On Mon, 31 May 2010, Edward Chapin wrote:
> SCUBA-2 analysis produces some huge data cubes, so I am accustomed to
> long file load times. However, I've recently produced a cube that just
> seems to sit there with "gaia_wish" running 100% when I try to load it
> up.
>
> Download this file:
>
> http://www.physics.ubc.ca/~echapin/scuba2/dks_compressed.sdf
>
> and then run up
>
> $ smurf
>
> and
>
> $ sc2expandmodel dks_compressed dks
>
> and finally
>
> $ gaia dks
>
> I get the initial gaia loading window (which then promptly disappears),
> and then I don't see anything else. The process is clearly doing
> something, but it takes several minutes for the main window to appear,
> and it is still "thinking" -- i.e. hourglass still turning, and no 2d
> plane that I can click on to get the spectral plot for the 3rd
> dimension. Finally after 8 min. it loads.
>
> I've looked at other data cubes with identical dimensions and don't have
> this problem (they load in seconds instead of minutes).
>
> I had been messing with the WCS information for the data cube, but KAPPA
> linplot on individual detectors doesn't seem to have a problem.
Hi Ed,
this is a known problem area for GAIA. What you've got is a mapping that
is using a lookup table for the 54000 coordinates in your third dimension.
To pass these around in the Skycat layers it is necessary to feed these
into and back out of a FITS encoding, that's where all the time is going.
The best way around this is to use a linear mapping if you can.
Cheers,
Peter.
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