Development/cabb-upgrade/PGFLAG

Specification

We want a simple PGPLOT-based utility to

• display UV data from a single baseline, in the format
  • channel number on X axis
  • time on Y axis
  • amplitude or phase shown as "greyscale"
• display a cursor with 'live' readback of the amplitude/phase, channel number, frequency and timestamp

We want to use this to select subsets of the displayed data and apply flagging commands to the subset.

Display characteristics:

• display one baseline at a time
• we want to be able to jump to a different baseline number (forward and back thro' the sequence)
• don't average time steps by default (make the averaging a command parameter)
• do sum the channels such that the entire bandpass fits in the PGPLOT display window (allow turning this off via command line params)
• if the uvdata array extends beyond the edges of the display window, allow scrolling (vertically or horizontally)
• when it is possible to scroll, show an arrow (outside the display grid) (with the shortcut key letter shown as well ?)
• arrow keys are the most obvious shortcut key!
• the cursor would ideally be an 'open plus' shape - lines extending to the edge of the display grid but with a small open area at the intersection so you can see what is directly under the cursor.
• zooming - allow zooming up to 1:1 display. May be useful to have higher zooms than this?
• must support SELECT and LINE keywords

Flagging:

• when user selects a piece of data, and says 'flag it'
  • update the display to show the data flagged away
  • allow 'undo' of the last flagging command.
• selection:
  • by area (PGPLOT boxing)
  • this will do single rows and columns as well.
• should be able to abort a flagging session, ie throw all flags for the current baseline.
• probably want to use temporary flagging files that only replace the flag file for the dataset at the end of the task
• probably want to allow logging of the flagging commands so they can be played back/edited with UVFLAG

---

Development?