A square wave, showing discontinuities.

See Wikipedia graph-making tips.

Generated in gnuplot with the following script:

 

This plot was created with Gnuplot by n.

and data file:

square.dat

 # X	Y1
   -1	-1
   0	-1
   0	0
   0	1
   1	1
   1	0
   1	-1
   2	-1
   2	0
   2	1
   3	1

I tried to use set clip points to make the points not plot at the edges of the graph, but it wasn't working, so I just set the xrange and made the first and last points outside of the graph instead of right on the edges.

Then I converted the square.ps file to PDF, opened it in Adobe Illustrator, changed the fill style for the circles, changed the line style for the vertical lines, and saved.

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 Square wave closeup.png

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

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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

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