Example 211: 2D line element fitted to rectangular cartesian data

Fits a single linear element to 8 data points using iterative linear finite element fitting. The data points are recalculated after each fit to maintain orthogonal projections.

Shown below are the initial and the final fitted mesh. The dark blue pluses represent the data points, the dashed black lines the orthogonal projections and the cyan circles the xi positions on the mesh.

The comfile run by this example is as follows:

# Example_211 2D line element fitted to rectangular cartesian data


fem de node;r;test;example        #2 nodes
fem de base;r;test;example        #linear 1D basis
fem de elem;r;test;example        #1 element
fem de fiel;r;test;example        #create field positions for fitted coords
fem de elem;r;test;example field  #basis for field is linear
fem de data;r;test;example        #8 data points
fem li data                       #data points only
fem de wind
fem dr line
fem dr node
fem dr data
fem de xi;c close                 #find Xi coords by projecting onto closest element
fem li data                       #note elements & Xi locations now defined
fem dr data trace                 #show Xi positions
fem dr data projection            #draw projections
fem up field from geom            #put initial geom into field positions

fem de fit;r;test;example geom    #all Q's defaulted so both geom vars in one fitting problem
fem li fit                        #note one fitting problem with both x & y included

Additional testing commands:

#
#----- 1st fit -----
#
fem fit 
fem up node fit        #puts fitted nodes in field position into coord position
fem dr node            #show new node coords
fem dr line
fem dr data trace      
fem dr data projection #then try zooming in. 
#                      !Note that the projections are no longer orthogonal

#
#----- 2nd fit -----
#
fem de xi;c close old  #recalculate Xi positions but use old ones as starting point
fem dr data trace      
fem dr data projection #the projections are again orthogonal

fem fit 

fem up node fit        
fem dr node            
fem dr line
fem dr data trace      
fem dr data projection #then try zooming in. 
#                      !Note that the projections are closer to orthogonal

fem li data err

Files used by this example are:

Name             Modified     Size

example_211.com  25-Jul-2001  1.0k
test.ipbase      25-Jul-2001  893 
test.ipdata      25-Jul-2001  899 
test.ipelem      25-Jul-2001  332 
test.ipelfd      25-Jul-2001  278 
test.ipfiel      25-Jul-2001  680 
test.ipfit       13-Apr-2007  1.7k
test.ipnode      25-Jul-2001  603 
test_output.com  25-Jul-2001  748 

Download the entire example:

Name                      Modified     Size

examples_2_21_211.tar.gz  27-Aug-2010  7.5k

Testing status by version:

Testing status by file:

• cmiss_test.log
  

  i686-linux
  Success	cm:	cmiss_test.log.retain.
  Success	cm-debug:	cmiss_test.log.retain.
  mips-irix
  Success	cm:	cmiss_test.log.retain.
  Success	cm-debug:	cmiss_test.log.retain.
  Success	cm-debug-clear-malloc:	cmiss_test.log.retain.
  Success	cm-debug-clear-malloc7:	cmiss_test.log.retain.
  Success	cm64:	cmiss_test.log.retain.
  Success	cm64-debug:	cmiss_test.log.retain.
  Success	cm64-debug-clear-malloc:	cmiss_test.log.retain.
  rs6000-aix
  Success	cm:	cmiss_test.log.retain.
  Success	cm-debug:	cmiss_test.log.retain.
  Success	cm64:	cmiss_test.log.retain.
  Success	cm64-debug:	cmiss_test.log.retain.
  x86_64-linux
  Success	cm:	cmiss_test.log.retain.
  Success	cm-debug:	cmiss_test.log.retain.

  
  
• cmiss_test.out
  

  i686-linux
  Success	cm:	ndiff test: no significant differences with generic answer.
  Success	cm-debug:	ndiff test: no significant differences with generic answer.
  mips-irix
  Success	cm:	ndiff test: no significant differences with generic answer.
  Success	cm-debug:	ndiff test: no significant differences with generic answer.
  Success	cm-debug-clear-malloc:	ndiff test: no significant differences with generic answer.
  Success	cm-debug-clear-malloc7:	ndiff test: no significant differences with generic answer.
  Success	cm64:	ndiff test: no significant differences with generic answer.
  Success	cm64-debug:	ndiff test: no significant differences with generic answer.
  Success	cm64-debug-clear-malloc:	ndiff test: no significant differences with generic answer.
  rs6000-aix
  Success	cm:	ndiff test: no significant differences with generic answer.
  Success	cm-debug:	ndiff test: no significant differences with generic answer.
  Success	cm64:	ndiff test: no significant differences with generic answer.
  Success	cm64-debug:	ndiff test: no significant differences with generic answer.
  x86_64-linux
  Success	cm:	ndiff test: no significant differences with generic answer.
  Success	cm-debug:	ndiff test: no significant differences with generic answer.

  
  

Html last generated: Sun Mar 6 05:50:08 2016

Input last modified: Thu Aug 26 13:00:07 2010