[yt-users] Halos on slices

[Matthew Turk]

Hi Shankar,

> 1. I did pc.add_slice("Density",0). Now, I want to plot the halos just for that slice. Is it possible to plot the Halos (from HaloAnalysis.out) slice wise ?

Yes, but it is not built in.  You will have to write a callback that
checks which halos a slice intersects with and then plots them.  You
can use the yt/raven/Callbacks.py module as a starting point.  When
you have finished, please submit a patch so that we can include it in
the main distribution.

>
> 2. I added the Density contours on the slice like...
>
>   p.modify["contour"]("Density",ncont=4,take_log=False,clim=(1e-28,1e-30))
>
>
> Here, if I am correct, the (1e-28,1e-30) range is divided into 4 equal intervals. So, would the contours be (1e-28,7.525e-29,5.05e-29, 2.575e-29, 1e-30) ? And which of these 5 will get plotted  (the first 4? or the last 4?)

The contours are generated via linspace.  You have selected not to log
them, so they are calculated as such:

In [3]: na.linspace(1e-28, 1e-30, 4)
Out[3]:
array([  1.00000000e-28,   6.70000000e-29,   3.40000000e-29,
         1.00000000e-30])

Your plot is consistent with this.

-Matt