<div dir="ltr"><div dir="ltr"><br></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">Il giorno gio 10 apr 2025 alle ore 11:25 Peder Jørgensgaard Olesen via petsc-users <<a href="mailto:petsc-users@mcs.anl.gov">petsc-users@mcs.anl.gov</a>> ha scritto:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div class="msg-2908047130999226995">




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I would like to output the contents of a Vec to an ASCII file in which the entries are all on one line, as "x[0]  x[1]  x[2]  ...  x[N-1]". This can be done in a slightly roundabout way by putting the values in a 1xN dense Mat, assembling the matrix, and then
 use MatView with a suitable format, but one would think that skipping the matrix step and use a VecView directly would be more efficient (the procedure is to be repeated many times).</div></div></div></blockquote><div><br></div><div>You can use VecGetArrayRead to get the vector data and pass the array to MatCreateDense. Isn't that efficient enough?</div><div><br></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div class="msg-2908047130999226995"><div dir="ltr"><div style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">However, none of the viewer formats seems to support the desired output formatting
 for Vec.</div>
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Is there any way to customize viewer formats for a specific layout - or is there perhaps a more clever way to do the thing I want?</div>
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Also, somewhat relatedly, is there a more detailed specification of available viewer formats? The documentation for PetscViewerFormat (<a href="https://urldefense.us/v3/__https://petsc.org/release/manualpages/Viewer/PetscViewerFormat/*petscviewerformat__;Iw!!G_uCfscf7eWS!fmgo_gSUThwXeUVpPBhwFVgTXRhk3tS8gDcRbkXu6TQu9lj3Emm5wwGKPUktzKcWMN-isoQKklivtNv-eU4$" id="m_-1300807470454454986LPlnk575241" target="_blank">https://petsc.org/release/manualpages/Viewer/PetscViewerFormat/#petscviewerformat</a>)
 briefly describes a number of them, and notes that "A variety of specialized formats also exist", although this isn't elaborated.</div>
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Thanks!</div>
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Best,</div>
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Peder</div>
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<span style="line-height:17px"><a href="https://urldefense.us/v3/__https://www.dtu.dk/english__;!!G_uCfscf7eWS!fmgo_gSUThwXeUVpPBhwFVgTXRhk3tS8gDcRbkXu6TQu9lj3Emm5wwGKPUktzKcWMN-isoQKklivEFUBK2I$" style="color:black;text-decoration:none;margin:0px" target="_blank">www.dtu.dk/english</a></span></div>
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</div></blockquote></div><div><br clear="all"></div><br><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature">Stefano</div></div>