Subject: "sticky" crosshairs/placeholders
From: nickfitzkee
Date: Jul 16, 2009

Next: 593


Hi everyone,

Im wondering if theres a way to make the crosshair/reticle in sparky
sticky. In other words, I would like to mark the expected position of
a particular cross-peak while I scan through the planes of a 3-D
spectrum with the mouse. That sounds a little odd, so here are two
examples of what I mean:

3D HHN NOE spectrum: by placing the crosshairs at the expected 1H-1H
position of an NOE cross peak, I would like to scan through N planes to
find the corresponding spin system.

HNCA spectrum: by placing the crosshairs on a CA(i) peak, I would like
to scan through the N planes to find possible CA(i-1) peaks along the
horizontal axis.

Currently, if I know of two ways to scan through N planes while keeping
the crosshairs fixed: (1) use zu/zd accelerators, which is cumbersome
for a 512 plane spectrum. (2) tape a ruler to my monitor so I can click
through N planes (my colleague uses a post-it note).

In CARA, the crosshairs dont follow the mouse (which has its own
disadvantages), but it makes this problem trivial. Even in NMRDraw, one
can hack a solution by viewing a horizontal 1-D slice and scaling the
spectrum down to zero. But Ive not found a way to solve this problem
in Sparky. I thought maybe a screen ruler application would be helpful,
but so far I havent found a good one for linux. Anyone else found a
good way around this problem?

Regards,
Nick