MantisBT - VTK
View Issue Details

ID	Project	Category	View Status	Date Submitted	Last Update
0002903	VTK	(No Category)	public	2006-02-22 11:24	2013-04-05 19:57

Reporter	Randall Hand
Assigned To	Zhanping Liu
Priority	urgent	Severity	minor	Reproducibility	always
Status	closed	Resolution	open
Platform		OS		OS Version
Product Version
Target Version		Fixed in Version
Project
Type

Summary	0002903: vtkArrayCalculator does not support Cross Products
Description	the existing vtkArrayCalculator (in both VTK & ParaView) does not support computation of Cross Products. As this is important in my work, I modified the Common/vtkFunctionParser.cxx/h to support a "cross" function that takes 2 vectors as input.
Steps To Reproduce
Additional Information
Tags	No tags attached.
Relationships
Attached Files	vtkFunctionParser.cxx (58,630) 1969-12-31 19:00 https://www.vtk.org/Bug/file/5467/vtkFunctionParser.cxx vtkFunctionParser.h (8,616) 1969-12-31 19:00 https://www.vtk.org/Bug/file/5468/vtkFunctionParser.h

Issue History
Date Modified	Username	Field	Change
2008-09-25 15:29	Berk Geveci	Assigned To	Mathieu Malaterre => Zhanping Liu
2008-10-09 18:40	Zhanping Liu	Note Added: 0013828
2008-10-09 18:42	Zhanping Liu	Status	tabled => @80@
2008-10-09 18:42	Zhanping Liu	Description Updated
2011-06-16 13:11	Zack Galbreath	Category	=> (No Category)
2013-04-05 19:57	Berk Geveci	Status	customer review => closed

Notes

randall.hand once suggested the addition of the support for the vector cross product operator. It was added some time later. Then some new operators such as boolean ones were added and during this process unfortunately the vector cross product operator was carelessly disabled due to the incorrect check on the number of the input parameters.

The correct format of a vector cross product operation is:

    ====================================
    vector_C = cross(vector_A, vector_B)
    ====================================

    INSTEAD OF

    ====================================
    cross(vector_A, vector_B, vector_C)
    ====================================

    In other words, there should be TWO parameters and ONE comma.

    However, the bug in vtkFunctionParser:: CheckSyntax() occurred within the following segment (between line 1444 and line 1453):

    ============================================================
    if ((functionNumber == VTK_PARSER_MIN) ||
        (functionNumber == VTK_PARSER_MAX))
      {
      expectCommaOnParenthesisCount[parenthesisCount+1] = 1;
      }
    if ((functionNumber == VTK_PARSER_IF) ||
        (functionNumber == VTK_PARSER_CROSS))
      {
      expectTwoCommasOnParenthesisCount[parenthesisCount+1] = 1;
      }
    ============================================================

    Now this segment has been replaced with

    ============================================================
    if ((functionNumber == VTK_PARSER_MIN) ||
        (functionNumber == VTK_PARSER_MAX) ||
        (functionNumber == VTK_PARSER_CROSS))
      {
      expectCommaOnParenthesisCount[parenthesisCount+1] = 1;
      }
    if (functionNumber == VTK_PARSER_IF)
      {
      expectTwoCommasOnParenthesisCount[parenthesisCount+1] = 1;
      }
    ============================================================

    Now the code performs correct check on the input format in terms of vector cross product and the suggested functionality is supported.

      Thanks for suggesting the enhancement.

      new revision: 1.43; previous revision: 1.42