"You know the number of cells if you can read connectivity. Do you mean that the format does not tell you the number of vertices?"
Sort of... So, the format does provide the number of vertices, however, due to the way I read the data in parallel I don't know immediately how many local vertices there will be. Which prevents me from knowing the chart a priori. I figured out the number of vertices using PetscHashSetI to determine the number of unique entries in the connectivity list. ________________________________ From: Matthew Knepley <knep...@gmail.com> Sent: Wednesday, May 1, 2024 8:52 PM To: Ferrand, Jesus A. <ferra...@my.erau.edu> Cc: petsc-users@mcs.anl.gov <petsc-users@mcs.anl.gov> Subject: Re: [EXTERNAL] Re: [petsc-users] Is there anything like a "DMPlexSetCones()" ? On Wed, May 1, 2024 at 4:23 PM Ferrand, Jesus A. <ferra...@my.erau.edu<mailto:ferra...@my.erau.edu>> wrote: Matt: My bad again, I need to clarify something that I just realized doesn't make sense. I said: "The nature of the I/O makes it so that I need to read the connectivity before I get a semblance of buffer sizes." Scratch that, obviously, if I can read the connectivity, I know the buffer sizes. What I should have said is that I cannot know the "chart" that one sets in DMPlexSetChart() a priori like in most cases. I need to determine the chart from the connectivity lists. You know the number of cells if you can read connectivity. Do you mean that the format does not tell you the number of vertices? Thanks, Matt ________________________________ From: Ferrand, Jesus A. <ferra...@my.erau.edu<mailto:ferra...@my.erau.edu>> Sent: Wednesday, May 1, 2024 8:17 PM To: Matthew Knepley <knep...@gmail.com<mailto:knep...@gmail.com>> Cc: petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov> <petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov>> Subject: Re: [EXTERNAL] Re: [petsc-users] Is there anything like a "DMPlexSetCones()" ? Matt: "I do not understand the "flag check". What is that?" My bad, I should have referred to the "dm->setupcalled". I believe this PetscBool is checked by the other DM (not just DMPlex) APIs. The subsequent checks for dm->setupcalled == PETSC_TRUE is what I meant to say. Here's a copy of DMSetUp(). PetscErrorCode<https://urldefense.us/v3/__https://petsc.org/release/manualpages/Sys/PetscErrorCode/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVa4H8D00$ > DMSetUp<https://urldefense.us/v3/__https://petsc.org/release/manualpages/DM/DMSetUp/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDV8IM749Q$ >(DM<https://urldefense.us/v3/__https://petsc.org/release/manualpages/DM/DM/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVgDhrMSM$ > dm) 817: { 818: PetscFunctionBegin<https://urldefense.us/v3/__https://petsc.org/release/manualpages/Sys/PetscFunctionBegin/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVnUPckbQ$ >; 820: if (dm->setupcalled) PetscFunctionReturn<https://urldefense.us/v3/__https://petsc.org/release/manualpages/Sys/PetscFunctionReturn/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVA6jIYzM$ >(PETSC_SUCCESS<https://urldefense.us/v3/__https://petsc.org/release/manualpages/Sys/PetscErrorCode/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVa4H8D00$ >); 821: PetscTryTypeMethod<https://urldefense.us/v3/__https://petsc.org/release/manualpages/Sys/PetscTryTypeMethod/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVj0O9HKI$ >(dm, setup); 822: dm->setupcalled = PETSC_TRUE<https://urldefense.us/v3/__https://petsc.org/release/manualpages/Sys/PETSC_TRUE/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVmrWLiyw$ >; 823: PetscFunctionReturn<https://urldefense.us/v3/__https://petsc.org/release/manualpages/Sys/PetscFunctionReturn/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVA6jIYzM$ >(PETSC_SUCCESS<https://urldefense.us/v3/__https://petsc.org/release/manualpages/Sys/PetscErrorCode/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVa4H8D00$ >); 824: } "We could make a DMPlexSetCones(), but as you point out, the workflow for DMSetUp() would have to change. Where does the memory come from for your connectivity?" It's a memory that I myself allocate based on a file's contents. The nature of the I/O makes it so that I need to read the connectivity before I get a semblance of buffer sizes. Otherwise, I would stick to the tried and tested way. Also, when replying to the PETSc developers, users must reply to petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov> and not just to the individual email accounts of the developers, right? ________________________________ From: Matthew Knepley <knep...@gmail.com<mailto:knep...@gmail.com>> Sent: Wednesday, May 1, 2024 8:07 PM To: Ferrand, Jesus A. <ferra...@my.erau.edu<mailto:ferra...@my.erau.edu>> Cc: petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov> <petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov>> Subject: [EXTERNAL] Re: [petsc-users] Is there anything like a "DMPlexSetCones()" ? CAUTION: This email originated outside of Embry-Riddle Aeronautical University. Do not click links or open attachments unless you recognize the sender and know the content is safe. On Wed, May 1, 2024 at 3:34 PM Ferrand, Jesus A. <ferra...@my.erau.edu<mailto:ferra...@my.erau.edu>> wrote: This Message Is From an External Sender This message came from outside your organization. Dear PETSc team: For a project that I'm working on, I need to manually build a DMPlex. >From studying the source code of the various APIs in which the plex is built >from some supported file format, I get that the workflow is this: 1. DMPlexSetChart() <-- Input nCells + nVerts 2. DMPlexSetConeSize() <-- Input ConeSize for each point in [0,nCells) 3. DMSetUp() – Allocates memory internally. 4. DMPlexGetCones() --> Gives you the memory onto which to write the cell connectivity. 5. *Write connectivity* 6. DMPlexReorderCell() <-- For each point in [0,nCells) I'm in a situation where the memory given by step (4) is available a-priori. I was hoping to skip steps 2, 3 , and 4 with something like a "DMPlexSetCones()", but such an API does not exist. My current workaround is to implement steps 2 through 4 as always and have double the memory allocated in the interim (my instance + DM's internal instance). I was thinking of looking for the name of the struct member and = it to my memory, but I can't overcome the flag check in DMSetUp() during later calls to DMPlexGetCones() or DMPlexGetTransitiveClosure(). I do not understand the "flag check". What is that? We could make a DMPlexSetCones(), but as you point out, the workflow for DMSetUp() would have to change. Where does the memory come from for your connectivity? Thanks, Matt Sincerely: J.A. Ferrand Embry-Riddle Aeronautical University - Daytona Beach - FL Ph.D. Candidate, Aerospace Engineering M.Sc. Aerospace Engineering B.Sc. Aerospace Engineering B.Sc. Computational Mathematics Phone: (386)-843-1829 Email(s): ferra...@my.erau.edu<mailto:ferra...@my.erau.edu> jesus.ferr...@gmail.com<mailto:jesus.ferr...@gmail.com> -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://urldefense.us/v3/__https://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVQRKJmPA$ <https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVu0P9fBI$ > ________________________________ From: Matthew Knepley <knep...@gmail.com<mailto:knep...@gmail.com>> Sent: Wednesday, May 1, 2024 8:07 PM To: Ferrand, Jesus A. <ferra...@my.erau.edu<mailto:ferra...@my.erau.edu>> Cc: petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov> <petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov>> Subject: [EXTERNAL] Re: [petsc-users] Is there anything like a "DMPlexSetCones()" ? CAUTION: This email originated outside of Embry-Riddle Aeronautical University. Do not click links or open attachments unless you recognize the sender and know the content is safe. On Wed, May 1, 2024 at 3:34 PM Ferrand, Jesus A. <ferra...@my.erau.edu<mailto:ferra...@my.erau.edu>> wrote: This Message Is From an External Sender This message came from outside your organization. Dear PETSc team: For a project that I'm working on, I need to manually build a DMPlex. >From studying the source code of the various APIs in which the plex is built >from some supported file format, I get that the workflow is this: 1. DMPlexSetChart() <-- Input nCells + nVerts 2. DMPlexSetConeSize() <-- Input ConeSize for each point in [0,nCells) 3. DMSetUp() – Allocates memory internally. 4. DMPlexGetCones() --> Gives you the memory onto which to write the cell connectivity. 5. *Write connectivity* 6. DMPlexReorderCell() <-- For each point in [0,nCells) I'm in a situation where the memory given by step (4) is available a-priori. I was hoping to skip steps 2, 3 , and 4 with something like a "DMPlexSetCones()", but such an API does not exist. My current workaround is to implement steps 2 through 4 as always and have double the memory allocated in the interim (my instance + DM's internal instance). I was thinking of looking for the name of the struct member and = it to my memory, but I can't overcome the flag check in DMSetUp() during later calls to DMPlexGetCones() or DMPlexGetTransitiveClosure(). I do not understand the "flag check". What is that? We could make a DMPlexSetCones(), but as you point out, the workflow for DMSetUp() would have to change. Where does the memory come from for your connectivity? Thanks, Matt Sincerely: J.A. Ferrand Embry-Riddle Aeronautical University - Daytona Beach - FL Ph.D. Candidate, Aerospace Engineering M.Sc. Aerospace Engineering B.Sc. Aerospace Engineering B.Sc. Computational Mathematics Phone: (386)-843-1829 Email(s): ferra...@my.erau.edu<mailto:ferra...@my.erau.edu> jesus.ferr...@gmail.com<mailto:jesus.ferr...@gmail.com> -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://urldefense.us/v3/__https://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVQRKJmPA$ <https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVu0P9fBI$ > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://urldefense.us/v3/__https://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVQRKJmPA$ <https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVu0P9fBI$ > ________________________________ From: Matthew Knepley <knep...@gmail.com> Sent: Wednesday, May 1, 2024 8:52 PM To: Ferrand, Jesus A. <ferra...@my.erau.edu> Cc: petsc-users@mcs.anl.gov <petsc-users@mcs.anl.gov> Subject: Re: [EXTERNAL] Re: [petsc-users] Is there anything like a "DMPlexSetCones()" ? On Wed, May 1, 2024 at 4:23 PM Ferrand, Jesus A. <ferra...@my.erau.edu<mailto:ferra...@my.erau.edu>> wrote: Matt: My bad again, I need to clarify something that I just realized doesn't make sense. I said: "The nature of the I/O makes it so that I need to read the connectivity before I get a semblance of buffer sizes." Scratch that, obviously, if I can read the connectivity, I know the buffer sizes. What I should have said is that I cannot know the "chart" that one sets in DMPlexSetChart() a priori like in most cases. I need to determine the chart from the connectivity lists. You know the number of cells if you can read connectivity. Do you mean that the format does not tell you the number of vertices? Thanks, Matt ________________________________ From: Ferrand, Jesus A. <ferra...@my.erau.edu<mailto:ferra...@my.erau.edu>> Sent: Wednesday, May 1, 2024 8:17 PM To: Matthew Knepley <knep...@gmail.com<mailto:knep...@gmail.com>> Cc: petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov> <petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov>> Subject: Re: [EXTERNAL] Re: [petsc-users] Is there anything like a "DMPlexSetCones()" ? Matt: "I do not understand the "flag check". What is that?" My bad, I should have referred to the "dm->setupcalled". I believe this PetscBool is checked by the other DM (not just DMPlex) APIs. The subsequent checks for dm->setupcalled == PETSC_TRUE is what I meant to say. Here's a copy of DMSetUp(). PetscErrorCode<https://urldefense.us/v3/__https://petsc.org/release/manualpages/Sys/PetscErrorCode/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVa4H8D00$ > DMSetUp<https://urldefense.us/v3/__https://petsc.org/release/manualpages/DM/DMSetUp/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDV8IM749Q$ >(DM<https://urldefense.us/v3/__https://petsc.org/release/manualpages/DM/DM/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVgDhrMSM$ > dm) 817: { 818: PetscFunctionBegin<https://urldefense.us/v3/__https://petsc.org/release/manualpages/Sys/PetscFunctionBegin/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVnUPckbQ$ >; 820: if (dm->setupcalled) PetscFunctionReturn<https://urldefense.us/v3/__https://petsc.org/release/manualpages/Sys/PetscFunctionReturn/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVA6jIYzM$ >(PETSC_SUCCESS<https://urldefense.us/v3/__https://petsc.org/release/manualpages/Sys/PetscErrorCode/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVa4H8D00$ >); 821: PetscTryTypeMethod<https://urldefense.us/v3/__https://petsc.org/release/manualpages/Sys/PetscTryTypeMethod/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVj0O9HKI$ >(dm, setup); 822: dm->setupcalled = PETSC_TRUE<https://urldefense.us/v3/__https://petsc.org/release/manualpages/Sys/PETSC_TRUE/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVmrWLiyw$ >; 823: PetscFunctionReturn<https://urldefense.us/v3/__https://petsc.org/release/manualpages/Sys/PetscFunctionReturn/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVA6jIYzM$ >(PETSC_SUCCESS<https://urldefense.us/v3/__https://petsc.org/release/manualpages/Sys/PetscErrorCode/__;!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVa4H8D00$ >); 824: } "We could make a DMPlexSetCones(), but as you point out, the workflow for DMSetUp() would have to change. Where does the memory come from for your connectivity?" It's a memory that I myself allocate based on a file's contents. The nature of the I/O makes it so that I need to read the connectivity before I get a semblance of buffer sizes. Otherwise, I would stick to the tried and tested way. Also, when replying to the PETSc developers, users must reply to petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov> and not just to the individual email accounts of the developers, right? ________________________________ From: Matthew Knepley <knep...@gmail.com<mailto:knep...@gmail.com>> Sent: Wednesday, May 1, 2024 8:07 PM To: Ferrand, Jesus A. <ferra...@my.erau.edu<mailto:ferra...@my.erau.edu>> Cc: petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov> <petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov>> Subject: [EXTERNAL] Re: [petsc-users] Is there anything like a "DMPlexSetCones()" ? CAUTION: This email originated outside of Embry-Riddle Aeronautical University. Do not click links or open attachments unless you recognize the sender and know the content is safe. On Wed, May 1, 2024 at 3:34 PM Ferrand, Jesus A. <ferra...@my.erau.edu<mailto:ferra...@my.erau.edu>> wrote: This Message Is From an External Sender This message came from outside your organization. Dear PETSc team: For a project that I'm working on, I need to manually build a DMPlex. >From studying the source code of the various APIs in which the plex is built >from some supported file format, I get that the workflow is this: 1. DMPlexSetChart() <-- Input nCells + nVerts 2. DMPlexSetConeSize() <-- Input ConeSize for each point in [0,nCells) 3. DMSetUp() – Allocates memory internally. 4. DMPlexGetCones() --> Gives you the memory onto which to write the cell connectivity. 5. *Write connectivity* 6. DMPlexReorderCell() <-- For each point in [0,nCells) I'm in a situation where the memory given by step (4) is available a-priori. I was hoping to skip steps 2, 3 , and 4 with something like a "DMPlexSetCones()", but such an API does not exist. My current workaround is to implement steps 2 through 4 as always and have double the memory allocated in the interim (my instance + DM's internal instance). I was thinking of looking for the name of the struct member and = it to my memory, but I can't overcome the flag check in DMSetUp() during later calls to DMPlexGetCones() or DMPlexGetTransitiveClosure(). I do not understand the "flag check". What is that? We could make a DMPlexSetCones(), but as you point out, the workflow for DMSetUp() would have to change. Where does the memory come from for your connectivity? Thanks, Matt Sincerely: J.A. Ferrand Embry-Riddle Aeronautical University - Daytona Beach - FL Ph.D. Candidate, Aerospace Engineering M.Sc. Aerospace Engineering B.Sc. Aerospace Engineering B.Sc. Computational Mathematics Phone: (386)-843-1829 Email(s): ferra...@my.erau.edu<mailto:ferra...@my.erau.edu> jesus.ferr...@gmail.com<mailto:jesus.ferr...@gmail.com> -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://urldefense.us/v3/__https://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVQRKJmPA$ <https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVu0P9fBI$ > ________________________________ From: Matthew Knepley <knep...@gmail.com<mailto:knep...@gmail.com>> Sent: Wednesday, May 1, 2024 8:07 PM To: Ferrand, Jesus A. <ferra...@my.erau.edu<mailto:ferra...@my.erau.edu>> Cc: petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov> <petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov>> Subject: [EXTERNAL] Re: [petsc-users] Is there anything like a "DMPlexSetCones()" ? CAUTION: This email originated outside of Embry-Riddle Aeronautical University. Do not click links or open attachments unless you recognize the sender and know the content is safe. On Wed, May 1, 2024 at 3:34 PM Ferrand, Jesus A. <ferra...@my.erau.edu<mailto:ferra...@my.erau.edu>> wrote: This Message Is From an External Sender This message came from outside your organization. Dear PETSc team: For a project that I'm working on, I need to manually build a DMPlex. >From studying the source code of the various APIs in which the plex is built >from some supported file format, I get that the workflow is this: 1. DMPlexSetChart() <-- Input nCells + nVerts 2. DMPlexSetConeSize() <-- Input ConeSize for each point in [0,nCells) 3. DMSetUp() – Allocates memory internally. 4. DMPlexGetCones() --> Gives you the memory onto which to write the cell connectivity. 5. *Write connectivity* 6. DMPlexReorderCell() <-- For each point in [0,nCells) I'm in a situation where the memory given by step (4) is available a-priori. I was hoping to skip steps 2, 3 , and 4 with something like a "DMPlexSetCones()", but such an API does not exist. My current workaround is to implement steps 2 through 4 as always and have double the memory allocated in the interim (my instance + DM's internal instance). I was thinking of looking for the name of the struct member and = it to my memory, but I can't overcome the flag check in DMSetUp() during later calls to DMPlexGetCones() or DMPlexGetTransitiveClosure(). I do not understand the "flag check". What is that? We could make a DMPlexSetCones(), but as you point out, the workflow for DMSetUp() would have to change. Where does the memory come from for your connectivity? Thanks, Matt Sincerely: J.A. Ferrand Embry-Riddle Aeronautical University - Daytona Beach - FL Ph.D. Candidate, Aerospace Engineering M.Sc. Aerospace Engineering B.Sc. Aerospace Engineering B.Sc. Computational Mathematics Phone: (386)-843-1829 Email(s): ferra...@my.erau.edu<mailto:ferra...@my.erau.edu> jesus.ferr...@gmail.com<mailto:jesus.ferr...@gmail.com> -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://urldefense.us/v3/__https://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVQRKJmPA$ <https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVu0P9fBI$ > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://urldefense.us/v3/__https://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVQRKJmPA$ <https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!bg9QrJhAkKOSNFt840OnuOpmX_IlSabDICy99_9tMp9uABL-2lhCm_LG2Fj8rwdySPMiK7rnfMLSIPxs3jDVu0P9fBI$ >