Regression with Gnumeric

A test regression (linear equation) using Gnumeric.

Finally, I’ve found a spreadsheet application (Gnumeric) with a reliable Solver for doing regressions. And it’s free. The only tricky part is that there’s no native port for Macs; you have to use a command line package manager to install it (I used Fink).

Gnumeric, however, seems to be an excellent tool for data analysis.

Mindmapping Online with Mind42

Excerpt from my pre-Algebra/Algebra mindmap created on Mind42.com

I was trying to figure out how I could create a graphic organizer/mindmap to outline my math class that my students could access online. Even better would be if they could also edit the map online. That way I could set up the outline of my lesson notes and they could fill in definitions for vocabulary words. Mind42 (pronounced mind for two) allows just that. It’s free to use and allows you to link to or embed your mindmaps (e.g. pre-Algebra/Algebra) into other websites:

It’s almost perfect, all it needs is for you to be able to save the state of the map, with certain branches collapsed for example, or with a set zoom level. Right now the best way to explore the above map is to collapse all the nodes (use the second button on the lower left) and gradually expand them out as you go through.

I do think the style of the nodes and lines on the maps are elegant and make it easy to read. It’s also really easy to create the maps.

Apart from putting your maps to other websites, you can also print them out as pdf’s or images (png), or you can save the map itself in a format that other mindmapping software, like Freemind, can use.

I really like this website, and as soon as they add the ability to save zoom levels and collapsed nodes I’m going to try using it for my classes.

Setting up a Computer with Free Software

[Updated: 7/22/17] The open-source and free-software movements have matured to the point where a teacher or student can reliably outfit a new computer with software that is free and compatible with their proprietary cousins.

The first place to look for free software for whatever purpose you need should probably be SourceForge. It feels odd having to say this, but it’s legal, free software. Mind you, it has a lot of programs that are still in development, many are not terribly polished, and not everything will be available for your operating system. Add in a few other pieces, like Firefox and OpenOffice, and you have all the basics you need for a basic loadout. I typically find these to be most useful.

  • LibreOffice or OpenOffice: Free, but not as powerful alternatives to MicroSoft Office. They can open and save MS Office files, but also has some of the irritating auto-formatting issues as Office. So for text editing I usually prefer Smultron (on Mac) or Atom (on Windows). Also, Gnumeric is an excellent alternative to Excel.
  • Atom (Windows and Linux): An extremely versatile text editor that a lot of my students like for coding.
  • Smultron (Mac): for writing text and only text, forget the formatting (and also useful for writing computer programs).
  • Firefox: For web browsing.
  • GIMP: instead of PhotoShop for editing images.
  • Inkscape: For drawing diagrams (like this one).
  • VUE: For mindmaps (like this) and flow charts.
  • Audacity: works well for sound editing (I’ve only used it a little for trimming sound files when I was trying to create sound effects). Unlike SOX (see below) Audacity has a user interface.
  • OpenSCAD: For creating 3d models using basic shapes (spheres, boxes etc.) for 3d printing.
  • VPython: I usually introduce my students to programming with VPython, which is a Pythno library for creating 3d visualizations. The VPython downloads pages include instructions for installing Python.

There are other odds and ends that you’ll find on my computer, like vlc for playing DVD’s, Combine PDF for rearranging pages in pdf documents, and TexShop for really nice typsetting, but there are a lot of good, free alternatives out there. Not a whole lot of games however.

Command Line Programs

If you’re comfortable using the Linux command line there are a number of programs, most of which have been ported to the major operating systems (and you can use the Cygwin program to use a lot of Linux commands if you’re on Windows), that can also be very useful:

  • SoX: For generating sound tones and notes (e.g.),
  • ImageMagick: the convert command is particularly useful for working with images (their example page is excellent). The GIMP is based on this program.
  • gifsicle: for help making animated gifs (particularly for optimizing them).

The Gimp: Photoshop’s Free Cousin

Observing moss.

For those of us too cheap to buy Photoshop, or who want to support the open-source movement, the Gimp is a great little image manipulation program. I use the “Oilify” option a lot to obscure students’ faces. Gimp’s not as sophisticated as Photoshop, but if you’re not heavily into graphic design, and are not too picky, it does a good job.

Jumping the creek. Be careful with the flaming sword; someone might get hurt. (Image created by Piper Ziebarth; photographer Lensyl Urbano).

As a Photoshop clone, Gimp shares many of its basic principles. It also comes from the ImageMagick command line tools, which I’ve used to automate image processing in the past.

Gimp itself is, however, pretty easy to learn. I’ve shown one student how to use it, and we’ll see if and how the knowledge propagates through the class.

Triplets? Clones? Or maybe robots?