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When should you make the effort to learn something? It’s a question of investment strategy regarding time, energy and, not infrequently, money. One approach is to assess if the learning can be put off until just prior to its anticipated time of need, and if so, do that. This follows the wisdom that you should wait to invest until waiting any longer will reduce your anticipated return on all investments or lose you the opportunity to invest. An application of this parsimonious principle seen in business as well as software design is an approach called “just in time.” The author of this post asks, how do we apply this principle to learning, and when is it appropriate?

What do you learn just in case you’ll need it in the future, and what do you learn just in time when you do need it?

In general, you learn things in school just in case you’ll need them later. Then once you get a job, you learn more things just in time when you need them.

When you learn just in time, you’re highly motivated. There’s no need to imagine whether you might apply what you’re learning since the application came first. But you can’t learn everything just in time. You have to learn some things before you can imagine using them. You need to have certain patterns in your head before you can recognize them in the wild.

Originally published at BeyondLogical.net/blog. Please leave any comments there.

Virtualbox upgrade hanging on Dropbox

Eye

I was upgrading Virtualbox on an XP host the other day and it seemed to stall toward the end. I hit “Cancel” and nothing happened, but when I logged off it politely rolled back its changes and quit. I tried it again, same thing. Then I realized I had dropbox running, closed it, and the upgrade carried on to completion. I’m guessing this is because virtualbox needs to restart the network interfaces and can’t do so while dropbox has a connection open. Why dropbox would hold a connection open instead of polling periodically is beyond me. I can confirm I wasn’t syncing at the time, so this is the normal state while the dropbox client is running.

Originally published at BeyondLogical.net/blog. Please leave any comments there.

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Eye

echo “This goes to the clipboard” > /dev/clipboard

It’s that simple… usually. For some reason some program output going to STDOUT doesn’t end up there. There is a simple fix, that being to pipe it through cat first:

echo “This goes to the clipboard” | cat > /dev/clipboard

Originally published at BeyondLogical.net/blog. Please leave any comments there.

Eye

Upon upgrading to 3.2.8 and re-starting a client you might get an error message such as:
“differencing image not associated with parent”
“differencing but not associated with any parent in media registry”
“Parent medium with UUID x not found in media registry”

For some reason, inaccurate info ended up in your vdi file. VB is now more strict, and this inaccurate information just needs to be expunged to prevent VB from panicing. See this ticket for details:

http://www.virtualbox.org/ticket/7289

The short of it is: You download the tool for your host platform:

http://www.virtualbox.org/download/VBoxFixHdd/

“Identify the affected images. You can either use the VirtualBox GUI and check which base images are inaccessible, but shouldn’t be. The same can be done with “VBoxManage list hdds”, in this case make sure you only look at images which say “Parent UUID: base”.
Run the repair tool:
VBoxFixHdd –filename /path/to/image.vdi –zeroparentuuid
Repeat for all affected images.”

Worked like a charm.

Originally published at BeyondLogical.net/blog. Please leave any comments there.

Eye

The Soladey-J3X [toothbrush] has a solar panel at its base that transmits electrons to the top of the toothbrush through a lead wire. The electrons react with acid in the mouth, creating a chemical reaction that breaks down plaque and kills bacteria. The toothbrush requires no toothpaste, and can operate with about the same amount of light as needed by a solar-powered calculator.
(PhysOrg.com)

Originally published at BeyondLogical.net/blog. Please leave any comments there.

Bulldozers and Spatial Cognition

Eye

Suppose you want to take a picture of yourself laying down in the mud in front of a bulldozer. What side should the bulldozer be on when you take the picture?

Does the directionality of a person’s primary writing system (left-to-right, top-to-bottom for English) affect the way in which they take in other compositions, such as a photo or painting, creating a “perceptual directionality”? If so, should visual composition be informed by knowledge of the target audience’s perception directionality? After a brief search I came up with this paper, which seems to indicate that I’m not too far off the mark.

Writing Direction Influences Spatial Cognition


Now that doesn’t exactly answer the original question, although it does inform the decision of how to compose the shot.

Originally published at BeyondLogical.net/blog. Please leave any comments there.

Eye

Due to (a bug in) the way fonts are rendered in the “SQL Query Area” of the MySQL Query Browser[1], most of the fonts available end up looking clipped. Beyond aesthetics, you might want to change the default font due to its lack of support for UTF-8 characters. You can change the “Code Font” choice under Tools > Options > General Options.
I prefer Arial Unicode MS 8.3pt for default & data, but due to it rendering poorly in the code area I’m using Bitstream Vera Sans Mono 8pt as a tolerable alternative. Both support UTF-8.
[1] MySQL Query Browser 1.2.17 on Windows XP.

Originally published at BeyondLogical.net/blog. Please leave any comments there.

Test more PHP!

Eye

It’s not just an admonishment, it’s the name of a project I maintain at code.google.com.

test-more-php version 0.1 is out now and ready to help prevent hours of debugging with so little effort it’s ridiculous not to use it. The API is a direct port of the popular Perl Test-More library with some minor PHP adaptations. Both object and procedural interfaces are available, so pick your flavor and get coding!

I started test-more-php after getting sucked into writing PHP full-time and casting about for a testing library with the elegance I knew from Test-More. Eventually I discovered a few, but each was incomplete or failed me by silently bailing on an error that could have been reported appropriately. Test-More.php is a drop-in replacement for those other libraries and provides me with the confidence that, if something goes wrong, I will know about it.

I’ve tested it under Windows XP, Ubuntu Linux, FreeBSD and Cygwin but not OS X, so if anyone with a Mac wants to take it for a spin please let me know how if it passes all it’s tests. (Of course it comes with its own test suite!)

Originally published at BeyondLogical.net/blog. Please leave any comments there.

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Eye

The title of this post at dagolden.com really struck me. The post, about a new CPAN client that doesn’t mimic the “swiss army chainsaw” mentality of the Perl community’s approach to software design, is apt in its critique not only of the project itself, but of its reception by the community. There is a religious type zeal some people express when shifting their allegiance from one idea to another that seems to compel them to attack the subject of their former allegiance.

Originally published at BeyondLogical.net/blog. Please leave any comments there.

Douglas Crockford — The JSON Saga

Eye

This talk by Douglas Crockford, standard bearer of JSON, is an interesting history lesson on JSON’s origins. Douglas provides plenty of amusing perspective on JSON’s position as the popular data interchange format it has become and the landscape it evolved in. He seems to enjoy taking a “heretical” perspective, which is usually more fun to listen to in a tech talk, and this is no exception.One recurring theme that caught my attention was the aspiration to simplicity in the format, especially in comparison to xml. It’s a lesson worth revisiting.

Originally published at BeyondLogical.net/blog. Please leave any comments there.

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