Sunday, January 27, 2013

Hands-free tablet holder, first prototype

One of my current projects is to build a hands-free tablet holder that so I can watch Netflix videos in bed on my Kindle Fire. My first attempt is here.

Using cardboard made it easy to quickly prototype this "head cave", and easy to recycle it (once it had served its purpose). I cut the square notches on the sides of the "Kindle hole" for the ear-bud cable.

This placed the Kindle close enough to my face that I could remove my glasses. I have bad eyesight. If I want to really look at something carefully, I always take off my glasses and hold the item within a few inches of my face. I don't know if there is something optically (as opposed to psychologically) different about looking at things this way. I do, however, feel like I really see what I'm looking at when I do this.

I watched a few hour and two-hour videos this way, but have consigned the box to the recycling bin. My eyes do not have the same prescription, so one eye has to dominate when focusing this closely. This leads to occasional strange effects when (I believe) the dominance switches from one eye to the other.

I'm now working on something using a Joby GorillaPod Focus that rests on my chest whilst in bed, so I can wear my glasses while watching.

Friday, January 11, 2013

Erratum (part 4) for D. S. Malik's "Data Structures Using C++"

Page 478 shows the "ADT" for a queue. I tend to read the code and skim the comments, given that I've been fooled more than once by out-of-date comments. I was therefore confused by the "addQueue" method. My first take was that it did what it said, e.g., added a queue to the existing queue. Going back through the comments, however, I found that it really was an "enQueue" operation.

When I looked up the STL syntax, I found that it uses push/pop (which I associate with stacks, not queues). In any case, it just seems confusing to use the name "addQueue" for this functionality.

See also other errata.


Are there any human proofreaders left?

"Watership Down" by Richard Adams, Scribner trade paperback edition 2005, page 14:

I daresay a good many rabbits would have kept quite and thought about keeping on the right side of the Chief...
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