<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: Times New Roman; font-size: 12pt; color: #000000'><P>Aleks,</P>
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<P>Do I need to include anything in the header, or common block? I added the condition statement, but the simulation quits on the first time step when it calls userchk.</P>
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<P>- Michael</P>
<P><BR>----- Original Message -----<BR>From: nek5000-users@lists.mcs.anl.gov<BR>To: nek5000-users@lists.mcs.anl.gov<BR>Sent: Thursday, July 1, 2010 8:04:41 PM GMT -06:00 US/Canada Central<BR>Subject: Re: [Nek5000-users] Compute the derivatives<BR><BR>Hi Michael,<BR><BR><BR>iostep dump works only for the dump of quantities specified as T in your .rea like<BR><BR> ***** OUTPUT FIELD SPECIFICATION *****<BR> 8 SPECIFICATIONS FOLLOW<BR> T COORDINATES<BR> T VELOCITY<BR> T PRESSURE<BR> T TEMPERATURE<BR> F TEMPERATURE GRADIENT<BR> 2 PASSIVE SCALARS<BR> F<BR> F<BR><BR><BR>Since userchk is called every timestep so you'll need something like<BR><BR><BR>if (mod(istep,iostep).eq.0) then<BR>...<BR><BR>Best,<BR>Aleks<BR><BR><BR><BR>----- Original Message -----<BR>From: nek5000-users@lists.mcs.anl.gov<BR>To: nek5000-users@lists.mcs.anl.gov<BR>Sent: Thursday, July 1, 2010 7:57:07 PM GMT -06:00 US/Canada Central<BR>Subject: Re: [Nek5000-users] Compute the derivatives<BR><BR><BR><BR><BR><BR>Hi Paul and Aleks, <BR><BR><BR><BR>I have a question regarding this. I have implemented this and it is working nicely, however it is dumping <BR><BR>out a .f file every step, rather than every iotime step I have specified in the rea. <BR><BR><BR><BR>Do you know how to fix this? <BR><BR><BR><BR>- Michael <BR><BR><BR>----- Original Message ----- <BR>From: nek5000-users@lists.mcs.anl.gov <BR>To: nek5000-users@lists.mcs.anl.gov <BR>Sent: Wednesday, June 2, 2010 10:57:41 AM GMT -06:00 US/Canada Central <BR>Subject: Re: [Nek5000-users] Compute the derivatives <BR><BR>Hi JC, <BR><BR>To dump the computed derivatives into separate field files you can use in <BR>userchk <BR><BR>ifxyo = .true. ! for cooordinates <BR>ifpo = .false. ! turn off pressure output <BR>ifto = .false. ! turn off pressure output <BR>call outpost(vxx,vxy,vxz,pr,t,'dvx') <BR>call outpost(vyx,vyy,vyz,pr,t,'dvy') <BR>... <BR><BR>Best, <BR>Aleks <BR><BR><BR><BR>On Wed, 2 Jun 2010, nek5000-users@lists.mcs.anl.gov wrote: <BR><BR>> <BR>> dudxyz is somewhat dated and slow... <BR>> <BR>> I recommend somthing like: <BR>> <BR>> parameter (lt=lx1*ly1*lz1*lelv) <BR>> common /mygrad/ vxx(lt),vxy(lt),vxz(lt) <BR>> $ , vyx(lt),vyy(lt),vyz(lt) <BR>> $ , vzx(lt),vzy(lt),vzz(lt) <BR>> <BR>> call gradm1(vxx,vxy,vxz,vx) <BR>> call gradm1(vyx,vyy,vyz,vy) <BR>> call gradm1(vzx,vzy,vzz,vz) <BR>> <BR>> Note that putting these arrays into a common block, as <BR>> shown, is a good idea for several reasons, one of which <BR>> is that it guarantees that the data will be byte-aligned with the cache line. <BR>> On some machines (e.g., BG/P) this <BR>> is crucial for proper functionality - for this reason we <BR>> don't mix variable types in a given common block. <BR>> <BR>> If you subsequently wish to access elements of vxx etc. <BR>> on an element-by-element basis you can of course do something <BR>> like <BR>> <BR>> parameter (lt=lx1*ly1*lz1) <BR>> common /mygrad/ vxx(lt,lelt),vxy(lt,lelt),vxz(lt,lelt) <BR>> : <BR>> : <BR>> <BR>> Paul <BR>> <BR>> On Wed, 2 Jun 2010, nek5000-users@lists.mcs.anl.gov wrote: <BR>> <BR>>> Hi Nek's, <BR>>> <BR>>> I have a home-made global stability code, but in order to use it I first <BR>>> need to compute the derivatives of my base flow: dUdX, dUdY, dVdX, dVdY. <BR>>> How could one compute these derivatives using Nek 5k and drop them along <BR>>> with X Y U V in the blah.f**** file (or perhaps another .f**** file) ? I <BR>>> assume I have to make use of the subroutine *dudxyz <BR>>> (du,u,rm1,sm1,tm1,jm1,imsh,isd)*, but I'm not sure what to put as inputs. <BR>>> <BR>>> Regards, <BR>>> JC <BR>>> <BR>> _______________________________________________ <BR>> Nek5000-users mailing list <BR>> Nek5000-users@lists.mcs.anl.gov <BR>> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users <BR>> <BR>_______________________________________________ <BR>Nek5000-users mailing list <BR>Nek5000-users@lists.mcs.anl.gov <BR>https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users <BR><BR>_______________________________________________<BR>Nek5000-users mailing list<BR>Nek5000-users@lists.mcs.anl.gov<BR>https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users<BR>_______________________________________________<BR>Nek5000-users mailing list<BR>Nek5000-users@lists.mcs.anl.gov<BR>https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users<BR></P></div></body></html>