The reason the answers are getting closer together when you add more bins is that you are decreasing the number of points in each bin, and as you do that the difference between mean(f * g) and mean(f) * mean(g) will get smaller, though it will not be identical until you have exactly one cell in each bin.
On Mon, Jan 27, 2014 at 5:29 PM, Stefano Bovino poetaste@gmail.com wrote:
Ah ok, it seems that increasing a lot the number of bins the two approaches are matching better... is there any reason for that?
A second question: how it works for the electrons? In enzo the electrons are usually initialized considering a factor of mp/me, YT takes into account this rescaling?
Thanks again Stefano
On Mon, Jan 27, 2014 at 6:24 PM, Stefano Bovino poetaste@gmail.comwrote:
ah... I'm binning, it also depends on the number of bins I'm using, but the discrepancy (slight) is still there):
prof3 = BinnedProfile1D(sph3, 64, "Radiuspc", 1.0e-6, 1.0e6)
In my initial setup I'm using a box of 300 pc.
Stefano
On Mon, Jan 27, 2014 at 6:20 PM, Stefano Bovino poetaste@gmail.comwrote:
Hi Matt, thanks for the quick reply. I'm using simple data from the enzo Collapse Test (27). It seems is mainly related to the size of the sphere I'm taking... but I don't know.
Here following a piece of my script:
pf3=load("DD0003/DD0003") c3= pf3.h.find_max("Density")[1] sph3 = pf3.h.sphere(c3, (100, 'pc')) prof3.add_fields("H2I_Density") prof3.add_fields("H2I_Fraction") prof3.add_fields("Radius")
... ...
d_ax2.loglog(prof3['Radius'], prof3['H2I_Density']/prof3['Density'], lw=1.5, linestyle='--', color='r') d_ax2.loglog(prof3['Radius'], prof3['H2I_Fraction'], lw=1.5, linestyle=':', color='y')
Thanks in advance Stefano
On Mon, Jan 27, 2014 at 6:11 PM, Matthew Turk matthewturk@gmail.comwrote:
On Mon, Jan 27, 2014 at 12:14 PM, poetaste@gmail.com < poetaste@gmail.com> wrote:
Hi Guys, I did a simple test with enzo and I tried to plot a radial profile of
the
chemical species fractions with YT.
The problem is that if I use the YT function which intrinsically plot
the
fraction for a species, let's say H2I_Fraction (as usual), and
compare this
with a direct evaluation of the mass fraction:
data['H2I_Density']/data['Density']
I obtain some slightly different results, mostly at large radii.
Anyone might explain this discrepancy!? This happens with all the
species.
Without knowing what "data" here is, or how you generated it, it's tough to say.
-Matt
Thank you in advance Stefano_______________________________________________ yt-users mailing list yt-users@lists.spacepope.org http://lists.spacepope.org/listinfo.cgi/yt-users-spacepope.org
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