<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Another way is explained here<div class=""><br class=""></div><div class=""><a href="https://lists.mcs.anl.gov/pipermail/petsc-users/2019-May/038519.html" class="">https://lists.mcs.anl.gov/pipermail/petsc-users/2019-May/038519.html</a></div><div class=""><br class=""></div><div class="">Best</div><div class="">praveen<br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On 03-Dec-2020, at 6:21 PM, Praveen C <<a href="mailto:cpraveen@gmail.com" class="">cpraveen@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta charset="UTF-8" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; 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; float: none; display: inline !important;" class="">We have used this in our code, though I did not implement it, so I dont know the details. </span><div class="" style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; 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;"><br class=""></div><div class="" style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; 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;">Here is sample code<div class=""><br class=""></div><div class=""><div class="" style="margin: 0px; font-stretch: normal; font-size: 12px; line-height: normal; font-family: Menlo; background-color: rgb(255, 255, 255);"><br class=""></div><div class="" style="margin: 0px; font-stretch: normal; font-size: 12px; line-height: normal; font-family: Menlo; background-color: rgb(255, 255, 255);"><div class="" style="margin: 0px; font-stretch: normal; line-height: normal; color: rgb(64, 11, 217);"><span class="" style="font-variant-ligatures: no-common-ligatures;"> </span><span class="" style="font-variant-ligatures: no-common-ligatures;">// get gmsh boundary tag</span></div><div class="" style="margin: 0px; font-stretch: normal; line-height: normal;"><span class="" style="font-variant-ligatures: no-common-ligatures;"> PetscInt bdry_tag;</span></div><div class="" style="margin: 0px; font-stretch: normal; line-height: normal;"><span class="" style="font-variant-ligatures: no-common-ligatures;"> ierr = DMGetLabelValue(dm,<span class="Apple-converted-space"> </span></span><span class="" style="font-variant-ligatures: no-common-ligatures; color: rgb(180, 36, 25);">"Face Sets"</span><span class="" style="font-variant-ligatures: no-common-ligatures;">, face_no, &bdry_tag); CHKERRQ(ierr);</span></div></div><div class=""><br class=""></div><div class="">Best</div><div class="">praveen</div></div></div></div></blockquote></div><br class=""></div></body></html>