File:QuadrupoleContour.svg

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Original file ‎(SVG file, nominally 540 × 540 pixels, file size: 158 KB)

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Summary[edit]

Description
English: Contour plot of the equipotential surfaces of an electric quadrupole field. The field is accurately computed from a physical model.
Date
Source Own work
Author Geek3
SVG development
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The SVG code is valid.
 
This plot was created with Matplotlib.
Source code
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Python code

import numpy as np
from matplotlib import pyplot as plt
from matplotlib import colors

def simplify_contours(qcset, thresh=plt.rcParams['path.simplify_threshold']):
    for c in qcset.collections:
        paths = c.get_paths()
        for i, p in enumerate(paths):
            p.simplify_threshold = thresh / plt.gcf().dpi
            paths[i] = p.cleaned(simplify=True)

xmax = 3.2
vmax = 4
levels = np.linspace(-vmax, vmax, 22)
X, Y = np.mgrid[-xmax:xmax:400j, -xmax:xmax:400j]
V  = 1.0 / np.maximum(np.sqrt((X + 1)**2 + (Y + 1)**2), 1e-5)
V += 1.0 / np.maximum(np.sqrt((X - 1)**2 + (Y - 1)**2), 1e-5)
V -= 1.0 / np.maximum(np.sqrt((X + 1)**2 + (Y - 1)**2), 1e-5)
V -= 1.0 / np.maximum(np.sqrt((X - 1)**2 + (Y + 1)**2), 1e-5)
plt.figure(figsize=(6, 6)).add_axes([0, 0, 1, 1])
contf = plt.contourf(X, Y, V, levels=levels, cmap='RdBu_r', extend='both',
       norm=colors.SymLogNorm(linthresh=1.5, vmin=-vmax, vmax=vmax))
simplify_contours(contf, plt.rcParams['lines.linewidth'])
cont = plt.contour(X, Y, V, levels=contf.levels, colors='k', linestyles='solid')
plt.xticks([]), plt.yticks([])
plt.gca().set_aspect(aspect='equal')
plt.gca().axis('off')
for i in -1,1:
    for j in -1,1:
        plt.text(i, j, {-1:u'\u2212', 1:'+'}[i*j],
                 size=18, ha='center', va='center')
plt.savefig('QuadrupoleContour.svg')

Licensing[edit]

I, the copyright holder of this work, hereby publish it under the following license:
w:en:Creative Commons
attribution share alike
This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International 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.
  • share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.

File history

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Date/TimeThumbnailDimensionsUserComment
current22:52, 14 May 2018Thumbnail for version as of 22:52, 14 May 2018540 × 540 (158 KB)Geek3 (talk | contribs)Potential must be 1/r, not 1/r².
14:40, 22 October 2017Thumbnail for version as of 14:40, 22 October 2017540 × 540 (195 KB)Geek3 (talk | contribs)User created page with UploadWizard

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