File:Poincare-sphere arrows.svg
Summary
| Description |
English: Drawing of a Poincaré sphere, which illustrates the space of possible polarisations of electromagnetic waves. The sphere is drawn with three great circles, labels for six basic polarisations H (linear horizontal), V (linear vertical), D (linear diagonal), A (linear antidiagonal), R (right-hand circular) and L (left-hand circular) and images of the polarisation vectors for each. Additionally the coordinate system of Stokes vectors with components S₁, S₂ and S₃ is drawn in the center of the sphere.
Deutsch: Zeichnung einer Poincaré-Kugel, die den Raum der möglichen Polarisationen elektromagnetischer Wellen darstellt. Die Kugel ist mit drei Großkreisen gezeichnet, Zeichen für die sechs Basispolarisationen H (linear horizontal), V (linear vertikal), D (linear diagonal), A (linear antidiagonal), R (rechtshändig zirkular) and L (linkshändig zirkular) und mit Bildern der Polarisationsvektoren für jede davon. Zusätzlich befindet sich im Zentrum der Kugel das Koordinatensystem aus Stokesvektorkomponenten S₁, S₂ and S₃. |
| Date | |
| Source | Own work |
| Author | Geek3 |
| Other versions |
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| SVG development | Category:Valid SVG created with Python#Poincare-sphere%20arrows.svg  Category:Translation possible - SVGThis file uses embedded text that can be easily translated using a text editor. |
Source Code
The image is created by the following source-code. Requirements:
python source code:
try:
import svgwrite as svg
except ImportError:
print 'You need to install svgwrite: http://pypi.python.org/pypi/svgwrite/'
# documentation at http://pythonhosted.org/svgwrite/
exit(1)
from math import *
def to_xyz(theta, phi, r=1):
return r * sin(theta) * cos(phi), r * sin(theta) * sin(phi), r * cos(theta)
def to_theta_phi_r(x, y, z):
return atan2(z, sqrt(x**2 + y**2)), atan2(x, y), sqrt(x**2+y**2+z**2)
def rotx(x, y, z, a):
y, z = cos(a) * y + sin(a) * z, cos(a) * z - sin(a) * y
return x, y, z
def ellipse_path(theta, phi, tilt, flip=False):
t, p, r2 = to_theta_phi_r(*rotx(*(to_xyz(theta, phi, 1) + (tilt,))))
a = abs(r)
b = abs(r * sin(t))
return 'M %f,%f A %f,%f %f %i,%i %f,%f' % (-r*cos(p), -r*sin(p),
a, b, p*180/pi, 0, {True:1, False:0}[flip], r*cos(p), r*sin(p))
# document
size = 600, 600
doc = svg.Drawing('poincare-sphere_arrows.svg', profile='full', size=size)
doc.set_desc('poincare-sphere_arrows.svg', '''Drawing of a poincare-sphere with polarisations H, V, D, A, R and L, a coordinate system of Stokes-Vectors P1, P2 and P3 and six little images that illustrate the polarisations
rights: GNU Free Documentation license,
Creative Commons Attribution ShareAlike license''')
# settings
dash = '8,6'
col = 'black'
r = 240
tilt = radians(-70)
phi = radians(-25)
cp, sp = cos(phi), sin(phi)
# background
doc.add(doc.rect(id='background', profile='full', insert=(0, 0), size=size, fill='white', stroke='none'))
# arrow markers
arrow_d = 'M -4,0 L 2,-3 L 1,0 L 2,3 L -4,0 z'
arrow1 = doc.marker(id='arrow1', orient='auto', overflow='visible')
arrow1.add(doc.path(d=arrow_d, fill=col, stroke='none',
transform='rotate(180) scale(0.7)'))
doc.defs.add(arrow1)
arrow2 = doc.marker(id='arrow2', orient='auto', overflow='visible')
arrow2.add(doc.path(d=arrow_d, fill=col, stroke='none',
transform='scale(0.7)'))
doc.defs.add(arrow2)
arrow3 = doc.marker(id='arrow3', orient='auto', overflow='visible')
arrow3.add(doc.path(d='M 8.7185878,4.0337352 L -2.2072895,0.016013256 L 8.7185884,-4.0017078 C 6.9730900,-1.6296469 6.9831476,1.6157441 8.7185878,4.0337352 z', fill=col, stroke='none',
transform='scale(0.8) rotate(180)'))
doc.defs.add(arrow3)
# make a group for the sphere
sphere = doc.g(transform='translate(300, 300)', fill='none', stroke=col, stroke_width='2')
sphere['font-family'] = 'DejaVu Sans'
sphere['font-size'] = '42px'
doc.add(sphere)
# back ellipses
sphere.add(doc.path(d=ellipse_path(0, 0, tilt),
stroke_dasharray=dash, stroke=col))
sphere.add(doc.path(d=ellipse_path(pi/2, phi, tilt, True),
stroke_dasharray=dash, stroke=col))
sphere.add(doc.path(d=ellipse_path(pi/2, phi+pi/2, tilt),
stroke_dasharray=dash, stroke=col))
# draw coordinate axes
sphere.add(doc.circle(center=(0, 0), r=5, fill=col, stroke='none'))
for i in range(3):
xyz = [0, 0, 0]
xyz[i] = 0.3 * r
x, y, z = xyz
x, y, z = rotx(x*cp + y*sp, y*cp - x*sp, z, tilt)
line = doc.line(start=(0, 0), end=('%f' % x, '%f' % y), stroke=col)
line['marker-end'] = arrow3.get_funciri()
sphere.add(line)
# the six defined points
pts = []
for x,y,z in [[0,0,-1], [0,0,1], [0,-1,0], [0,1,0], [-1,0,0], [1,0,0]]:
x, y, z = rotx(r * (x*cp + y*sp), r * (y*cp - x*sp), r * z, tilt)
if z >= 0:
continue
pts.append((x, y))
sphere.add(doc.circle(center=('%f' % x, '%f' % y), r=6,
fill=col, stroke='none'))
# inset images
rect = doc.rect((-22, -22), (44, 44), fill='white', stroke=col, fill_opacity=0.88)
gV = doc.g(transform='translate(%f, %f)' % pts[1])
gV.add(rect)
gV.add(doc.line(start=(0,-11), end=(0,11), stroke_width=3,
marker_end=arrow1.get_funciri(), marker_start=arrow2.get_funciri()))
sphere.add(gV)
gA = doc.g(transform='translate(%f, %f)' % pts[2])
gA.add(rect)
gA.add(doc.line(start=(-7,-7), end=(7,7), stroke_width=3,
marker_end=arrow1.get_funciri(), marker_start=arrow2.get_funciri()))
sphere.add(gA)
gL = doc.g(transform='translate(%f, %f)' % pts[0])
gL.add(rect)
gL.add(doc.path(d='M -12,0 A 12,12 0 1,0 0,-12', stroke_width=3,
marker_end=arrow1.get_funciri()))
sphere.add(gL)
# V label
sphere.add(doc.text('V', text_anchor='middle',
transform='translate(144, -86)', stroke='none', fill=col))
# Stokes-Vector labels
sphere.add(doc.text('S₁', text_anchor='middle',
transform='translate(-56, 33)', stroke='none', fill=col))
sphere.add(doc.text('S₂', text_anchor='middle',
transform='translate(63, -2)', stroke='none', fill=col))
sphere.add(doc.text('S₃', text_anchor='middle',
transform='translate(-29, -59)', stroke='none', fill=col))
# sphere surface
grad1 = doc.defs.add(doc.radialGradient(id='grad1',
center=(0.375, 0.15), r=0.75, gradientUnits='objectBoundingBox'))
grad1.add_stop_color(offset=0, color='#FFF', opacity=0.3)
grad1.add_stop_color(offset=1, color='#DDD', opacity=0.3)
sphere.add(doc.circle(center=(0, 0), r=str(r),
fill='url(#grad1)', stroke='none'))
grad2 = doc.defs.add(doc.radialGradient(id='grad2',
center=(0.45, 0.45), r=0.575, gradientUnits='objectBoundingBox'))
grad2.add_stop_color(offset=0.6, color='#CCC', opacity=0)
grad2.add_stop_color(offset=0.8, color='#CCC', opacity=0.2)
grad2.add_stop_color(offset=1, color='#333', opacity=0.2)
sphere.add(doc.circle(center=(0, 0), r=str(r),
fill='url(#grad2)', stroke='none'))
# the six defined points
for x,y,z in [[0,0,-1], [0,0,1], [0,-1,0], [0,1,0], [-1,0,0], [1,0,0]]:
x, y, z = rotx(r * (x*cp + y*sp), r * (y*cp - x*sp), r * z, tilt)
if z < 0:
continue
pts.append((x, y))
sphere.add(doc.circle(center=('%f' % x, '%f' % y), r=6,
fill=col, stroke='none'))
# H, D, A, R, L labels
sphere.add(doc.text('H', text_anchor='middle',
transform='translate(-144, 115)', stroke='none', fill=col))
sphere.add(doc.text('D', text_anchor='middle',
transform='translate(272, 52)', stroke='none', fill=col))
sphere.add(doc.text('A', text_anchor='middle',
transform='translate(-272, -26)', stroke='none', fill=col))
sphere.add(doc.text('R', text_anchor='middle',
transform='translate(0, -261)', stroke='none', fill=col))
sphere.add(doc.text('L', text_anchor='middle',
transform='translate(0, 291)', stroke='none', fill=col))
# front ellipses
sphere.add(doc.path(d=ellipse_path(0, 0, tilt, True)))
sphere.add(doc.path(d=ellipse_path(pi/2, phi, tilt)))
sphere.add(doc.path(d=ellipse_path(pi/2, phi+pi/2, tilt, True)))
# circle edge
sphere.add(doc.circle(center=(0, 0), r=str(r)))
# inset images
gH = doc.g(transform='translate(%f, %f)' % pts[4])
gH.add(rect)
gH.add(doc.line(start=(-11,0), end=(11,0), stroke_width=3,
marker_end=arrow1.get_funciri(), marker_start=arrow2.get_funciri()))
sphere.add(gH)
gD = doc.g(transform='translate(%f, %f)' % pts[5])
gD.add(rect)
gD.add(doc.line(start=(-7,7), end=(7,-7), stroke_width=3,
marker_end=arrow1.get_funciri(), marker_start=arrow2.get_funciri()))
sphere.add(gD)
gR = doc.g(transform='translate(%f, %f)' % pts[3])
gR.add(rect)
gR.add(doc.path(d='M 12,0 A 12,12 0 1,1 0,-12', stroke_width=3,
marker_end=arrow1.get_funciri()))
sphere.add(gR)
doc.save()
Licensing
I, the copyright holder of this work, hereby publish it under the following licenses:
 |
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License. |
This file is licensed under the Creative Commons Attribution 3.0 Unported license.
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
You may select the license of your choice.
Category:Bloch spheres
Category:CC-BY-3.0
Category:GFDL
Category:Images with Python source code
Category:License migration redundant
Category:Octants of a sphere
Category:Photos by User:Geek3
Category:Polarization (waves)
Category:Self-published work
Category:Translation possible - SVG
Category:Valid SVG created with Python