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Subject: Re: APDL - selecting nodes
Author: Don Shaffer
Date: 2002-09-30 14:01:00

I have not looked in the documentation on this
but you may be able to sequence thru your nodes
using one of the *get commands for lines (perhaps.)
Typically the mesh sequence for a line with only the
two endpoints is to place a node at each end then
fill in between with the number based upon
a.) user specified number of edge divisions
b.) specified edge length
c.) user specified global element size
d.) default element edge length

I am uncertain if that is the same sequence that is
used for splines. You may want to do testing to see
if that is the case.

Another approach is to *get the number of nodes on the
line, or alternatively use the line inquiry functions
and then select only those nodes attached to the line
from the full model, next *get the node number of the
node on one end of your model. Next use the nodenearest
functions to get the next closest node. Unselect the
first node from your current group of selected nodes.
now get the node nearest the second node in the group.
continue through this until you reach the end of the
number of nodes associated with this line. Get the next
line and attached nodes, continue the identification
process starting with the last node identified in the
first line. After identification create the groups
of the node numbers you have saved in an array.

Regards
Don Shaffer
Siemens Westinghouse Power Corp.
Orlando, Florida

-----Original Message-----
Sent: September 30, 2002 12:36 PM
To: xansys@yahoogroups.com

Hi, Rene!

The line created by BSPLIN is sinuous and has more than 300ø from
start to end (almost close). Hence I guess this approach would not
run because the lack of a logical orderind rule.

Thanks, any way.

Glailson Mattos
Metallurgist Engineer
USIMINAS - BRAZIL

--- In xansys@y..., "Fiege, Rene" wrote:
> Glailson

> you can use vector/matrix commands.
> 1) create a matrix with the node numbers and the coordinates
> matrix(NodeNumber,x,y,z) -> including all coordinates you have
to filter
> 2) sort matrix using the direction you are interested in (*moper)
> 3) compress to the nodes of interest
> 4) use the *do loop on the vector, which is faster than the
selection

> I suppose you select the nodes by a location in a specific
coordinate
> system, which is faster, because you do not need a *do loop at all.
You can
> directly create a masking vector for the matrix comparing the
coordinate
> data to a specific location information using *voper (in fact in
this case
> the matrix could be a vector holding the coordinates only).

> Hope this helps,

> Ren‚ Fiege
> Meyer Werft
> Germany

> -----Original Message-----
> From: glailson_mattos [mailto:gmaraujo@u...]
> Sent: Monday, September 30, 2002 2:27 PM
> To: xansys@y...
> Subject: [xansys] APDL - selecting nodes

> Hi, XANSYSers!

> My model has a sinuous line build by the BSPLIN command. Attached
to
> that line there are a lot of nodes from the mesh operation.
> I need separate those nodes in two groups from each ten consecutive
> nodes on the line (the nodes' numbering is randomic and there isn't
> any geometric rule). I mean create two components like the
following
> scheme

> 111111111100000000001111111111000000000011111111110000000000 .......

> I am able to count the select nodes and separate the nodes's number
> in two arrays using a *DO loop and after that issue a NSEL,s,....
and
> NSEL,a,... for each array index, but this solution is slow and not
> very smart.

> Does anyone know a smart and fast method to get it?
> Any help is welcome.

> Glailson Mattos
> Metallurgist Engineer
> USIMINAS - BRAZIL
Posts possibly associated with message #42308AuthorDateScore
42292APDL - selecting nodesGlailson Mattos2002/09/30 
42297Re: APDL - selecting nodesRene Fiege2002/09/30 
42304Re: APDL - selecting nodesGlailson Mattos2002/09/30 
42308Re: APDL - selecting nodesDon Shaffer2002/09/30 
42310Re: APDL - selecting nodesGlailson Mattos2002/09/30 
42311Re: APDL - selecting nodesOtto, Mike J MikeJOtto@2002/09/30 
65891[APDL] selecting nodesBarry O'Donnell2004/01/22 
65892Re: [APDL] selecting nodesRick Fischer2004/01/22 
65893Re: [APDL] selecting nodesGordon May2004/01/22 
65905Re: [APDL] selecting nodesBarry O'Donnell2004/01/22 
66014Re: [APDL] selecting nodesBarry O'Donnell2004/01/27 
66020Re: [APDL] selecting nodesAdam Shinbrot2004/01/27