[petsc-users] DAGlobalToLocalBegin()

[(Rebecca) Xuefei YUAN]

Hi,all,

I have an error from

ierr = DAGlobalToLocalBegin(dafield,X,INSERT_VALUES,localFIELD);  
CHKERRQ(ierr);

where

ierr = DMMGSetSNES(dmmg, FormFunction,0);CHKERRQ(ierr); is used for  
set up the SNES.

So I check up the vector size of X, F, localFIELD where
	ierr = DAGetLocalVector(dafield,&localFIELD);CHKERRQ(ierr);
	PetscInt	nlocalFIELD,nX,nF;
	ierr = VecGetSize(localFIELD,&nlocalFIELD);CHKERRQ(ierr);
	ierr = VecGetSize(X,&nX);CHKERRQ(ierr);
	ierr = VecGetSize(F,&nF);CHKERRQ(ierr);
	ierr = DAGlobalToLocalBegin(dafield,X,INSERT_VALUES,localFIELD);  
CHKERRQ(ierr);
	ierr = DAGlobalToLocalEnd(dafield,X,INSERT_VALUES,localFIELD);CHKERRQ(ierr);
  	ierr = DAVecGetArray(dafield,localFIELD,&localfield);CHKERRQ(ierr);


(gdb) disp nX
1: nX = 120
(gdb) disp nF
2: nF = 120
(gdb) disp nlocalFIELD
3: nlocalFIELD = 100
(gdb) where
#0  FormFunction (snes=0x8a47840, X=0x8a39c20, F=0x8a37570, dummg=0x8a2b810)
     at twgcqt2unffnictv.c:8382
#1  0x080fb28f in SNESComputeFunction (snes=0x8a47840, x=0x8a39c20,
     y=0x8a37570) at snes.c:1093
#2  0x08123d1b in SNESSolve_LS (snes=0x8a47840) at ls.c:159
#3  0x08103fac in SNESSolve (snes=0x8a47840, b=0x0, x=0x8a39c20) at  
snes.c:2242
#4  0x0811db31 in DMMGSolveSNES (dmmg=0x8a2b6b0, level=0) at damgsnes.c:510
#5  0x08117029 in DMMGSolve (dmmg=0x8a2b6b0) at damg.c:313
#6  0x08052ecc in Solve (dmmg=0x8a2b6b0) at twgcqt2unffnictv.c:679
#7  0x0804def5 in main (argc=Cannot access memory at address 0x0
) at twgcqt2unffnictv.c:303

3: nlocalFIELD = 100
2: nF = 120
1: nX = 100
(gdb) where
#0  FormFunction (snes=0x8a47840, X=0x8b39cc0, F=0x8adb2f0, dummg=0x8a2b810)
     at twgcqt2unffnictv.c:8382
#1  0x0860c63d in MatFDColoringApply_AIJ (J=0x8a6bbb0, coloring=0x8aa7b40,
     x1=0x8b12a60, flag=0xbfbf4404, sctx=0x8a47840) at fdmatrix.c:680
#2  0x0860abaf in MatFDColoringApply (J=0x8a6bbb0, coloring=0x8aa7b40,
     x1=0x8b12a60, flag=0xbfbf4404, sctx=0x8a47840) at fdmatrix.c:521
#3  0x08122e45 in SNESDefaultComputeJacobianColor (snes=0x8a47840,
     x1=0x8b12a60, J=0x8a47910, B=0x8a47914, flag=0xbfbf4404, ctx=0x8aa7b40)
     at snesj2.c:49
#4  0x0811c7cf in DMMGComputeJacobianWithFD (snes=0x8a47840, x1=0x8a39c20,
     J=0x8a47910, B=0x8a47914, flag=0xbfbf4404, ctx=0x8a2b810) at  
damgsnes.c:365
#5  0x0811a883 in DMMGComputeJacobian_Multigrid (snes=0x8a47840, X=0x8a39c20,
     J=0x8a47910, B=0x8a47914, flag=0xbfbf4404, ptr=0x8a2b6b0) at damgsnes.c:60
#6  0x080fc610 in SNESComputeJacobian (snes=0x8a47840, X=0x8a39c20,
     A=0x8a47910, B=0x8a47914, flg=0xbfbf4404) at snes.c:1188
#7  0x08124471 in SNESSolve_LS (snes=0x8a47840) at ls.c:189
#8  0x08103fac in SNESSolve (snes=0x8a47840, b=0x0, x=0x8a39c20) at  
snes.c:2242
#9  0x0811db31 in DMMGSolveSNES (dmmg=0x8a2b6b0, level=0) at damgsnes.c:510
#10 0x08117029 in DMMGSolve (dmmg=0x8a2b6b0) at damg.c:313
#11 0x08052ecc in Solve (dmmg=0x8a2b6b0) at twgcqt2unffnictv.c:679
#12 0x0804def5 in main (argc=Cannot access memory at address 0x1
) at twgcqt2unffnictv.c:303

Why nX changes from 120 to 100? Is X a global vector or a local vector?

Thanks very much!



-- 
(Rebecca) Xuefei YUAN
Department of Applied Physics and Applied Mathematics
Columbia University
Tel:917-399-8032
www.columbia.edu/~xy2102