DescriptionExponentialchirp.png	English: A graph of a sinusoidal exponential chirp. It would be cool to show the f(t) function on the same graph. Any ideas?
Source	This file is licensed under the Creative Commons Attribution-Share Alike 2.0 Generic 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. https://creativecommons.org/licenses/by-sa/2.0CC BY-SA 2.0 Creative Commons Attribution-Share Alike 2.0 truetrue
Author	User:Omegatron

Instructions

See Wikipedia graph-making tips.

Newest version created in Maxima using the command:

x(t):=sin(2*%PI*(.1)*(3^t)*t);

So f₀ = 0.1 Hz, and k = 3, according to the equation given in the article:

${\displaystyle x(t)=\sin(2\pi f(t)t)=\sin(2\pi f_{0}k^{t}t)}$

It was then plotted using Maxima's gnuplot interface through the command:

 

This plot was created with Gnuplot.

To convert the PostScript file to PNG:

1. Open it in the GIMP (make sure you have ghostscript installed! - Windows instructions)
   • Enter 500 under Resolution (it doesn't say "DPI" but I think that's what it means)
   • Uncheck Try bounding box (since the bounding box cuts off the edge, unfortunately. You can try with the bounding box first.)
   • Enter large values for Width and Height
   • Check Color
   • Check Strong anti-aliasing for both graphics and text
2. Crop off extra whitespace (Shift+C if you can't find it in the toolbox)
3. Possibly need to rotate it: Click Image → Transform → Rotate 90 degrees clockwise
4. Filters → Blur → Gaussian blur at 2.0 px (No need to blur if you use strong anti-aliasing during conversion. I see no significant difference between end results.)
5. Image → Scale Image...
   • Width and Height at 25%
   • Cubic interpolation
6. You can view at normal size if you want by pressing 1, Ctrl+E
7. Save as Exponentialchirp.png

(There were some artifacts of the lines being "painted with a pointy brush" in the high frequency section, so I just clipped off the tops with the GIMP brush.)

Created by User:Omegatron using gnuplot, possibly with post-processing in the GIMP (PNG) or Inkscape (SVG)

I, the copyright holder of this work, hereby publish it under the following licenses:

This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported, 2.5 Generic, 2.0 Generic and 1.0 Generic 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.

https://creativecommons.org/licenses/by-sa/3.0CC BY-SA 3.0 Creative Commons Attribution-Share Alike 3.0 truetrue

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.http://www.gnu.org/copyleft/fdl.htmlGFDLGNU Free Documentation Licensetruetrue

You may select the license of your choice.

(In short, this means that you can copy and modify the image freely as long as you provide attribution; preferably in the form of a link back to this page.)