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Thanks, Hong. That’s exactly what I need. <br class="">
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<div class="">On Mar 5, 2022, at 11:55 AM, Zhang, Hong <<a href="mailto:hongzhang@anl.gov" class="">hongzhang@anl.gov</a>> wrote:</div>
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<div class="">You can control the factors with</div>
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<div class=""><b class="">-ts_adapt_clip <low>,<high></b>- to set admissible time step decrease and increase factors</div>
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<div class="">The default setting uses low=0.1, high=10.</div>
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<a href="https://urldefense.com/v3/__https://petsc.org/release/docs/manualpages/TS/TSAdaptSetClip.html*TSAdaptSetClip__;Iw!!HXCxUKc!m-lJp6aSKp23rrCtOhTe5dlbe4g0ZsN_lEboynDzYQjVwitW64j-4SARMU4MSw$" class="">https://petsc.org/release/docs/manualpages/TS/TSAdaptSetClip.html#TSAdaptSetClip</a><br class="">
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<div class="">Hong (Mr.)</div>
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<div class="">On Mar 5, 2022, at 12:26 PM, Tang, Qi <<a href="mailto:tangqi@msu.edu" class="">tangqi@msu.edu</a>> wrote:</div>
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<div class="">Hi,<br class="">
Is there a simple way to control the first few adaptive time step? Currently, I am using the following options but dt grows too fast initially. The first few time steps increase dt by a factor of 10 in each time step. Is there a way to do a slow start, say,
 a factor of 2 instead of 10? Thanks.<br class="">
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-ts_type arkimex<br class="">
-ts_arkimex_type 2e<br class="">
-ts_arkimex_fully_implicit <br class="">
-ts_adapt_dt_min 1.0e-5 <br class="">
-ts_adapt_dt_max 1.0e-2 <br class="">
-ts_adapt_type basic<br class="">
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Qi<br class="">
T-5@LANL</div>
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