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    <p>Hi Guillaume,</p>
    <p>thanks for the quick reply.</p>
    <p>I realized soon after sending my email that I did not attach a
      MWE. I was waiting for the email to appear on the mailing so that
      I could reply to myself on that one, but it took some time... It's
      attached now.</p>
    <p>I managed to get it done by using fields *and* setting
      Mesh.CharacteristicLengthExtendFromBoundary to 0 -- see result in
      attached PNG.<br>
    </p>
    <p>Regarding your ideas:</p>
    <p>1) I'm really trying to mesh a disk shape.</p>
    <p>2) If there's an easier way to do it, great. I tried the
      characteristic length scale approach as well -- see attached MWE
      -- but that didn't work well. Either the inner part is completely
      meshed with small entities, or the result is very weird.</p>
    <p>3) I did not know about the Line in Surface command. Will try
      that one, too.</p>
    <p>Best,</p>
    <p>Matthias<br>
    </p>
    <br>
    <div class="moz-cite-prefix">On 06/19/2017 05:10 PM, DILASSER
      Guillaume wrote:<br>
    </div>
    <blockquote
cite="mid:BDF3E5E1B74E12499732EC24EF50B5D4AA4591@E-EXDAGE-A0.extra.cea.fr"
      type="cite">
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        <p class="MsoPlainText">Hi Matthias,<o:p></o:p></p>
        <p class="MsoPlainText"><o:p> </o:p></p>
        <p class="MsoPlainText"><span lang="EN-US">It would have been
            nice to see the script file you are working on to better
            identify the error, nevertheless here are a few questions :<o:p></o:p></span></p>
        <p class="MsoPlainText"
          style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l0
          level1 lfo1">
          <!--[if !supportLists]--><span style="font-family:Symbol"
            lang="EN-US"><span style="mso-list:Ignore">·<span
                style="font:7.0pt "Times New Roman"">        
              </span></span></span><!--[endif]--><span lang="EN-US">Are
            you trying to mesh a disk or a donut shape ? In the latter
            case, did you properly define the hole in the surface (see
            Plane Surface
            <a moz-do-not-send="true"
              href="http://gmsh.info/doc/texinfo/gmsh.html#Surfaces">here</a>)?<o:p></o:p></span></p>
        <p class="MsoPlainText"
          style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l0
          level1 lfo1">
          <!--[if !supportLists]--><span style="font-family:Symbol"
            lang="EN-US"><span style="mso-list:Ignore">·<span
                style="font:7.0pt "Times New Roman"">        
              </span></span></span><!--[endif]--><span lang="EN-US">Do
            you really need fields to control your mesh density ? Using
            point characteristic lengths (see Point
            <a moz-do-not-send="true"
              href="http://gmsh.info/doc/texinfo/gmsh.html#Points">here</a>)
            may be enough and far easier to implement.<o:p></o:p></span></p>
        <p class="MsoPlainText"
          style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l0
          level1 lfo1">
          <!--[if !supportLists]--><span style="font-family:Symbol"
            lang="EN-US"><span style="mso-list:Ignore">·<span
                style="font:7.0pt "Times New Roman"">        
              </span></span></span><!--[endif]--><span lang="EN-US">If
            you want to mesh a disk, you will want to embed the inner
            circle in the disk defined by the outer one using the Line
            in Surface command (see
            <a moz-do-not-send="true"
href="http://gmsh.info/doc/texinfo/gmsh.html#Miscellaneous-mesh-commands">here</a>).<o:p></o:p></span></p>
        <p class="MsoPlainText"><span lang="EN-US">Did it help ? Let me
            know if you still have questions,<o:p></o:p></span></p>
        <p class="MsoNormal"><o:p> </o:p></p>
        <p class="MsoNormal"><span
style="font-family:"Tahoma",sans-serif;color:#000099;mso-fareast-language:FR">Guillaume
            DILASSER</span><span
style="font-size:10.0pt;font-family:"Tahoma",sans-serif;color:#000099;mso-fareast-language:FR"><o:p></o:p></span></p>
        <p class="MsoNormal"><span
style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#000099;mso-fareast-language:FR">Doctorant
            SACM / LEAS<o:p></o:p></span></p>
        <p class="MsoNormal"><span
style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#000099;mso-fareast-language:FR">CEA
            - Centre de Saclay - Bât.123 - PC 319c</span><span
            style="color:#000099;mso-fareast-language:FR"><o:p></o:p></span></p>
        <p class="MsoNormal"><span
style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#000099;mso-fareast-language:FR">91191
            Gif sur Yvette Cedex - France -</span><span
            style="color:#000099;mso-fareast-language:FR"><o:p></o:p></span></p>
        <p class="MsoNormal"><span
style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#000099;mso-fareast-language:FR"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span
style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#000099;mso-fareast-language:FR"><a
              moz-do-not-send="true"
              href="mailto:guillaume.dilasser@cea.fr"><span
                style="color:blue">guillaume.dilasser@cea.fr</span></a><o:p></o:p></span></p>
        <p class="MsoPlainText"><span lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoPlainText"><span style="mso-fareast-language:FR">-----Message
            d'origine-----<br>
            De : gmsh [<a class="moz-txt-link-freetext" href="mailto:gmsh-bounces@ace20.montefiore.ulg.ac.be">mailto:gmsh-bounces@ace20.montefiore.ulg.ac.be</a>]
            De la part de Matthias Sitte<br>
            Envoyé : lundi 19 juin 2017 13:18<br>
            À : <a class="moz-txt-link-abbreviated" href="mailto:gmsh@onelab.info">gmsh@onelab.info</a><br>
            Objet : [Gmsh] refining the mesh of a circle with Attractor
            Fields</span></p>
        <p class="MsoPlainText"><o:p> </o:p></p>
        <p class="MsoPlainText">Hi all,<o:p></o:p></p>
        <p class="MsoPlainText"><o:p> </o:p></p>
        <p class="MsoPlainText">I'm trying to set up the following
          problem:<o:p></o:p></p>
        <p class="MsoPlainText"><o:p> </o:p></p>
        <p class="MsoPlainText">1) Create a circular geometry with
          radius R_outer using 4 Circles and a Line Loop which defines
          the outer boundary of the mesh.<o:p></o:p></p>
        <p class="MsoPlainText"><o:p> </o:p></p>
        <p class="MsoPlainText">2) Create another closed circle (again
          made out of 4 Circles) with radius R_inner inside the circular
          mesh.<o:p></o:p></p>
        <p class="MsoPlainText"><o:p> </o:p></p>
        <p class="MsoPlainText">3) Goal is to reduce lchar and create a
          finer mesh close the inner circle, but keep the coarser mesh
          everywhere else.<o:p></o:p></p>
        <p class="MsoPlainText"><o:p> </o:p></p>
        <p class="MsoPlainText">So far I've started from the example
          t10.geo and mostly got what I wanted. But I observed that if I
          close the inner circle, all of the mesh within the circle is
          meshed with reduced lchar, not the lchar I would've expected.
          When I open the circle by leaving out segment(s), the result
          looks better w.r.t. mesh size, but it's of course not what I
          want. Am I missing something here?<o:p></o:p></p>
        <p class="MsoPlainText"><o:p> </o:p></p>
        <p class="MsoPlainText">Best,<o:p></o:p></p>
        <p class="MsoPlainText"><o:p> </o:p></p>
        <p class="MsoPlainText">Matthias<o:p></o:p></p>
        <p class="MsoPlainText"><o:p> </o:p></p>
        <p class="MsoPlainText"><o:p> </o:p></p>
        <p class="MsoPlainText">_______________________________________________<o:p></o:p></p>
        <p class="MsoPlainText">gmsh mailing list<o:p></o:p></p>
        <p class="MsoPlainText"><a moz-do-not-send="true"
            href="mailto:gmsh@onelab.info"><span
              style="color:windowtext;text-decoration:none">gmsh@onelab.info</span></a><o:p></o:p></p>
        <p class="MsoPlainText"><a moz-do-not-send="true"
            href="http://onelab.info/mailman/listinfo/gmsh"><span
              style="color:windowtext;text-decoration:none">http://onelab.info/mailman/listinfo/gmsh</span></a><o:p></o:p></p>
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