[yt-users] integrated quantities in cylindrical

[Suoqing Ji]

Sorry, the previous code is a kind of mixed up…

        @derived_field(name = "CylCellVolume")
        def CylCellVolume(field, data):
                return data["dx"]*data["dy"]*2*math.pi*data["x"]

        @derived_field(name = "CylCellMass")
        def CylCellMass(field, data):
                return data["CylCellVolume"]*data["Density"]

Best wishes.
Suoqing

On Jun 18, 2013, at 1:00 PM, Suoqing Ji wrote:

> Hi Roman,
> 
> I assume the quantity 'CylindricalCellMass' is a derived field defined by yourself? I usually define the 2d cylindrical cell volume as followings:
> 
>        @derived_field(name = "CylCellVolume") # CellVolume in yt is wrong
>        def realVolume(field, data):
>                return data["dx"]*data["dy"]*2*math.pi*data["x"]
> 
>        @derived_field(name = "CylCellMass")
>        def realCellMass(field, data):
>                return data["CylCellVolume"]*data["Density"]
> 
> And for my data set, the output given by YT (use dd.quantities['TotalQuantity']('CylCellMass')[0]) and FLASH subroutine (IO_writeIntegralQuantities) match down to the machine accuracy.
> 
> Best wishes,
> Suoqing
> 
> 
> On Jun 18, 2013, at 12:46 PM, Roman Yurchak wrote:
> 
>> Hello,
>> 
>> I'm interested in getting some integrated quantities from a cylindrical
>> 2d FLASH simulation.
>> 
>> Just to be sure, I started by comparing the total simulation mass
>> computed by yt ( with pf.h.all_data().quantities['TotalQuantity'] etc.)
>> and the one provided in FLASH logs, and the results are rather different
>> [see attachment]:
>> * _Values_:  difference of up 8% between the two methods
>> * _Time evolution_: total mass is decreasing in time according to
>> FLASH (which is ok with open boundary conditions) but it is increasing
>> with the yt's integration.
>> * _Sensitivity to resolution_: there are jumps in total density given
>> by yt for the time steps where the maximum refinement level is manually
>> decreased.
>> 
>> Would anyone know what might be the reason for this behaviour?
>> 
>> Just in case, I tried to do a second order integration instead of simply
>> summing the values in all the cells, but if didn't make an error, the
>> correction was negligible.
>> 
>> I can provide data and the yt script I'm using by PM if some could look
>> into this.
>> 
>> Thank you,
>> Regards,
>> -- 
>> Roman Yurchak
>> <integrated_quantities_FLASH_cyl.txt>_______________________________________________
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>