Re: [Libmesh-users] Select quadrature rule order based on element type

[Yuxiang W. <yw...@vi...>]

Dear Vikram,

Thank you again for the pointer (and the patience)! I used the PerfLog
class and compared. As you mentioned, the assembly time change is quite
small (1.8772 vs 1.8845 sec).

And I appreciate your suggestion for checking directly on the type of
element as well!

Have a great week ahead,
Shawn

PS the complete timing report:

Before including the qrule creation in the loop:
 ------------------------------------------------------------------------------------------------------------
| Assemble Performance: Alive time=1.88073, Active time=1.87716
                                  |
 ------------------------------------------------------------------------------------------------------------
| Event                         nCalls     Total Time  Avg Time    Total
Time  Avg Time    % of Active Time  |
|                                          w/o Sub     w/o Sub     With
Sub    With Sub    w/o S    With S   |
|------------------------------------------------------------------------------------------------------------|
|
                                  |
| Entire assembly               1          1.8772      1.877163    1.8772
    1.877163    100.00   100.00   |
 ------------------------------------------------------------------------------------------------------------
| Totals:                       1          1.8772
                100.00            |
 ------------------------------------------------------------------------------------------------------------

After including the qrule creation in the loop:

------------------------------------------------------------------------------------------------------------
| Assemble Performance: Alive time=1.88795, Active time=1.88449
                                  |
 ------------------------------------------------------------------------------------------------------------
| Event                         nCalls     Total Time  Avg Time    Total
Time  Avg Time    % of Active Time  |
|                                          w/o Sub     w/o Sub     With
Sub    With Sub    w/o S    With S   |
|------------------------------------------------------------------------------------------------------------|
|
                                  |
| Entire assembly               1          1.8845      1.884490    1.8845
    1.884490    100.00   100.00   |
 ------------------------------------------------------------------------------------------------------------
| Totals:                       1          1.8845
                100.00            |
 ------------------------------------------------------------------------------------------------------------

On Sun, Apr 14, 2019 at 4:11 PM Vikram Garg <vik...@gm...> wrote:

> Hi Yuxiang, glad to hear you are getting the expected results. This change
> looks correct for your case and should not affect the assembly time by a
> significant amount. You could also check for the actual type of element
> (QUAD4 or TRI) instead of checking indirectly via the number of nodes.
>
> You can check the performance change by checking the performance log which
> is included at the end of the program's output. Look for something like:
>
> | System                                                                                                          |
> |   assemble()                       1          0.0014      0.001422    0.0028      0.002767    17.59    34.22    |
>
> Thanks.
> Vikram Garg
>
> vikramvgarg.github.io/
>
>
> On Sun, Apr 14, 2019 at 5:22 PM Yuxiang Wang <yw...@vi...> wrote:
>
>> Hi Vikram,
>>
>> Thank you for your response!
>>
>> I didn't think about that - I tried to add that inside the loop over
>> elements and got the correct results!
>>
>> Question - do you think that will significantly slow down the assembly,
>> because we are now creating qrule and attaching it for every element loop?
>>
>> What I did was the following:
>>
>> for (const auto & elem : mesh.active_local_element_ptr_range()) {
>>
>> const unsigned int n_nodes = elem->n_nodes();
>>
>> Order qrule_order;
>>
>> switch (n_nodes)
>> {
>> case 3:
>> qrule_order = SECOND;
>> break;
>>
>> case 4:
>> qrule_order = THIRD;
>> break;
>>
>> default:
>> qrule_order = fe_type.default_quadrature_order();
>> break;
>> }
>>
>> QGauss qrule (dim, qrule_order);
>> fe->attach_quadrature_rule (&qrule);
>>
>> Thanks!
>>
>> Best,
>> Shawn
>>
>> On Sun, Apr 14, 2019 at 2:53 PM Vikram Garg <vik...@gm...>
>> wrote:
>>
>>> Hi Yuxiang,
>>>                    It should be possible to move the construction of the
>>> finite element and the specification of the quadrature rule inside the loop
>>> over elements. Did this give any errors, or is otherwise unfeasible for
>>> performance reasons ?
>>>
>>> Thanks.
>>> Vikram Garg
>>>
>>> vikramvgarg.github.io/
>>>
>>>
>>> On Sun, Apr 14, 2019 at 4:30 PM Yuxiang Wang <yw...@vi...> wrote:
>>>
>>>> Dear all,
>>>>
>>>> Sorry for the spam.
>>>>
>>>> I have a mix of QUAD4 and TRI3 elements in my mesh, and would like to
>>>> use
>>>> different quadrature rule orders for each type. Specifically, I'd like
>>>> to
>>>> have order THIRD for QUAD4 and SECOND for TRI3. By default, the orders
>>>> are
>>>> both THIRD.
>>>>
>>>> In most examples, I noticed that the specification of qrule is only for
>>>> the
>>>> entire FEType and not dependent on the element type (e.g. QUAD4 vs
>>>> TRI3).
>>>> Could you please share with me some hints on how to make
>>>> element-dependent
>>>> qrule order selection happen?
>>>>
>>>> Best,
>>>> Shawn
>>>>
>>>>
>>>> --
>>>> Yuxiang "Shawn" Wang, PhD
>>>> yw...@vi...
>>>> +1 (434) 284-0836
>>>>
>>>> _______________________________________________
>>>> Libmesh-users mailing list
>>>> Lib...@li...
>>>> https://lists.sourceforge.net/lists/listinfo/libmesh-users
>>>>
>>>
>>
>> --
>> Yuxiang "Shawn" Wang, PhD
>> yw...@vi...
>> +1 (434) 284-0836
>>
>

-- 
Yuxiang "Shawn" Wang, PhD
yw...@vi...
+1 (434) 284-0836