Alignment tool 'Cannot Thread', cutpoints, and memory effect
|Opened on:||Tuesday, May 1, 2012 - 14:37|
|Last modified:||Wednesday, May 2, 2012 - 20:12|
In the blog post for Apr. 30, I asked about the conditions for successful / failed thread. You can answer that here. But I'm really posting to point out that I've confirmed the memory effect! It's from the cutpoints.
On puzzle 550, pick 3kgrA and turn threading on. Then slide H 36 three slots to the right. The slide the other end of that block K 54, three slots to the left. Intuition says I'm back where I started but it has stopped threading. Even if I hit reset alignment, it won't thread! I think this has been causing a lot of my frustration.
The problem is that subsequence acquired a cutpoint when it first entered the gap at template V 31, and refused to thread after that. To make it align, I have to continue to my desired alignment, close cutpoints, and toggle threading on/off.
It looks like continuous threading is incompatible with the cutpoints. It was a neat idea. Before cutpoints, it would just resume threading whenever the alignment was acceptable. With cutpoints, threading has to be one-shot.
I would suggest a three-state threading button. Click to thread once (smileyface!) and then it turns off. Double-click to lock threading on. Click that to turn it off.