 Usage:  lx = grxline (x, v {, col})  
 
 Input:

  x                      scalar 
                         
  v                      n x 1 vector 
                         
  col                    color 
                         
 Output:

  lx                     composed graphical object 
                         
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(C) MD*TECH Method and Data Technologies, 17.8.2000
