Monday, June 8, 2009


So I've been getting ready to run which Dave sent me on Friday. It's a different way of doing the matching. That code requires that the input catalogs of star coordinates are sorted by RA. So, I wrote some code that sorts the RA's and spits out files which contain the RA and Dec coords in order.

I then tried to run the code. I think my problem is that when I write the files they don't come out looking like 11 different columns. It prints out as only 5 columns across. I think this is confusing Python when I try to read in the file. I used two different techniques for writing the files...forprint and printf and both turned out a files that looked the same. Not totally sure how to fix this, but I think I'll do some googling tonight and have some ideas before tomorrow morning.

I also started working on the CMD calibration code. I'm still confused about how to calculate the saturation limit. I have so far worked on the part of the code that will match SDSS stars to Willman 1 stars. However, I'll need a new SDSS catalog that takes into account the saturation limit on the KPNO data. My next step is to make the zero-point offset plot (g_true-g_inst vs. g_inst). The other big thing I haven't figured out yet is how to weight the points by their measurement uncertainties.

Finally, I sent Dave the image files so hopefully they got there alright and he can give some input in the near future about problems I've overlooked. Also, still brainstorming on things that could be wrong with the data, I read something online at that for the more complicated analytical models DAOphot uses for its psfs, the more stars are needed to define it. I was picking 75 stars. Is this enough?

1. Figure out file-writing issue and run
2. Make some more headway on CMD calibration--saturation limits and weighting points.
3. Maybe talk to Dave about those images if he's figured anything out yet.

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