That free U2 album

There were two different ways that "Songs of Innocence" could have been made available for free on iTunes --- "push" vs. "pull".

Apple and U2 are probably wishing by now that they had chosen the "pull" option, where the price on the iTunes store shows up as "free" and customers can then decide to "purchase it". (Weekly free songs are offered this way up on the store.)

Instead, a more novel "push" approach was used, where, if you had the right settings, the album would show up on your "purchased" list. (This, theoretically, could cost someone large bandwith fees if, say, the album got downloaded when they were roaming internationally.) Clearly a conscious decision,.

Here's the irony: I am a music hound. And I like U2. (The recent stuff not as much as the early stuff, but anywhoo.) I wanted to get the album. However, my iTunes settings have the "download purchased music automatically" turned *off*. So I actually had to spend some time, and look around for a few instructions, before I could get the actual songs into my playlist.

D3 color consistency

If you want to get consistent colors across D3 charts, say, when using the estimable dc.js, you will need to share the color category object across the two charts. In particular, this will not work:

chart1.colors(d3.scale.category10())

...


chart2.colors(d3.scale.category10())

Instead, you want:

var mycategory = d3.scale.category10()
chart1.colors(mycategory)
chart2.colors(mycategory)

(Assuming also, of course, that the colors on each chart are based on corresponding data fields.)