Analog to FITSFigure.recenter?

[keflavich]

Is there a good analog to aplpy.FITSFigure's recenter functionality, i.e. a recommended way to programatically recenter and zoom using the WCS?

[keflavich]

This is still a significant reason I don't want to switch from aplpy

[astrofrog]

Ok, I'm now thinking of adding a helper function in WCSAxes to do this - it would look something like

def recenter_celestial(axes, skycoord, radius=None, width=None, height=None):
    ...

then if you want to recenter, you can do:

recenter_celestial(ax, SkyCoord(...), radius=3 * u.arcmin)

The reason for not making it a method is that in that form it only really applies to celestial coordinate systems. I'm still trying to think what width and height should mean if the celestial axes are not aligned with the pixel axes.

[keflavich]

@astrofrog - how would you accomplish this in wcsaxes at present? I'm having an extremely hard time getting wcsaxes to do anything sensible, since ax.axis doesn't accept a transform keyword.

I ended up having to do something really awful like this:

tr_pix = ax.get_transform("pixel")
xmin,xmax,ymin,ymax = [266.8318615-0.062/2, 266.8318615+0.062/2, -28.3940598-0.105/2, -28.3940598+0.105/2]
xmin_,ymin_ = mywcs.wcs_world2pix(xmin, ymin, 0) #tr_pix.transform([xmin,ymin])
xmax_,ymax_ = mywcs.wcs_world2pix(xmax, ymax, 0) #tr_pix.transform([xmax,ymax])
ax.axis([xmin_,xmax_,ymin_,ymax_])

where tr_pix.transform did not work (it returned identical values for the "max" and "min" points)