On 6/14/06, <b class="gmail_sendername">Christophe Picard</b> <<a href="mailto:picard2@llnl.gov">picard2@llnl.gov</a>> wrote:<div><span class="gmail_quote"></span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Hello,<br><br>I have been trying to used DMMG and DA in the following way.<br>I have a DA with several degree of freedom, and several of them have the same<br>jacobian but different RHS (what I want to do is solve Ax1=b1(x1,x,2,x3),
<br>Ax2=b2(x1,x2,x3)).<br>So how does DMMGsolve handle that?</blockquote><div><br>
I am not sure I understand completely what you want, but I will start with the<br>
DA. DA objects only encode a data layout. All data resides in Vec and Mat<br>
objects. So, if you have several fields that you want to solve separately, then<br>
create a DA with 1 dof, and use several Vecs. Since the Jacobian is the same,<br>
you will have 1 Mat.<br>
<br>
Matt<br>
</div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Since x1,x2,x3 are DA variables, but I want to solve only x1 and x2 using the<br>
same Jacobian, I figured that I can have some kind of switch in the<br>definition of the RHS function that will make the selection, and calling<br>dmmgSolve several times, but by modifyng the switch trough DMMGSetUser and
<br>DMMGGetUser before each call. But then where the output of the solve<br>operation is stored? The way I understand it now is that it is overwritting<br>x1. Am I right?<br>Is there a way to solve x1 and x2 simultaneously, I mean by only 1 call of
<br>dmmgSolve, and without solving x3?<br><br>I hope I am not too confusing.<br><br>Thank you,<br><br>Christophe<br>---<br><br><br></blockquote></div><br><br clear="all"><br>-- <br>"Failure has a thousand explanations. Success doesn't need one" -- Sir Alec Guiness