Wednesday, October 31, 2012

Jesus, Google!

Apparently someone at Google has decided that composing an e-mail is too straightforward, and so they've decided to muck with Gmail yet again. Zoho, anyone?

Sunday, October 28, 2012


Some moron at TracFone put the following on their texting FAQ:

So is this 0.3 minutes? 0.3 cents? 0.3 dollars?

Friday, October 26, 2012

5 is Not Prime

Well, it is prime, but if we relax the requirement that it has no integer factors to allow complex numbers with integer components, i.e., a + bi where a and b are integers, then 5 is not prime.

(2 + i)(2 - i) = 4 -2i + 2i -i^2 = 4 - (-1) = 5

I love the BBC 4 program In Our Time. Listen to the discussion of the history of complex numbers at

Thursday, October 25, 2012

Screenshots in Gnome, Mate, etc.

[ Note added 2013-05-13: I now have a scrot-based shell script that does this better IMHO than does Imagemagick. See ]

The Gnome screenshot tool has always fallen a bit short in the usability department. How do I change the default directory for storing screen shots? How do I make it default to "select area to grab"? I've always just lived with it, but tonight decided to do a little legwork to learn how to make it default to what I wanted, and I found something better.

 I've long used ImageMagick for image editing. In some respects Mirage is easier to use, but Mirage doesn't handle as many image formats. I suppose the GIMP is more popular, but it's a usability nightmare. Google led me to a wonderful page at the Webmaster Tips Blog.

Assuming one has ImageMagick installed, taking a screenshot of a selected area on the screen is as simple as typing

    import filename.imagetype

and then selecting the area of the screen to copy.

As a concrete example, suppose I want to capture some text from above in file selectArea.png:

    import selectArea.png

The result is this, in a file called selectArea.png:

I like it.

Tuesday, October 23, 2012

Thumb Drive Undelete Files

A few weeks ago a student wanted to know how to undelete files on a FAT-formatted thumb drive. I knew I used to be able to do that with a Linux system--no guarantees of reliability of course--but a quick search turned nothing up. Actually, it's easy: just install testdisk, . To run, you may have to be superuser. It installs easily and works well (n of 1 study) on Mint 13, but any Debian-derived system is probably fine.

Monday, October 15, 2012

Sprint News: Too Little, Too Late

One week after I cancel my contract with Credo Wireless (and pay a $70 early termination fee--totally worth it) comes the news that Sprint may be expanding their cellular network if some other company kicks in some money. Credo is on the Sprint cellular network, and I can't say that anything like this is likely to entice me back. What Credo meant to me was a long-term commitment to a bad phone and poor signal strength. Sprint was the poor signal strength part of this. Credo/Sprint didn't provide a usable signal in my office, a good signal at my home, or any signal to speak of at my parents' house. Good riddance.