<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div><br></div> See, for example <a href="https://petsc.org/release/docs/manualpages/TS/TSTrajectoryGetVecs/">https://petsc.org/release/docs/manualpages/TS/TSTrajectoryGetVecs/</a> and <a href="https://petsc.org/release/docs/manualpages/TS/TSTrajectoryGetUpdatedHistoryVecs/">https://petsc.org/release/docs/manualpages/TS/TSTrajectoryGetUpdatedHistoryVecs/</a> <div><br></div><div> One does not directly access the data inside the trajectory; one calls functions in the API to obtained desired information. If you need specific information that it does not currently provide we can attempt to provide additional functionality.</div><div><br></div><div><br></div><div> Barry</div><div><br><div><br><blockquote type="cite"><div>On Dec 14, 2022, at 1:07 PM, Guglielmo, Tyler Hardy via petsc-users <petsc-users@mcs.anl.gov> wrote:</div><br class="Apple-interchange-newline"><div><meta charset="UTF-8"><div class="WordSection1" style="page: WordSection1; caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 18px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">Thanks Matt,<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"><o:p> </o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">I’m a bit confused on where the trajectory is being stored in the TSTrajectory object.<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"><o:p> </o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">Basically I have run<span class="Apple-converted-space"> </span><o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"><o:p> </o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">TSSetSaveTrajectory(ts);<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">…<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">TSSolve(ts, x);<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">TSTrajectory tj;<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">TSGetTrajectory(ts, &tj);<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">TSTrajectorySetType(tj, ts, TSTRAJECTORYMEMORY);<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"><o:p> </o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">How is the object supposed to be accessed to find the entire trajectory? I couldn’t find a clear example of where this is laid out in the documentation.<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"><o:p> </o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">The TSTrajectory object looks like some complicated struct, but parsing which pointer is pointing to the solution has alluded me.<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"><o:p> </o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">Thanks for your time!<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"><o:p> </o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">Best,<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">Tyler<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"><o:p> </o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"><o:p> </o:p></span></div><div style="border-style: solid none none; border-top-width: 1pt; border-top-color: rgb(181, 196, 223); padding: 3pt 0in 0in;"><p class="MsoNormal" style="margin: 0in 0in 12pt; font-size: 10pt; font-family: Calibri, sans-serif;"><b><span style="font-size: 12pt;">From:<span class="Apple-converted-space"> </span></span></b><span style="font-size: 12pt;">Matthew Knepley <<a href="mailto:knepley@gmail.com" style="color: blue; text-decoration: underline;">knepley@gmail.com</a>><br><b>Date:<span class="Apple-converted-space"> </span></b>Tuesday, December 13, 2022 at 6:41 AM<br><b>To:<span class="Apple-converted-space"> </span></b>Guglielmo, Tyler Hardy <<a href="mailto:guglielmo2@llnl.gov" style="color: blue; text-decoration: underline;">guglielmo2@llnl.gov</a>><br><b>Cc:<span class="Apple-converted-space"> </span></b><a href="mailto:petsc-users@mcs.anl.gov" style="color: blue; text-decoration: underline;">petsc-users@mcs.anl.gov</a><span class="Apple-converted-space"> </span><<a href="mailto:petsc-users@mcs.anl.gov" style="color: blue; text-decoration: underline;">petsc-users@mcs.anl.gov</a>><br><b>Subject:<span class="Apple-converted-space"> </span></b>Re: [petsc-users] Saving solution with monitor function<o:p></o:p></span></p></div><div><div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">On Tue, Dec 13, 2022 at 8:40 AM Guglielmo, Tyler Hardy via petsc-users <<a href="mailto:petsc-users@mcs.anl.gov" style="color: blue; text-decoration: underline;">petsc-users@mcs.anl.gov</a>> wrote:<o:p></o:p></span></div></div><div><blockquote style="border-style: none none none solid; border-left-width: 1pt; border-left-color: rgb(204, 204, 204); padding: 0in 0in 0in 6pt; margin-left: 4.8pt; margin-right: 0in;"><div><div><div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">Hi all,<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"> <o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">I am a new PETSc user (and new to MPI in general), and was wondering if someone could help me out with what I am sure is a basic question (if this is not the appropriate email list or there is a better place please let me know!).<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"> <o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">Basically, I am writing a code that requires a solution to an ODE that will be used later on during runtime. I have written the basic ODE solver using TSRK, however I haven’t thought of a good way to store the actual solution at all time steps throughout the time evolution. I would like to avoid writing each time step to a file through the monitor function, and instead just plug each time step into an array.<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"> <o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">How is this usually done? I suppose the user defined struct that gets passed into the monitor function could contain a pointer to an array in main? This is how I would do this if the program wasn’t of the MPI variety, but I am not sure how to properly declare a pointer to an array declared as Vec and built through the usual PETSc process. Any tips are greatly appreciated<o:p></o:p></span></div></div></div></div></blockquote><div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"><o:p> </o:p></span></div></div><div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">I think this is what TSTrajectory is for. I believe you want <a href="https://urldefense.us/v3/__https:/petsc.org/main/docs/manualpages/TS/TSTRAJECTORYMEMORY/__;!!G2kpM7uM-TzIFchu!irkbXWpYDosRslumKjVGCqxHkKyU-riye4i1dWe58HYH_sFxImRj33gOkhB2sgd_duk$" style="color: blue; text-decoration: underline;">https://petsc.org/main/docs/manualpages/TS/TSTRAJECTORYMEMORY/</a><o:p></o:p></span></div></div><div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"><o:p> </o:p></span></div></div><div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"> Thanks,<o:p></o:p></span></div></div><div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"><o:p> </o:p></span></div></div><div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"> Matt<o:p></o:p></span></div></div><div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"> <o:p></o:p></span></div></div><blockquote style="border-style: none none none solid; border-left-width: 1pt; border-left-color: rgb(204, 204, 204); padding: 0in 0in 0in 6pt; margin-left: 4.8pt; margin-right: 0in;"><div><div><div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">Thanks for your time,<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">Tyler<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"> <o:p></o:p></span></div><div><div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">+++++++++++++++++++++++++++++<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">Tyler Guglielmo<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">Postdoctoral Researcher<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">Lawrence Livermore National Lab<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">Office: 925-423-6186<o:p></o:p></span></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">Cell: 210-480-8000<o:p></o:p></span></div></div></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">+++++++++++++++++++++++++++++<o:p></o:p></span></div></div></div></div></blockquote></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"><br clear="all"><o:p></o:p></span></div><div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"><o:p> </o:p></span></div></div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">--<span class="Apple-converted-space"> </span><o:p></o:p></span></div><div><div><div><div><div><div><div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;">What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>-- Norbert Wiener<o:p></o:p></span></div></div><div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"><o:p> </o:p></span></div></div><div><div style="margin: 0in; font-size: 10pt; font-family: Calibri, sans-serif;"><span style="font-size: 11pt;"><a href="https://urldefense.us/v3/__http:/www.cse.buffalo.edu/*knepley/__;fg!!G2kpM7uM-TzIFchu!irkbXWpYDosRslumKjVGCqxHkKyU-riye4i1dWe58HYH_sFxImRj33gOkhB27-uscIw$" target="_blank" style="color: blue; text-decoration: underline;">https://www.cse.buffalo.edu/~knepley/</a></span></div></div></div></div></div></div></div></div></div></div></div></blockquote></div><br></div></body></html>