Image:Nielsen's spiral.png

[edit] Summary

Plot of Nielsen's spiral, also known as the sici spiral.

This picture was created by Jitse Niesen using the following Matlab code:

ts = linspace(0.8, 30, 1000);
xs = 1/2i * (expint(ts*1i) - expint(-ts*1i)); % sine integral
ys = -1/2 * (expint(ts*1i) + expint(-ts*1i)); % cosine integral
plot(xs,ys, 'LineWidth', 2);
axis equal;
axis off;
print -dpng 'nielsen_tmp.png';
system('convert -trim -bordercolor white -border 10 +repage nielsen_tmp.png nielsen.png');

[edit] Licensing

I, the copyright holder of this work, hereby release it into the public domain. This applies worldwide. In case this is not legally possible: I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law. Afrikaans | Alemannisch | Aragonés | العربية | Asturianu | Български | Català | Česky | Cymraeg | Dansk | Deutsch | Eʋegbe | Ελληνικά | English | Español | Esperanto | Euskara | Estremeñu | فارسی | Français | Galego | 한국어 | हिन्दी | Hrvatski | Ido | Bahasa Indonesia | Íslenska | Italiano | עברית | Kurdî / كوردی | Latina | Lietuvių | Latviešu | Magyar | Македонски | Bahasa Melayu | Nederlands | ‪Norsk (bokmål)‬ | ‪Norsk (nynorsk)‬ | 日本語 | Polski | Português | Ripoarisch | Română | Русский | Shqip | Slovenčina | Slovenščina | Српски / Srpski | Svenska | ไทย | Tagalog | Türkçe | Українська | Tiếng Việt | Walon | ‪中文(简体)‬ | ‪中文(繁體)‬ | zh-yue-hant | +/-

• Trigonometric integral
• Nielsen's spiral