Wednesday

May. 9th, 2007 10:47 pm
bjarvis: (not poison)
[personal profile] bjarvis
Today's Linux class was no more exciting than Monday or Tuesday. Largely, we wrote little shell scripts so the Linux newbies can claim they've done scripting. For the hell of it, I wrote a quick bash shell implementation of Zeller's Congruence.

And then the class got really boring. :-(

I slipped around 2 PM or so when they started discussing file ownerships & permissions and some standard configuration files (/etc/passwd, /etc/shadow, etc.).

Up to that point, I was largely amusing myself with creating file systems on four new servers, running backups on a few others, reviewing UNIX work tickets and preparing to move another server into a new cabinet.

Traffic homeward was pure hell but I managed to save a little time with a judicious selection of back roads and side streets. I even managed to get an hour's nap before heading to C1 dancing in Arlington this evening.

Dancing was lots of fun as usual. I called a C1 tip which was largely well received. One figure was a little ambiguous in its closing formation: I could see arguments why the final arrangement could be a butterfly or lines facing out. While I had planned on lines --and the dancers kindly obliged me-- I'll rewrite that sequence to assume butterflies and take appropriate advantage as I don't have many butterfly sequences in my limited collection thus far.

Time for bed now...

Date: 2007-05-11 02:43 pm (UTC)
From: [identity profile] stormecho.livejournal.com
As I expected - you are correct. Stand firm and let the dancers know. The ends of cast a shadow must always end as ends of lines, regardless of the shape of the centers. They must spread and breathe to be in tandem. You don't create space just because they don't breathe properly.

Date: 2007-05-11 04:50 pm (UTC)
zipperbear: (Default)
From: [personal profile] zipperbear
In this case (Ends Cast a Shadow while the Centers Counter-Rotate 1/4), I agree that Lines is the only reasonable interpretation.

But consider what happens if you start in Diamonds, and the Points do their part of Cast a Shadow. They can either go to End-of-Lines spots (opt for an H), or they can become Tandems on the outside (opt for an I, a.k.a. a Bone). The same ambiguity happens in an H when the Center Wave does a Lock It (either working Matrix, to make Diamonds, or working Triple Waves, to make perpendicular Triple Waves by having the outsides breathe outward). A similar issue arises with the Box of an Hourglass doing a Counter-Rotate, with the assumption that the Box is isomorphic to itself (creating a t-boned or "Dunlap" Hourglass -- if'n one Phantom Hourglass done lap over t'other), as opposed to having the Hourglass Points working as a Tandem and doing a Counter-Rotate around the outside (creating a Lantern or Tie-Fighter formation). If you have a choice of isomorphisms (Hourglass Points can be Ends of Lines, or Ends of Triple Lines, or Butterfly Ends), then disagreements can arise if you're not explicit about which one you want.

The modern preference for treating the Ends part of Cast a Shadow as being just an equivalent for Concentric Zig-Zag or Zag-Zig (i.e. Reverse Trixie) is somewhat distasteful to me, because it ignores the subtle nature of the definition, and the actual dance motions of the dancers.

Cast a Shadow has the Centers doing a Clover and Extend-Hinge-Extend. The Clover takes dancers to the outside in a very flexible way. The Extend takes dancers out of the middle in a way that vacates the center spots, and allows the Ends to breathe into the vacuum. The Ends are doing a Spread, which implicitly pulls in the Clovering dancers.

I recommend that you say what you want: "Ends Cast a Shadow, spreading all the way to become Ends of Lines, while the Centers Counter-Rotate 1/4" or "Ends Only, Cast a Shadow, Opt for Butterfly spots."

Date: 2007-05-11 07:28 pm (UTC)
From: [identity profile] stormecho.livejournal.com
What Stewart said.

January 2021

S M T W T F S
     1 2
3456789
10111213141516
17181920212223
24252627282930
31      

Most Popular Tags

Style Credit

Expand Cut Tags

No cut tags
Page generated Jan. 2nd, 2026 06:47 am
Powered by Dreamwidth Studios