<div dir="ltr">Hello everyone,<div><br></div><div>I have some questions about running ex14 with different options -snes_fd -fdcoloring and -snes_mf.</div><div><br></div><div>I run ex14 with -snes_max_it 1 to see how many function evaluations and linear solver iterations take.</div>
<div><br></div><div>In this example, there are 64 unknowns.</div><div><br></div><div>1) -fdcoloring. For -fdcoloring, -snes_view says "total number of function evaluations=2" while the real number of calls of FormFunction (by putting a counter inside the function) is 30. Only 2 function calls reported by snes_view seems to be small. How does snes_view count the number of function evaluations? (For snes_fd, the number of function evaluations is 67 (64+3), which is normal.)</div>
<div><br></div><div>If I use -snes_fd_color, it still says "total number of function evaluations=2" while the counter inside the FormFunction tells 12 now. </div>
<div><br></div><div>2) -snes_mf. For -snes_mf, "the total number of linear solver iterations=1". Given that no preconditioner (pcnone) is used, why does the gmres converges in just one iteration?</div><div><br>
</div><div>Thank you.</div><div><br></div><div>Xiangdong</div></div>