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<div class="">Sajid,</div>
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I have also rested the simpler problem you provided. The branch hongzh/fix-computejacobian gives exactly the same numerical results as the master branch does, but runs much faster. So the solver seems to work correctly.
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<div class="">To rule out the possible compiler issues, you might want to try a different compiler or different optimization flags. Also you might want to try smaller stepsizes.</div>
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<div class="">Hong
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<div class="">On May 20, 2019, at 4:47 PM, Sajid Ali <<a href="mailto:sajidsyed2021@u.northwestern.edu" class="">sajidsyed2021@u.northwestern.edu</a>> wrote:</div>
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<div class="">Hi Hong, <br class="">
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I tried running a simpler problem that solves the equation ` <span class="gmail-pl-c">
u_t = A*u_xx + A*u_yy; </span>` and the fix-computejacobian branch works for this on a coarse grid. The code for the same is here :
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https://github.com/s-sajid-ali/xwp_petsc/blob/master/2d/FD/free_space/ex_dmda.c</a> and it requires no input file. It writes at all times steps and comparing the output at the last time step, everything looks fine.
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I want to eliminate a possible source of error which could be the fact that I installed both versions (3.11.2 and fix-computejacobian) with intel compilers and O3. Could floating point errors occur due to this ? I didn't specify -fp-model strict but since the
results I got were reasonable I never bothered to run a test suite. <br class="">
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Thank You, <br class="">
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<div style="font-size:12.8px" class="">Sajid Ali<br class="">
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<div style="font-size:12.8px" class="">Applied Physics<br class="">
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<div style="font-size:12.8px" class="">Northwestern University</div>
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