[Numpy-discussion] Some help on matlab to numpy translation
josef.pktd at gmail.com
josef.pktd at gmail.com
Mon Mar 15 18:53:12 EDT 2010
On Mon, Mar 15, 2010 at 5:58 PM, Nicolas Rougier
<Nicolas.Rougier at loria.fr> wrote:
>
>
> Thanks and in fact, I already wasted quite some time on and your last version will help me a lot. Unfortunately, I'm not a specialist at lattice Boltzmann methods at all so I'm not able to answer your questions (my initial idea was to convert the matlab script to be have a running example to get some starting point). Also, I found today some computers in the lab to test the matlab version and it seems to run as advertised on the site. I now need to run both versions side by side and to check where are the differences. I will post sources as soon as I get it to run properly.
>
> Thanks again.
>
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> Nicolas
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> On Mar 15, 2010, at 22:32 , Friedrich Romstedt wrote:
>
>> Ok, so I send yet another version. Maybe Bruce is right, but I didn't
>> care, because we have fret enough. Now it not only computes
>> something, but also displays something :-(
>>
>> Nicolas, maybe you can now waste some of your time with it? I was
>> curious, both to understand and to get it working, but I failed. I
>> doubt especially the section "Microscopic boundary conditions",
>> because commenting it out makes things, well, say worser. Leaving the
>> other sections out is also not recommendable, but at least not that
>> destructive. I do not understand why in the microscopic boundary
>> section only directions 6 and 7 come into play and not 3. Also I do
>> not understand why they occur in *all* output direction expressions.
>>
>> Furthermore, the fluid, albeit behaving also at the inlet quite
>> strange, bounces back the outlet ...
>>
>> I disabled the obstacle so far, and plotted the 4 direction
>> (downwards), and the resulting ux and uy flows.
>>
>> I give up so far.
>>
>> Friedrich
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I'm surprised you can translate matlab without have dot products
showing up all over.
I didn't really look at the code, but aren't these dot products ?
# % COLLISION STEP
# for i=1:9
# cu = 3*(cx(i)*ux+cy(i)*uy);
I usually put print shape/size inside the code for debugging until I'm
sure about correct shapes
Josef
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