg's surface (see http://xahlee.org/surface/gallery_m.html)::
sage: u, v = var('u,v') sage: f_x = 2*sinh(u)*cos(v) - (2/3)*sinh(3*u)*cos(3*v) sage: f_y = 2*sinh(u)*sin(v) + (2/3)*sinh(3*u)*sin(3*v) sage: f_z = 2 * cosh(2*u) * cos(2*v) sage: parametric_plot3d([f_x, f_y, f_z], (u,-1,1), (v,-pi/2,pi/2), frame=False, color="red") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = 2.0*sinh(u)*cos(v) - (2.0/3.0)*sinh(3*u)*cos(3*v) f_y = 2.0*sinh(u)*sin(v) + (2.0/3.0)*sinh(3*u)*sin(3*v) f_z = 2.0 * cosh(2*u) * cos(2*v) sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,-1,1), (v,-pi/2,pi/2), frame=False, color="red"))
Dini's spiral::
sage: u, v = var('u,v') sage: f_x = cos(u) * sin(v) sage: f_y = sin(u) * sin(v) sage: f_z = (cos(v)+log(tan(v/2))) + 0.2*u sage: parametric_plot3d([f_x, f_y, f_z], (u,0,12.4), (v,0.1,2), frame=False, color="red") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = cos(u) * sin(v) f_y = sin(u) * sin(v) f_z = (cos(v)+log(tan(v*0.5))) + 0.2*u sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,0,12.4), (v,0.1,2), frame=False, color="red"))
Catalan's surface (see http://xahlee.org/surface/catalan/catalan.html)::
sage: u, v = var('u,v') sage: f_x = u - sin(u)*cosh(v) sage: f_y = 1 - cos(u)*cosh(v) sage: f_z = 4 * sin(1/2*u) * sinh(v/2) sage: parametric_plot3d([f_x, f_y, f_z], (u,-pi,3*pi), (v,-2,2), frame=False, color="red") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = u - sin(u)*cosh(v) f_y = 1.0 - cos(u)*cosh(v) f_z = 4.0 * sin(0.5*u) * sinh(0.5*v) sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,-pi,3*pi), (v,-2,2), frame=False, color="red"))
A Conchoid::
sage: u, v = var('u,v') sage: k = 1.2; k_2 = 1.2; a = 1.5 sage: f = (k^u*(1+cos(v))*cos(u), k^u*(1+cos(v))*sin(u), k^u*sin(v)-a*k_2^u) sage: parametric_plot3d(f, (u,0,6*pi), (v,0,2*pi), plot_points=[40,40], texture=(0,0.5,0)) Graphics3d Object
.. PLOT::
u, v = var('u,v') k = 1.2; k_2 = 1.2; a = 1.5 f = (k**u*(1+cos(v))*cos(u), k**u*(1+cos(v))*sin(u), k**u*sin(v)-a*k_2**u) sphinx_plot(parametric_plot3d(f, (u,0,6*pi), (v,0,2*pi), plot_points=[40,40], texture=(0,0.5,0)))
A Möbius strip::
sage: u,v = var("u,v") sage: parametric_plot3d([cos(u)*(1+v*cos(u/2)), sin(u)*(1+v*cos(u/2)), 0.2*v*sin(u/2)], ....: (u,0, 4*pi+0.5), (v,0, 0.3), plot_points=[50,50]) Graphics3d Object
.. PLOT::
u,v = var("u,v") sphinx_plot(parametric_plot3d([cos(u)*(1+v*cos(u*0.5)), sin(u)*(1+v*cos(u*0.5)), 0.2*v*sin(u*0.5)], (u,0,4*pi+0.5), (v,0,0.3), plot_points=[50,50]))
A Twisted Ribbon::
sage: u, v = var('u,v') sage: parametric_plot3d([3*sin(u)*cos(v), 3*sin(u)*sin(v), cos(v)], ....: (u,0,2*pi), (v,0,pi), plot_points=[50,50]) Graphics3d Object
.. PLOT::
u, v = var('u,v') sphinx_plot(parametric_plot3d([3*sin(u)*cos(v), 3*sin(u)*sin(v), cos(v)], (u,0,2*pi), (v,0,pi), plot_points=[50,50]))
An Ellipsoid::
sage: u, v = var('u,v') sage: parametric_plot3d([3*sin(u)*cos(v), 2*sin(u)*sin(v), cos(u)], ....: (u,0, 2*pi), (v, 0, 2*pi), plot_points=[50,50], aspect_ratio=[1,1,1]) Graphics3d Object
.. PLOT::
u, v = var('u,v') sphinx_plot(parametric_plot3d([3*sin(u)*cos(v), 2*sin(u)*sin(v), cos(u)], (u,0,2*pi), (v,0,2*pi), plot_points=[50,50], aspect_ratio=[1,1,1]))
A Cone::
sage: u, v = var('u,v') sage: parametric_plot3d([u*cos(v), u*sin(v), u], (u,-1,1), (v,0,2*pi+0.5), plot_points=[50,50]) Graphics3d Object
.. PLOT::
u, v = var('u,v') sphinx_plot(parametric_plot3d([u*cos(v), u*sin(v), u], (u,-1,1), (v,0,2*pi+0.5), plot_points=[50,50]))
A Paraboloid::
sage: u, v = var('u,v') sage: parametric_plot3d([u*cos(v), u*sin(v), u^2], (u,0,1), (v,0,2*pi+0.4), plot_points=[50,50]) Graphics3d Object
.. PLOT::
u, v = var('u,v') sphinx_plot(parametric_plot3d([u*cos(v), u*sin(v), u**2], (u,0,1), (v,0,2*pi+0.4), plot_points=[50,50]))
A Hyperboloid::
sage: u, v = var('u,v') sage: plot3d(u^2-v^2, (u,-1,1), (v,-1,1), plot_points=[50,50]) Graphics3d Object
.. PLOT::
u, v = var('u,v') sphinx_plot(plot3d(u**2-v**2, (u,-1,1), (v,-1,1), plot_points=[50,50]))
A weird looking surface - like a Möbius band but also an O::
sage: u, v = var('u,v') sage: parametric_plot3d([sin(u)*cos(u)*log(u^2)*sin(v), (u^2)^(1/6)*(cos(u)^2)^(1/4)*cos(v), sin(v)], ....: (u,0.001,1), (v,-pi,pi+0.2), plot_points=[50,50]) Graphics3d Object
.. PLOT::
u, v = var('u,v') sphinx_plot(parametric_plot3d([sin(u)*cos(u)*log(u**2)*sin(v), (u**2)**(1.0/6.0)*(cos(u)**2)**(0.25)*cos(v), sin(v)], (u,0.001,1), (v,-pi,pi+0.2), plot_points=[50,50]))
A heart, but not a cardioid (for my wife)::
sage: u, v = var('u,v') sage: p1 = parametric_plot3d([sin(u)*cos(u)*log(u^2)*v*(1-v)/2, ((u^6)^(1/20)*(cos(u)^2)^(1/4)-1/2)*v*(1-v), v^(0.5)], ....: (u,0.001,1), (v,0,1), plot_points=[70,70], color='red') sage: p2 = parametric_plot3d([-sin(u)*cos(u)*log(u^2)*v*(1-v)/2, ((u^6)^(1/20)*(cos(u)^2)^(1/4)-1/2)*v*(1-v), v^(0.5)], ....: (u, 0.001,1), (v,0,1), plot_points=[70,70], color='red') sage: show(p1+p2)
.. PLOT::
u, v = var('u,v') p1 = parametric_plot3d([sin(u)*cos(u)*log(u**2)*v*(1-v)*0.5, ((u**6)**(1/20.0)*(cos(u)**2)**(0.25)-0.5)*v*(1-v), v**(0.5)], (u,0.001,1), (v,0,1), plot_points=[70,70], color='red') p2 = parametric_plot3d([-sin(u)*cos(u)*log(u**2)*v*(1-v)*0.5, ((u**6)**(1/20.0)*(cos(u)**2)**(0.25)-0.5)*v*(1-v), v**(0.5)], (u,0.001,1), (v,0,1), plot_points=[70,70], color='red') sphinx_plot(p1+p2)
A Hyperhelicoidal::
sage: u = var("u") sage: v = var("v") sage: f_x = (sinh(v)*cos(3*u)) / (1+cosh(u)*cosh(v)) sage: f_y = (sinh(v)*sin(3*u)) / (1+cosh(u)*cosh(v)) sage: f_z = (cosh(v)*sinh(u)) / (1+cosh(u)*cosh(v)) sage: parametric_plot3d([f_x, f_y, f_z], (u,-pi,pi), (v,-pi,pi), plot_points=[50,50], frame=False, color="red") Graphics3d Object
.. PLOT::
u = var("u") v = var("v") f_x = (sinh(v)*cos(3*u)) / (1+cosh(u)*cosh(v)) f_y = (sinh(v)*sin(3*u)) / (1+cosh(u)*cosh(v)) f_z = (cosh(v)*sinh(u)) / (1+cosh(u)*cosh(v)) sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,-pi,pi), (v,-pi,pi), plot_points=[50,50], frame=False, color="red"))
A Helicoid (lines through a helix, :wikipedia:`Helix`)::
sage: u, v = var('u,v') sage: f_x = sinh(v) * sin(u) sage: f_y = -sinh(v) * cos(u) sage: f_z = 3 * u sage: parametric_plot3d([f_x, f_y, f_z], (u,-pi,pi), (v,-pi,pi), plot_points=[50,50], frame=False, color="red") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = sinh(v) * sin(u) f_y = -sinh(v) * cos(u) f_z = 3 * u sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,-pi,pi), (v,-pi,pi), plot_points=[50,50], frame=False, color="red"))
Kuen's surface (http://virtualmathmuseum.org/Surface/kuen/kuen.html)::
sage: f_x = (2*(cos(u) + u*sin(u))*sin(v))/(1+ u^2*sin(v)^2) sage: f_y = (2*(sin(u) - u*cos(u))*sin(v))/(1+ u^2*sin(v)^2) sage: f_z = log(tan(1/2 *v)) + (2*cos(v))/(1+ u^2*sin(v)^2) sage: parametric_plot3d([f_x, f_y, f_z], (u,0,2*pi), (v,0.01,pi-0.01), plot_points=[50,50], frame=False, color="green") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = (2.0*(cos(u)+u*sin(u))*sin(v)) / (1.0+u**2*sin(v)**2) f_y = (2.0*(sin(u)-u*cos(u))*sin(v)) / (1.0+u**2*sin(v)**2) f_z = log(tan(0.5 *v)) + (2*cos(v))/(1.0+u**2*sin(v)**2) sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,0,2*pi), (v,0.01,pi-0.01), plot_points=[50,50], frame=False, color="green"))
A 5-pointed star::
sage: G1 = (abs(cos(u/4))^0.5+abs(sin(u/4))^0.5)^(-1/0.3) sage: G2 = (abs(cos(5*v/4))^1.7+abs(sin(5*v/4))^1.7)^(-1/0.1) sage: f_x = cos(u) * cos(v) * G1 * G2 sage: f_y = cos(u) * sin(v) * G1 * G2 sage: f_z = sin(u) * G1 sage: parametric_plot3d([f_x, f_y, f_z], (u,-pi/2,pi/2), (v,0,2*pi), plot_points=[50,50], frame=False, color="green") Graphics3d Object
.. PLOT::
u, v = var('u,v') G1 = (abs(cos(u/4))**0.5+abs(sin(u/4))**0.5)**(-1/0.3) G2 = (abs(cos(5*v/4))**1.7+abs(sin(5*v/4))**1.7)**(-1/0.1) f_x = cos(u) * cos(v) * G1 * G2 f_y = cos(u) * sin(v) * G1 * G2 f_z = sin(u) * G1 sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,-pi/2,pi/2), (v,0,2*pi), plot_points=[50,50], frame=False, color="green"))
A cool self-intersecting surface (Eppener surface?)::
sage: f_x = u - u^3/3 + u*v^2 sage: f_y = v - v^3/3 + v*u^2 sage: f_z = u^2 - v^2 sage: parametric_plot3d([f_x, f_y, f_z], (u,-25,25), (v,-25,25), plot_points=[50,50], frame=False, color="green") Graphics3d Object
.. PLOT::
u, v = var('u,v') f_x = u - u**3/3 + u*v**2 f_y = v - v**3/3 + v*u**2 f_z = u**2 - v**2 sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,-25,25), (v,-25,25), plot_points=[50,50], frame=False, color="green"))
The breather surface (:wikipedia:`Breather_surface`)::
sage: K = sqrt(0.84) sage: G = (0.4*((K*cosh(0.4*u))^2 + (0.4*sin(K*v))^2)) sage: f_x = (2*K*cosh(0.4*u)*(-(K*cos(v)*cos(K*v)) - sin(v)*sin(K*v)))/G sage: f_y = (2*K*cosh(0.4*u)*(-(K*sin(v)*cos(K*v)) + cos(v)*sin(K*v)))/G sage: f_z = -u + (2*0.84*cosh(0.4*u)*sinh(0.4*u))/G sage: parametric_plot3d([f_x, f_y, f_z], (u,-13.2,13.2), (v,-37.4,37.4), plot_points=[90,90], frame=False, color="green") Graphics3d Object
.. PLOT::
u, v = var('u,v') K = sqrt(0.84) G = (0.4*((K*cosh(0.4*u))**2 + (0.4*sin(K*v))**2)) f_x = (2*K*cosh(0.4*u)*(-(K*cos(v)*cos(K*v)) - sin(v)*sin(K*v)))/G f_y = (2*K*cosh(0.4*u)*(-(K*sin(v)*cos(K*v)) + cos(v)*sin(K*v)))/G f_z = -u + (2*0.84*cosh(0.4*u)*sinh(0.4*u))/G sphinx_plot(parametric_plot3d([f_x, f_y, f_z], (u,-13.2,13.2), (v,-37.4,37.4), plot_points=[90,90], frame=False, color="green"))
TESTS::
sage: u, v = var('u,v') sage: plot3d(u^2-v^2, (u,-1,1), (u,-1,1)) Traceback (most recent call last): ... ValueError: range variables should be distinct, but there are duplicates
From :trac:`2858`::
sage: parametric_plot3d((u,-u,v), (u,-10,10),(v,-10,10)) Graphics3d Object sage: f(u)=u; g(v)=v^2; parametric_plot3d((g,f,f), (-10,10),(-10,10)) Graphics3d Object
From :trac:`5368`::
sage: x, y = var('x,y') sage: plot3d(x*y^2 - sin(x), (x,-1,1), (y,-1,1)) Graphics3d Object
""" # TODO: # * Surface -- behavior of functions not defined everywhere -- see note above # * Iterative refinement
# color_function -- (default: "automatic") how to determine the color of curves and surfaces # color_function_scaling -- (default: True) whether to scale the input to color_function # exclusions -- (default: "automatic") u points or (u,v) conditions to exclude. # (E.g., exclusions could be a function e = lambda u, v: False if u < v else True # exclusions_style -- (default: None) what to draw at excluded points # max_recursion -- (default: "automatic") maximum number of recursive subdivisions, # when ... # mesh -- (default: "automatic") how many mesh divisions in each direction to draw # mesh_functions -- (default: "automatic") how to determine the placement of mesh divisions # mesh_shading -- (default: None) how to shade regions between mesh divisions # plot_range -- (default: "automatic") range of values to include
return sum([parametric_plot3d(v, urange, vrange, plot_points=plot_points, **kwds) for v in f])
raise ValueError("f must be a list, tuple, or vector of length 3")
else:
def _parametric_plot3d_curve(f, urange, plot_points, **kwds): r""" Return a parametric three-dimensional space curve. This function is used internally by the :func:`parametric_plot3d` command.
There are two ways this function is invoked by :func:`parametric_plot3d`.
- ``parametric_plot3d([f_x, f_y, f_z], (u_min, u_max))``: `f_x, f_y, f_z` are three functions and `u_{\min}` and `u_{\max}` are real numbers
- ``parametric_plot3d([f_x, f_y, f_z], (u, u_min, u_max))``: `f_x, f_y, f_z` can be viewed as functions of `u`
INPUT:
- ``f`` - a 3-tuple of functions or expressions, or vector of size 3
- ``urange`` - a 2-tuple (u_min, u_max) or a 3-tuple (u, u_min, u_max)
- ``plot_points`` - (default: "automatic", which is 75) initial number of sample points in each parameter; an integer.
EXAMPLES:
We demonstrate each of the two ways of calling this. See :func:`parametric_plot3d` for many more examples.
We do the first one with a lambda function, which creates a callable Python function that sends `u` to `u/10`::
sage: parametric_plot3d((sin, cos, lambda u: u/10), (0,20)) # indirect doctest Graphics3d Object
Now we do the same thing with symbolic expressions::
sage: u = var('u') sage: parametric_plot3d((sin(u), cos(u), u/10), (u,0,20)) Graphics3d Object
"""
def _parametric_plot3d_surface(f, urange, vrange, plot_points, boundary_style, **kwds): r""" Return a parametric three-dimensional space surface. This function is used internally by the :func:`parametric_plot3d` command.
There are two ways this function is invoked by :func:`parametric_plot3d`.
- ``parametric_plot3d([f_x, f_y, f_z], (u_min, u_max), (v_min, v_max))``: `f_x, f_y, f_z` are each functions of two variables
- ``parametric_plot3d([f_x, f_y, f_z], (u, u_min, u_max), (v, v_min, v_max))``: `f_x, f_y, f_z` can be viewed as functions of `u` and `v`
INPUT:
- ``f`` - a 3-tuple of functions or expressions, or vector of size 3
- ``urange`` - a 2-tuple (u_min, u_max) or a 3-tuple (u, u_min, u_max)
- ``vrange`` - a 2-tuple (v_min, v_max) or a 3-tuple (v, v_min, v_max)
- ``plot_points`` - (default: "automatic", which is [40,40] for surfaces) initial number of sample points in each parameter; a pair of integers.
- ``boundary_style`` - (default: None, no boundary) a dict that describes how to draw the boundaries of regions by giving options that are passed to the line3d command.
EXAMPLES:
We demonstrate each of the two ways of calling this. See :func:`parametric_plot3d` for many more examples.
We do the first one with lambda functions::
sage: f = (lambda u,v: cos(u), lambda u,v: sin(u)+cos(v), lambda u,v: sin(v)) sage: parametric_plot3d(f, (0, 2*pi), (-pi, pi)) # indirect doctest Graphics3d Object
Now we do the same thing with symbolic expressions::
sage: u, v = var('u,v') sage: parametric_plot3d((cos(u), sin(u) + cos(v), sin(v)), (u, 0, 2*pi), (v, -pi, pi), mesh=True) Graphics3d Object """
|