User talk:Geek3/Archives/2018

Dispersion curve chart error

The following file is in question: https://commons.wikimedia.org/wiki/File:Mplwp_dispersion_curves.svg. Its axis label uses units of nanometers, yet the "visible region" is approximately between 0.4 and 0.8 (which would be valid if the units were microns). Zedtwitz (talk) 19:27, 20 January 2018 (UTC)

Yes, this obviously has error. I’d fix and upload over boldly unless this Python-based generating software. Incnis Mrsi (talk) 19:39, 20 January 2018 (UTC)

Thanks for noticing. I fixed it. --Geek3 (talk) 18:53, 21 January 2018 (UTC)

Notation in physics and math

Hello.
You make a fairly good job with physics images, but one critical remark. Please, do not copy various mediocre students or crook-handed poor designers who use ASCII rubbish (like “+-m”), Roman variables, etc. Speak proper notation, please. Incnis Mrsi (talk) 13:10, 3 February 2018 (UTC)
By the way, Moisés André Nisenbaum (or some of his students who drew this rubbish for grades) are even less than ignorant in typography. They denoted the azimuthal quantum number (ℓ) with Roman sans-serif “l”, whereas made spectroscopic letters (s, p, d, etc.) italic. They deserve a negative grade for such a product. Incnis Mrsi (talk) 13:48, 3 February 2018 (UTC)

Thanks for the remark! You are right, “+-” is just a bad approximation for “±” and the Wikimedia projects have very good support for the correct unicode characters. To go one step further, I even think Minus should be “−” and not “-”. In actual articles I would never use such approximations. I think it only happened in cleanup templates or filenames. In the latter, having pure ASCII characters may be a significant advantage, as these files may be copied to various operating systems etc.. --Geek3 (talk) 15:09, 3 February 2018 (UTC)

I do not object against ASCII filenames (when possible), but {{Factual accuracy}} is not about filenames in any way. BTW, support of Unicode depends not as much on MediaWiki as on desktop environment. Moreover, a Unicode wiki text can be encoded even in pure 7 bit, using character references. Incnis Mrsi (talk) 15:27, 3 February 2018 (UTC)

D4M2.png > D4xy.png (?)

Check the filename you suggested in D4M2.png; it's basically the same one that you used in D4M1.png (now D4xy.png), and it is not possible that these have the same new filename. Regards, Jarould [talk] 20:49, 3 February 2018 (UTC)

Thanks for letting me know! I was being sloppy, and swapped some of the indices. The correct renaming is D4M1.png -> D4xz.png and D4M2.png -> D4xy.png. I will trigger new renaming accordingly. --Geek3 (talk) 20:57, 3 February 2018 (UTC)

@Jarould: I effected two moves in a chain. Please, check that description pages are up-to-date and no damage to wikipedias are inflicted – I resorted to Special:MovePage for what is now File:D4xz.png. I hope you will do the job. Incnis Mrsi (talk) 17:35, 4 February 2018 (UTC)

Thanks for the moving! The names seem to be fine now. One of the links was thereafter pointing to the wrong file (Former D4M1.png points to D4xy.png instead of D4xz.png). I fixed it in the English Wikipedia. --Geek3 (talk) 00:17, 5 February 2018 (UTC)

D4M1:, D4M2: – not good. Incnis Mrsi (talk) 06:48, 5 February 2018 (UTC)

Yes, you edited File:D4M1.png (hist • logs • abuse log) on Commons, but it matters little now. Search for “D4M1” in https://tools.wmflabs.org/guc/?src=rc&by=date&user=Jarould , please. Some of these erroneous changes are probably not fixed yet (note I didn’t replace “xy” with “xz” because hurried to reoccupy “D4xy.png” which was made red by Special:MovePage, in turn necessary to give me an ability to move “D4M2.png” to the desired name). Incnis Mrsi (talk) 13:56, 5 February 2018 (UTC)

I understand that the correction in the redirection page came too late, as the automatic renaming of all links to D4M1.png was already performed. So there are a couple of falsely linked images D4M1.png floating around on Wikipedia projects, but they are easy to spot. I will fix these remaining ones as well. --Geek3 (talk) 15:52, 5 February 2018 (UTC)

I fixed all false ocurences of D4xy.png, so the problem should be solved. --Geek3 (talk) 22:02, 5 February 2018 (UTC)

Quality Image Promotion

Your image has been reviewed and promoted Congratulations! Helmholtz coils.png, which was produced by you, was reviewed and has now been promoted to Quality Image status. If you would like to nominate another image, please do so at Quality images candidates. We also invite you to take part in the categorization of recently promoted quality images. Comments Good quality. --Basotxerri 16:15, 14 March 2018 (UTC)

--QICbot (talk) 05:15, 17 March 2018 (UTC)

Azimuthal quantum number

Hello.
Let you learn that the standard notation for it is «ℓ» (TeX: \ell), not «$l$» or some sans-serif rubbish like «l». By the way, using sans-serif for scientific notation is a sign of ignorance unless in few special cases (such as «A^T») where sans-serif is intentionally used to distinguish an operation sign from a variable. Incnis Mrsi (talk) 19:07, 18 March 2018 (UTC)

No. There is definitively no consent in the scientific community to use «ℓ» for the total angular momentum quantum number. In fact most textbooks use «$l$». Here are three examples: Feynman's lectures on physics, Griffiths and Landau-Lifschitz. When it comes to serif or sans-serif it really depends on what font the author or web designer has settled for. --Geek3 (talk) 19:28, 18 March 2018 (UTC)

In fact, I'm curious where this ℓ-notation originates from. --Geek3 (talk) 18:40, 19 March 2018 (UTC)

Quality Image Promotion

Your image has been reviewed and promoted Congratulations! Atomic orbitals spdf m-eigenstates.png, which was produced by you, was reviewed and has now been promoted to Quality Image status. If you would like to nominate another image, please do so at Quality images candidates. We also invite you to take part in the categorization of recently promoted quality images. Comments Good quality. --Basotxerri 06:59, 25 March 2018 (UTC)

--QICbot (talk) 05:23, 28 March 2018 (UTC)

gamma

I can't understand how you created that gamma function of x and y. — Preceding unsigned comment was added by 203.223.189.214 (talk) 10:24, 17 May 2018 (UTC)

Which file exactly do you mean? The gamma function of complex argument x+iy? Ideally the source code should be given with the exact applied function. Standard functions of imaginary arguments are well defined by mathematicians in complex analysis. Specifically all important expressions for the gamma function are given in the article “gamma function”. --Geek3 (talk) 13:54, 17 May 2018 (UTC)

mplwp on Github

Hello

I am new to all things wiki but want to contribute. I like the work you have done with mplwp and was wondering if you had plans to host the code on github or another code hosting platform? I think developing a python package that could be distributed on https://pypi.org/ would be really great. — Preceding unsigned comment added by Eitanlees (talk • contribs) 19:14, 11 June 2018 (UTC)

Hi, and thanks for your interest. So far I put the code directly on Commons, so it is ensured that it can always be accessed with the graphics. Also to fulfill some of the open source licenses it is good to have the code directly available. It could make sense to put it on a source code hosting platform as well. After the recent acquisition I would strongly oppose Github, but Bitbucket, GitLab or other platforms could be a good choice. Mplwp in particular I think is not worth packaging. There is Matplotlib, a wonderful plotting library, but mplwp just adds a little customization to it. Some of my other scripts would probably need a higher level of completeness in order to turn them into a python package, and right now I don't have the time to do that. If you are interested in developing packages I can of course help. --Geek3 (talk) 20:11, 11 June 2018 (UTC)

Round 2 of Picture of the Year 2017 is open!

You are receiving this message because you voted in R1 of the 2017 Picture of the Year contest, but not yet in R2.

Dear Geek3/Archives,

Wikimedia Commons is happy to announce that the second round of the 2017 Picture of the Year competition is now open. This year will be the twelfth edition of the annual Wikimedia Commons photo competition, which recognizes exceptional contributions by users on Wikimedia Commons. Wikimedia users are invited to vote for their favorite images featured on Commons during the last year (2017) to produce a single Picture of the Year.

Hundreds of images that have been rated Featured Pictures by the international Wikimedia Commons community in the past year were entered in this competition. These images include professional animal and plant shots, breathtaking panoramas and skylines, restorations of historical images, photographs portraying the world's best architecture, impressive human portraits, and so much more.

There are two total rounds of voting. In the first round, you voted for as many images as you liked. In Round 1, there were 1475 candidate images. There are 58 finalists in Round 2, comprised of the top 30 overall as well as the top 2 from each sub-category.

In the final round, you may vote for a maximum of three images. The image with the most votes will become the Picture of the Year 2017.

Round 2 will end on 22 July 2018, 23:59 UTC.

Click here to vote now!

Thanks,
the Wikimedia Commons Picture of the Year committee 11:32, 17 July 2018 (UTC)

Questions?

Hi Geek3,

I saw your sphere image. I'd like to get in touch with you, as I have a slight interest in possibly creating some similar graphics. Could you leave your e-mail somewhere or provide a link to one of your social media profiles where I could get in touch?

Thanks! — Preceding unsigned comment was added by 172.58.59.39 (talk) 22:08, 7 August 2018 (UTC)

Hello 172.58.59.39,

it's probably easiest if you ask me right here on the talk page, it won't bother anyone. The sphere image you're probably refering to, was created with a 1200-line python script, which produces the svg text file. From today's perspective, the script is overly complicated, which is why I never published it. I was working on a more elegant generalized version, but that's on hold due to time constraints.

I'm happy to help you creating similar graphics. What aspect are you interested in?

• The creation of the svg-file was achieved using xml.dom, but today I would rather recommend svgwrite, if not more high-level.
• The geometric aspects of drawing the sphere was achieved with standard geometry. You walk along a circle, rotate it in 3D and then do the perspective projection into the image plane.
• The conversion to smooth Bezier curves was done with numerical optimisation. This could be done way simpler just using fixed intervals and heuristic control-point distances.

--Geek3 (talk) 22:32, 7 August 2018 (UTC)

density of ice plot

Hey Greek3, i like to ask which exact function did you used for plotting the density of ice in one of your selfmade graphs? I like to use the value for T = -196°C for my bachelor thesis. I don't find any other sources which plot the density this low.

Greetings, Thorben — Preceding unsigned comment was added by 134.169.216.79 (talk) 17:42, 12 August 2018 (UTC)

Hi, as stated on the source page Density_of_ice_and_water_(en).svg, the values are from a book: Chapter 3.22d of http://www.ptb.de/cms/fileadmin/internet/publikationen/buecher/Kohlrausch/Tabellen/Kohlrausch_3_Tabellen_und_Diagramme_Waerme.pdf . The curve is interpolated from these. Using the quadratic fit and extrapolation, one obtains: density(T=−196°C) = 0.9346±0.0003 g/cm³. The uncertainty tells you how accurate the estimated value is. There could be better values in the literature. --Geek3 (talk) 18:43, 12 August 2018 (UTC)

ow! how impressive!

Estimado Geek3. Your images are so impressive & beautiful. Tank you! As a little present, a poet said: Tollimus ingentes animos, at maxima parvo tempore molimur. gracias.Vaconius (talk) 19:17, 29 October 2018 (UTC)

Thank you Vaconius, I appreciate it :). --Geek3 (talk) 10:35, 5 November 2018 (UTC)

poincare sphere

Dear Geek3, i´d like to use the image ( https://commons.wikimedia.org/wiki/File:Poincar%C3%A9_sphere.svg) and want to adapt it a little bit. Can you give me the python-code? logruen

Here's the code. However some elements are not created by the code but were added manually. But the script will do the spherical geometry for you and create a correct orthographic projection, while you can change the angles. You could make certain adaptions also manually in the svg- (Text) file or with Inkscape.

#!/usr/bin/env python3
# -*- coding: utf8 -*-

try:
    import svgwrite as svg
except ImportError:
    print('requires svgwrite library: https://pypi.org/project/svgwrite/')
    # documentation at https://svgwrite.readthedocs.io/
    exit(1)

from math import *

# geometry
r = 140.
rA = 176.
phi0 = radians(-25)
phi = radians(55)
theta0 = radians(28)
theta = radians(30)
dash = '6,6'

# document
size = 360, 360
name = 'Poincare_sphere'
doc = svg.Drawing(name + '.svg', profile='full', size=size)
img = doc.add(doc.g(id='image', fill='none', stroke='#000000', stroke_width='1',
    transform='translate({0},{1}) scale({2},-{2})'.format(
                size[0]/2., size[1]/2., 1.)))

w = atan2(cos(phi0+phi), sin(theta0) * sin(phi0+phi))
img.add(doc.path(d='M {0},{1} A {2},{3} {4} 0 0 {5},{6}'.format(r*cos(w),
    -r*sin(w), r, r*cos(theta0)*sin(phi0+phi), degrees(-w), -r*cos(w), r*sin(w)),
    stroke_dasharray=dash, stroke='#808080'))

# axes
img.add(doc.line(start=(-rA*sin(phi0), rA*cos(phi0)*sin(theta0)),
    end=(rA*sin(phi0), -rA*cos(phi0)*sin(theta0))))
img.add(doc.line(start=(-rA*cos(phi0), -rA*sin(phi0)*sin(theta0)),
    end=(rA*cos(phi0), rA*sin(phi0)*sin(theta0))))
img.add(doc.line(start=(0, -rA*cos(theta0)),
    end=(0, rA*cos(theta0))))

img.add(doc.path(d=
	'M {0},{1} A {2},{3} 0 1 1 -{0},{1}'.format(r, 0, r, r*sin(theta0)),
	stroke_dasharray=dash, stroke='#808080'))
img.add(doc.path(d=
	'M -{0},{1} A {2},{3} 0 1 1 {0},{1}'.format(r, 0, r, r*sin(theta0))))

# phi bow
img.add(doc.path(d=
	'M 0,0 L {0},{1} A {2},{3} 0 0 1 {4},{5} Z'.format(r*sin(phi0), -r*cos(phi0)*sin(theta0), r, r*sin(theta0), r*sin(phi0+phi), -r*cos(phi0+phi)*sin(theta0)),
	fill='#204a87', stroke='none', opacity=0.2))
img.add(doc.path(d=
	'M {0},{1} A {2},{3} 0 0 1 {4},{5}'.format(r*sin(phi0), -r*cos(phi0)*sin(theta0), r, r*sin(theta0), r*sin(phi0+phi), -r*cos(phi0+phi)*sin(theta0)), stroke_width=2, stroke='#204a87'))

# theta bow
img.add(doc.path(d=
	'M 0,0 L {0},{1} A {2},{3} {4} 0 1 {5},{6} Z'.format(r*sin(phi0+phi), -r*sin(theta0)*cos(phi0+phi), r, r*cos(theta0)*sin(phi0+phi), degrees(-w), r*sin(theta)*sin(phi0+phi), r*(cos(theta0)*cos(theta)-sin(theta0)*sin(theta)*cos(phi0+phi))),
	fill='#f57900', stroke='none', opacity=0.3))
img.add(doc.path(d=
	'M {0},{1} A {2},{3} {4} 0 1 {5},{6}'.format(r*cos(w), -r*sin(w),
	r, r*cos(theta0)*sin(phi0+phi), degrees(-w), -r*cos(w), r*sin(w))))
img.add(doc.path(d=
	'M {0},{1} A {2},{3} {4} 0 1 {5},{6}'.format(r*sin(phi0+phi), -r*sin(theta0)*cos(phi0+phi), r, r*cos(theta0)*sin(phi0+phi), degrees(-w), r*sin(theta)*sin(phi0+phi), r*(cos(theta0)*cos(theta)-sin(theta0)*sin(theta)*cos(phi0+phi))),
	stroke_width=2, stroke='#f57900'))

# radial vector
img.add(doc.path(d=
	'M {0},{1} L {2},{3}'.format(0, 0, r*sin(theta)*sin(phi0+phi), r*(cos(theta0)*cos(theta)-sin(theta0)*sin(theta)*cos(phi0+phi))),
	stroke_width=2, stroke='#4e9a06'))

img.add(doc.circle(cx=0, cy=0, r=r, stroke_width=2))
doc.save(pretty=True)

--Geek3 (talk) 22:39, 5 November 2018 (UTC)

Some bubble tea for you!

Thank you for your works. IceTiki (talk) 15:18, 5 November 2018 (UTC)

Graph of resistivity

The graph of metal resistivity is excellent, but unfortunately you've labelled silver as Ar, whereas its symbol is Ag. If you could create an updated version, that would be good.--Phil Holmes (talk) 15:34, 1 December 2018 (UTC)

Thanks!! Good point...--Geek3 (talk) 15:35, 1 December 2018 (UTC)

I look forward to receiving your help

Hello, I am a student. I'm doing a project on ballistic trajectory with air resistance.I found a few ideas from your code but currently I'm programming with matlab so I do not understand the commands in your code. I'm trying to draw such a chart with matlab. I hope that you can help me convert your code compatible with matlab's programming language. I am really grateful to you for this!

https://upload.wikimedia.org/wikipedia/commons/b/bd/Mplwp_ballistic_trajectories_angles.svg The plot was generated with mplwp 1.6.3

#!/usr/bin/python
# -*- coding: utf8 -*-

import matplotlib.pyplot as plt
import matplotlib as mpl
import numpy as np
from math import *

code_website = 'http://commons.wikimedia.org/wiki/User:Geek3/mplwp'
try:
    import mplwp
except ImportError, er:
    print 'ImportError:', er
    print 'You need to download mplwp.py from', code_website
    exit(1)

name = 'mplwp_ballistic_trajectories_angles.svg'
fig = mplwp.fig_standard(mpl)

xlim = 0,515/355.; fig.gca().set_xlim(xlim)
ylim = 0,1; fig.gca().set_ylim(ylim)
fig.gca().yaxis.set_major_locator(mpl.ticker.MultipleLocator(0.2))

from scipy.integrate import odeint
from scipy.optimize import brentq
def ballistic(g, k, xy0, v0, alpha0, tt):
    # use a four-dimensional vector function vec = [x, y, vx, vy]
    def dif(vec, t):
        v = sqrt(vec[2]**2 + vec[3]**2)
        return [vec[2], vec[3], -k*v*vec[2], -g -k*v*vec[3]]
    
    # solve the differenctial equation numerically
    vec = odeint(dif, [xy0[0], xy0[1], v0*cos(alpha0), v0*sin(alpha0)], tt)
    return vec[:,0], vec[:,1] # return x(tt) and y(tt)

g = 1.0
k = 2.0
v0 = 5.0
for i, alpha0 in enumerate(np.linspace(0, pi/2, 7)[1:-1]):
    t1 = brentq(lambda t: ballistic(g,k,[0,0],v0,alpha0,[0,t])[1][1],0.1,5)
    t = np.linspace(0, t1, 5001)
    x, y = ballistic(g, k, [0, 0], v0, alpha0, t)
    while len(y) > 1 and y[-2] <= 0.0: x = x[:-1]; y = y[:-1]
    plt.plot(x, y, zorder=-i,
        label=ur'$\alpha_0=\,{:.0f}$°'.format(degrees(alpha0)))

mpl.rc('legend', borderaxespad=0.8)
plt.legend(loc='upper right')
plt.savefig(name)
mplwp.postprocess(name)

— Preceding unsigned comment added by Crystal Huynh (talk • contribs) 05:03, 7 December 2018 (UTC)

Hi, most of it should be self explanatory. All the physics happens in the function ballistic(). The function creates two output vectors of x and y values. The trick is to define the derivative function dif(), which returns four derivatives, of x, y, dx/dt and dy/dt. See Ordinary_differential_equation#Reduction_to_a_first-order_system. The derivatives are given by the physical laws that ${\vec {a}}(t)=-k\cdot v(t)\cdot {\vec {v}}(t)+{\vec {g}}$. Once the derivative is defined, I can use scipy.integrate.odeint(). Matlab has similar functions, like ode45, so the translation is straightforward. In fact, it's also explained on the image page File:Mplwp_ballistic_trajectories_angles.svg. --Geek3 (talk) 19:34, 7 December 2018 (UTC)