Tuesday, July 14, 2009

Contoured Density Plots

Started off the day going over isochrone images with Beth

The Besancon Model still seems puzzling, showing a lot of faint red stars. The Trilegal looks better, and the isochrone fitted at 20kpc nearly follows the line of stars (great by my standards, since in my limited experience few things have lined up nearly this well, but Beth mentioned some discrepancies). We determined that the disk/halo stars cut-off should be at a v-i of 1.5.
I haven't yet started working the separated stars yet, as I got distracted today...

Distribution, smoothing, significance

Brainstorming ensues. Beth explained how the smoothing worked a little bit, which brought up some minor pixel issues. To get out the edges and contrasts we wanted, I used SEARCH2D to make a pixel map of just 1's and 0's to separate the outer area with no data. The significance ((image-mean)/stddev) was taken of the data, and plotted with the "nodata" area set to 0.0 on the grey-scale. I also made an accompanying histogram of n-sigma; it wasn't Gaussian but it had the right tailing-off-shape.

Went to talk on BLAST-thought it was cool

Contour lines

Adding to the distribution density plot are now contour lines. It took me pretty much all afternoon figuring out and working on the code from Beth to make these show up properly. In the end, with a little typo-spotting help from Gail, I got it to work. I even patted myself on the back a little for going back making the contour lines shift from black to white so that you could still distinguish them on the lighter and darker areas. Only problems are the axes... even more so when I tried to make another plot of the northern field (as I'd been working primarily with the southern one all day, and didn't want the poor guy to feel neglected).

(in no particular order)
Fixing axes

-Go through code again and see if I can't find the problem
-If not, talk to Beth about it
Implement color-cut
Random distribution generator

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