<div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><font face="tahoma, sans-serif">Dear Petsc developer:            </font></div><div dir="ltr"><font face="tahoma, sans-serif">Hi, </font></div><div dir="ltr"><p class="gmail-15" align="justify" style="text-align:justify"><font face="arial, helvetica, sans-serif"><span style="letter-spacing:0pt;background-image:initial;background-position:initial;background-size:initial;background-repeat:initial;background-origin:initial;background-clip:initial">Thank you very much for your previous reply, recently I encountered some problems in the implementation of the program.</span><span style="letter-spacing:0pt;background-image:initial;background-position:initial;background-size:initial;background-repeat:initial;background-origin:initial;background-clip:initial"></span></font></p><p class="gmail-15" align="justify" style="text-align:justify"><font face="arial, helvetica, sans-serif"><span style="letter-spacing:0pt;background-image:initial;background-position:initial;background-size:initial;background-repeat:initial;background-origin:initial;background-clip:initial">1. </span><span style="letter-spacing:0pt;background-image:initial;background-position:initial;background-size:initial;background-repeat:initial;background-origin:initial;background-clip:initial">Previously I used DMDA to create distributed variables (Variables are different in each grids). Now I want to add a single variable (independent of the grid). How do I add it? How do I write programs with distributed variables and single variables exist at</span> the same time? </font></p><p class="gmail-15" align="justify" style="text-align:justify"><font face="arial, helvetica, sans-serif">I've created three "Field" variables before, and I'd like to add a single variable. How should I describe it in the program? The codes are as below.<br></font></p></div></div></div><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px"><div><div><div><p class="gmail-15"><font face="arial, helvetica, sans-serif"><span style="color:rgb(34,34,34);letter-spacing:0pt;text-transform:none;font-style:normal;background:rgb(255,255,255)">ierr=DMDACreate2d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_STAR,10,10,PETSC_DECIDE,PETSC_DECIDE,3,1,0,0,&da);CHKERRQ(ierr);</span></font></p></div></div></div><div><div><div><p class="gmail-15"><font face="arial, helvetica, sans-serif"><span style="color:rgb(34,34,34);letter-spacing:0pt;text-transform:none;font-style:normal;background:rgb(255,255,255)">  ierr = DMSetFromOptions(da);CHKERRQ(ierr);</span></font></p></div></div></div><div><div><div><p class="gmail-15"><font face="arial, helvetica, sans-serif"><span style="color:rgb(34,34,34);letter-spacing:0pt;text-transform:none;font-style:normal;background:rgb(255,255,255)">  ierr = DMSetUp(da);CHKERRQ(ierr);</span></font></p></div></div></div><div><div><div><p class="gmail-15"><font face="arial, helvetica, sans-serif"><span style="color:rgb(34,34,34);letter-spacing:0pt;text-transform:none;font-style:normal;background:rgb(255,255,255)">  ierr = SNESSetDM(snes,(DM)da);CHKERRQ(ierr);</span></font></p></div></div></div><div><div><div><p class="gmail-15"><font face="arial, helvetica, sans-serif"><span style="color:rgb(34,34,34);letter-spacing:0pt;text-transform:none;font-style:normal;background:rgb(255,255,255)">  ierr = DMDASetFieldName(da,0,"Pressure");CHKERRQ(ierr);</span></font></p></div></div></div><div><div><div><p class="gmail-15"><font face="arial, helvetica, sans-serif"><span style="color:rgb(34,34,34);letter-spacing:0pt;text-transform:none;font-style:normal;background:rgb(255,255,255)">  ierr = DMDASetFieldName(da,1,"Y-Velocity");CHKERRQ(ierr);</span></font></p></div></div></div><div><div><div><p class="gmail-15"><span style="letter-spacing:0pt;background-image:initial;background-position:initial;background-size:initial;background-repeat:initial;background-origin:initial;background-clip:initial"><font face="arial, helvetica, sans-serif">  ierr = DMDASetFieldName(da,2,"Fluid_temperature");CHKERRQ(ierr);</font></span></p><p class="gmail-15"><span style="font-family:arial,helvetica,sans-serif">  ierr = DMCreateGlobalVector(da,&x);CHKERRQ(ierr);</span></p></div></div></div></blockquote><div dir="ltr"><div dir="ltr"><div dir="ltr"><p class="gmail-15" align="justify" style="text-align:justify"></p><p class="gmail-15"><span style="font-family:宋体;letter-spacing:0pt;font-size:12pt;background-image:initial;background-position:initial;background-size:initial;background-repeat:initial;background-origin:initial;background-clip:initial"></span></p><p class="gmail-15" align="justify" style="text-align:justify"><font face="arial, helvetica, sans-serif"><span style="letter-spacing:0pt;background-image:initial;background-position:initial;background-size:initial;background-repeat:initial;background-origin:initial;background-clip:initial">2. </span><span style="letter-spacing:0pt;background-image:initial;background-position:initial;background-size:initial;background-repeat:initial;background-origin:initial;background-clip:initial">At present, I am solving nonlinear equations. Now I need to do one-step nonlinear calculation first, and then treat the results as coefficients for the subsequent nonlinear calculation. Now I used to use SNESSolve() directly to solve the problem. How can we calculate step by step and process the result before entering the next nonlinear step? </span></font><span style="font-family:宋体;letter-spacing:0pt;font-size:12pt;background-image:initial;background-position:initial;background-size:initial;background-repeat:initial;background-origin:initial;background-clip:initial"></span></p><div><font color="#333333"><font face="tahoma, sans-serif">Since I'm a beginner in PETSc, I would be grateful if there were any examples.<br></font></font></div><div><font color="#333333"><font face="tahoma, sans-serif">I'm looking forward to your reply~</font></font></div><div><font color="#333333"><font face="tahoma, sans-serif"><br></font></font></div><div><font color="#333333"><font face="tahoma, sans-serif">Thanks,</font></font></div><div><font color="#333333"><font face="tahoma, sans-serif">Yingjie</font></font></div><p class="gmail-15" align="justify" style="text-align:justify"><font face="arial, helvetica, sans-serif"><span style="letter-spacing:0pt;background-image:initial;background-position:initial;background-size:initial;background-repeat:initial;background-origin:initial;background-clip:initial"><br></span></font></p></div></div></div></div></div></div>