User:Tohline/IVAJ/Level1 - Revision history

Tohline: User:Tohline/CPM/Level1 moved to User:Tohline/IVAJ/Level1: Use new name: IVAJ

2010-03-03T17:16:06Z

User:Tohline/CPM/Level1 moved to User:Tohline/IVAJ/Level1: Use new name: IVAJ

← Older revision

Revision as of 17:16, 3 March 2010

Tohline: /* Summary */ Added link

2010-02-09T00:32:18Z

Summary: Added link

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	==<font color="#0000DD">Summary</font>==		==<font color="#0000DD">Summary</font>==

	We've illustrated how, at one particular instant during a CFD simulation, we can determine the orbital period of our simulated binary star system. With this customized visualization tool in hand, we're in a position to determine how the orbital period and other characteristic frequencies vary with time throughout each simulation. More significantly, we now appreciate how we can modify otherwise standard VisTrails workflows to perform any of a variety of analysis tasks that are customized to our research project needs.		We've illustrated how, at one particular instant during a CFD simulation, we can determine the orbital period of our simulated binary star system. With this customized visualization tool in hand, we're in a position to determine how the orbital period and other characteristic frequencies vary with time throughout each simulation. More significantly, we now appreciate how we can modify otherwise standard [http://www.vistrails.org VisTrails] workflows to perform any of a variety of analysis tasks that are customized to our research project needs.




	==<font color="#0000DD">Addenda</font>==		==<font color="#0000DD">Addenda</font>==

Tohline: /* Interpretation of Results */ Added links

2010-02-09T00:31:41Z

Interpretation of Results: Added links

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	==<font color="#0000DD">Interpretation of Results</font>==		==<font color="#0000DD">Interpretation of Results</font>==

	[[Image:Figure2_Tohline.jpg \|border\|center\|600px\|Figure 2. Screenshot of the VisTrails spreadsheet after we used five different values of <font face="Courier">Omega_frame</font> <math>(\Delta \Omega)</math> to execute our customized workflow. Each 3D-rendered image displays eight equatorial-plane streamlines and a pair of isodensity surfaces (lower density surface colored blue; higher density surface colored red) that outline the structure of both stars as well as the connecting mass-transfer stream. The propagation time is the same for all eight streamlines; along six streamlines, VisTrails carries out the integration in both directions from the location marked by a small colored sphere.]]		[[Image:Figure2_Tohline.jpg \|border\|center\|600px\|Figure 2. Screenshot of the [http://www.vistrails.org VisTrails] spreadsheet after we used five different values of <font face="Courier">Omega_frame</font> <math>(\Delta \Omega)</math> to execute our customized workflow. Each 3D-rendered image displays eight equatorial-plane streamlines and a pair of isodensity surfaces (lower density surface colored blue; higher density surface colored red) that outline the structure of both stars as well as the connecting mass-transfer stream. The propagation time is the same for all eight streamlines; along six streamlines, [http://www.vistrails.org VisTrails] carries out the integration in both directions from the location marked by a small colored sphere.]]
	<center>'''Figure 2''' (scroll over image for caption)</center>		<center>'''Figure 2''' (scroll over image for caption)</center>

	Figure 2 displays 3D renderings of the flow from one of our binary mass-transfer simulations as generated by our customized VisTrails workflow. We have generated images assuming five different frame rotation frequencies, as specified by <math>\Delta\Omega</math>. Aside from labeling <math>\Delta\Omega</math> values under each image, we produced Figure 2 by simply taking a screenshot of the VisTrails interactive spreadsheet. The spreadsheet feature has proven to be extremely useful in this analysis because it facilitates the side-by-side comparison of scenes that VisTrails has rendered using different parameter values. And, although we can't demonstrate it here in print, VisTrails lets users zoom, pan, and interactively rotate all 3D-rendered scenes simultaneously.		Figure 2 displays 3D renderings of the flow from one of our binary mass-transfer simulations as generated by our customized [http://www.vistrails.org VisTrails] workflow. We have generated images assuming five different frame rotation frequencies, as specified by <math>\Delta\Omega</math>. Aside from labeling <math>\Delta\Omega</math> values under each image, we produced Figure 2 by simply taking a screenshot of the [http://www.vistrails.org VisTrails] interactive spreadsheet. The spreadsheet feature has proven to be extremely useful in this analysis because it facilitates the side-by-side comparison of scenes that [http://www.vistrails.org VisTrails] has rendered using different parameter values. And, although we can't demonstrate it here in print, [http://www.vistrails.org VisTrails] lets users zoom, pan, and interactively rotate all 3D-rendered scenes simultaneously.

	We'd like to determine which value of <math>\Delta\Omega</math> provides the best measure of the binary star system's true orbital period. As expected, for all five choices of <math>\Delta\Omega</math>, we found the highest velocities (marked by the longest streamlines) along the relatively low-density mass-transfer stream that connects the two stars. Material from the donor star (in the lower half of each rendered image in Figure 2) flows toward its stellar companion, reaching supersonic velocities before impacting the companion. An oblique shock front whose location is delineated by kinks in the pink, blue, and orange streamlines terminates the component of motion perpendicular to the companion's surface. Motion transverse to the shock becomes orbital motion in a thick, low-density disk that surrounds the companion star.		We'd like to determine which value of <math>\Delta\Omega</math> provides the best measure of the binary star system's true orbital period. As expected, for all five choices of <math>\Delta\Omega</math>, we found the highest velocities (marked by the longest streamlines) along the relatively low-density mass-transfer stream that connects the two stars. Material from the donor star (in the lower half of each rendered image in Figure 2) flows toward its stellar companion, reaching supersonic velocities before impacting the companion. An oblique shock front whose location is delineated by kinks in the pink, blue, and orange streamlines terminates the component of motion perpendicular to the companion's surface. Motion transverse to the shock becomes orbital motion in a thick, low-density disk that surrounds the companion star.

Tohline: /* Customized Python Module */ Added links

2010-02-09T00:29:12Z

Customized Python Module: Added links

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	==<font color="#0000DD">Customized Python Module</font>==		==<font color="#0000DD">Customized Python Module</font>==
	To make it possible for us to examine the properties of binary mass-transfer flows from reference frames that have a range of different angular frequencies of rotation, <math>\Omega_\mathrm{frame} = (\Omega_0 + \Delta\Omega)</math>, we wrote a Python-based module <font face="Courier">SwitchCoord</font> for insertion into the base VisTrails workflow. Figure 1c shows our resulting customized VisTrails workflow; it differs very little from the base workflow. The [http://www.vistrails.org/index.php/User:Tohline/CustomizedPythonModule#Sidebar sidebar] shows the complete Python source code from our customized module. The code segment that performs the required ''physics analysis'' is short and straightforward. In particular, the <font face="Courier">SwitchCoord</font> module performs the following operations at each grid vertex:		To make it possible for us to examine the properties of binary mass-transfer flows from reference frames that have a range of different angular frequencies of rotation, <math>\Omega_\mathrm{frame} = (\Omega_0 + \Delta\Omega)</math>, we wrote a Python-based module <font face="Courier">SwitchCoord</font> for insertion into the base [http://www.vistrails.org VisTrails] workflow. Figure 1c shows our resulting customized [http://www.vistrails.org VisTrails] workflow; it differs very little from the base workflow. The [http://www.vistrails.org/index.php/User:Tohline/CustomizedPythonModule#Sidebar sidebar] shows the complete Python source code from our customized module. The code segment that performs the required ''physics analysis'' is short and straightforward. In particular, the <font face="Courier">SwitchCoord</font> module performs the following operations at each grid vertex:
	* converts the <math>(x, y)</math> Cartesian to <math>(R, \phi)</math> cylindrical coordinates;		* converts the <math>(x, y)</math> Cartesian to <math>(R, \phi)</math> cylindrical coordinates;
	* divides the momentum components by density to obtain the velocity components if the density is greater than <font face="Courier">minp</font> (otherwise, it sets the velocity components to zero);		* divides the momentum components by density to obtain the velocity components if the density is greater than <font face="Courier">minp</font> (otherwise, it sets the velocity components to zero);
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	* normalizes the velocities to the maximum velocity <font face="Courier">maxnorm</font> found across the domain where densities are greater than <font face="Courier">minp</font>.		* normalizes the velocities to the maximum velocity <font face="Courier">maxnorm</font> found across the domain where densities are greater than <font face="Courier">minp</font>.

	We designed the output ports on <font face="Courier">SwitchCoord</font> to provide access to the same type of structured arrays that <font face="Courier">vtkPLOT3DReader</font> generates. But, in our customized VisTrails workflow, which includes <font face="Courier">SwitchCoord</font> (see Figure 1c), the 3D vector field that VisTrails pipes into each of the eight <font face="Courier">Draw_Streamline</font> module groups represents the fluid's velocity distribution as viewed from the rotating frame of reference that the floating-point scalar, <font face="Courier">Omega_frame</font>, specifies.		We designed the output ports on <font face="Courier">SwitchCoord</font> to provide access to the same type of structured arrays that <font face="Courier">vtkPLOT3DReader</font> generates. But, in our customized [http://www.vistrails.org VisTrails] workflow, which includes <font face="Courier">SwitchCoord</font> (see Figure 1c), the 3D vector field that [http://www.vistrails.org VisTrails] pipes into each of the eight <font face="Courier">Draw_Streamline</font> module groups represents the fluid's velocity distribution as viewed from the rotating frame of reference that the floating-point scalar, <font face="Courier">Omega_frame</font>, specifies.

	==<font color="#0000DD">Interpretation of Results</font>==		==<font color="#0000DD">Interpretation of Results</font>==

Tohline: /* Base Workflow */ added links

2010-02-09T00:28:11Z

Base Workflow: added links

Tohline: /* Introduction */ Add links to vistrails and to vtk.org

2010-02-09T00:25:06Z

Introduction: Add links to vistrails and to vtk.org

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	Researchers in the open source community are steadily improving scientific visualization tools. These tools are providing a wider array of sophisticated probes for data analysis and a wider assortment of effective user-friendly interfaces. They're also making it easier for researchers in the computational science community — across many disciplines — to effectively analyze huge datasets by drawing on the human brain's acute ability to sort through complex and time-varying visual patterns. The astrophysics group at Louisiana State University (LSU), for example, routinely uses volume-rendering and ray-tracing algorithms in conjunction with animation techniques to examine the time-varying behavior of isodensity surfaces that arise in computational fluid dynamic (CFD) simulations of mass-transferring and merging binary star systems. Although such analyses generally provide only a qualitative identification and assessment of structure within a given dataset, the insight gained from visual inspection can nevertheless be extremely valuable. For example, it was through visual inspection that researchers at LSU initially spotted the nonlinear development of triangular-, square-, and pentagonal-shaped tidal resonances in recent simulations.		Researchers in the open source community are steadily improving scientific visualization tools. These tools are providing a wider array of sophisticated probes for data analysis and a wider assortment of effective user-friendly interfaces. They're also making it easier for researchers in the computational science community — across many disciplines — to effectively analyze huge datasets by drawing on the human brain's acute ability to sort through complex and time-varying visual patterns. The astrophysics group at Louisiana State University (LSU), for example, routinely uses volume-rendering and ray-tracing algorithms in conjunction with animation techniques to examine the time-varying behavior of isodensity surfaces that arise in computational fluid dynamic (CFD) simulations of mass-transferring and merging binary star systems. Although such analyses generally provide only a qualitative identification and assessment of structure within a given dataset, the insight gained from visual inspection can nevertheless be extremely valuable. For example, it was through visual inspection that researchers at LSU initially spotted the nonlinear development of triangular-, square-, and pentagonal-shaped tidal resonances in recent simulations.

	LSU's astrophysics group has begun to incorporate VisTrails into its arsenal of scientific visualization and data analysis tools. VisTrails primarily interested the group a few years ago because it provides a user-friendly workflow interface to the extensive VTK software library. It also automatically tracks the provenance of data analysis efforts. However, what most impresses us now is the ease with which VisTrails facilitates the insertion of home-grown analysis modules into an otherwise VTK-based workflow. Taking advantage of this additional programming versatility, we have gained a greater appreciation of the role that visualization tools can play in the quantitative assessment of results from large-scale simulations. In this article, we first describe the VTK-based workflow that we initially constructed in VisTrails to view streamlines within each binary mass-transfer simulation. We then describe the Python module, whose insertion into this workflow has permitted us to identify values of key rotational frequencies associated with such flows.		LSU's astrophysics group has begun to incorporate [http://www.vistrails.org VisTrails] into its arsenal of scientific visualization and data analysis tools. [http://www.vistrails.org VisTrails] primarily interested the group a few years ago because it provides a user-friendly workflow interface to the [http://www.vtk.org/ extensive VTK software library]. It also automatically tracks the provenance of data analysis efforts. However, what most impresses us now is the ease with which [http://www.vistrails.org VisTrails] facilitates the insertion of home-grown analysis modules into an otherwise VTK-based workflow. Taking advantage of this additional programming versatility, we have gained a greater appreciation of the role that visualization tools can play in the quantitative assessment of results from large-scale simulations. In this article, we first describe the VTK-based workflow that we initially constructed in [http://www.vistrails.org VisTrails] to view streamlines within each binary mass-transfer simulation. We then describe the Python module, whose insertion into this workflow has permitted us to identify values of key rotational frequencies associated with such flows.

	==<font color="#0000DD">Base Workflow</font>==		==<font color="#0000DD">Base Workflow</font>==

Tohline: /* References */ Added links to all five references

2010-02-09T00:21:14Z

References: Added links to all five references

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	===References===		===References===
	# J.E. Tohline, "Scientific Visualization: A Necessary Chore," ''Computing in Science & Eng.,'' vol. 9, no. 6, 2007, pp. 76-81.		# J.E. Tohline, "Scientific Visualization: A Necessary Chore," [http://www.computer.org/portal/web/csdl/doi/10.1109/MCSE.2007.120 ''Computing in Science & Eng.,'' vol. 9, no. 6, 2007, pp. 76-81].
	# M.C.R. D'Souza et al., "Numerical Simulations of the Onset and Stability of Dynamical Mass Transfer in Binaries," ''Astrophysical J.,'' vol. 643, no. 1, 2006, pp. 381-401.		# M.C.R. D'Souza et al., "Numerical Simulations of the Onset and Stability of Dynamical Mass Transfer in Binaries," [http://adsabs.harvard.edu/abs/2006ApJ...643..381D ''Astrophysical J.,'' vol. 643, no. 1, 2006, pp. 381-401].
	# P.M. Motl, et al., "The Stability of Double White Dwarf Binaries Undergoing Direct Impact Accretion," ''Astrophysical J.,'' vol. 670, no. 1, 2007, pp. 1314-1325.		# P.M. Motl, et al., "The Stability of Double White Dwarf Binaries Undergoing Direct Impact Accretion," [http://adsabs.harvard.edu/abs/2007ApJ...670.1314M ''Astrophysical J.,'' vol. 670, no. 1, 2007, pp. 1314-1325].
	# L. Bavoil et al., "Vistrails: Enabling Interactive Multiple-View Visualizations," 2005; www.sci.utah.edu/~csilva/papers/vis2005b.pdf.		# L. Bavoil et al., "Vistrails: Enabling Interactive Multiple-View Visualizations," 2005; [http://www.sci.utah.edu/~csilva/papers/vis2005b.pdf www.sci.utah.edu/~csilva/papers/vis2005b.pdf].
	# S.H. Lubow and F.H. Shu, "Gas Dynamics of Semidetached Binaries," ''Astrophysical J.,'' vol. 198, no. 1, 1975, pp.383-405.		# S.H. Lubow and F.H. Shu, "Gas Dynamics of Semidetached Binaries," [http://adsabs.harvard.edu/abs/1975ApJ...198..383L ''Astrophysical J.,'' vol. 198, no. 1, 1975, pp.383-405].


	===About the Authors===		===About the Authors===

Tohline: /* About the Authors */ Add "mailto" links

2010-02-09T00:09:53Z

About the Authors: Add "mailto" links

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	===About the Authors===		===About the Authors===
	* [http://www.phys.lsu.edu/~tohline/ '''Joel E. Tohline'''] is a professor at Louisiana State University. His research interests include astrophysics, computational fluid dynamics, and high-performance computing. Tohline has a PhD in astronomy from the University of California, Santa Cruz. He's a fellow of the American Association for the Advancement of Science, and a member of the International Astronomical Union, the American Astronomical Society, and the American Physical Society. Contact him at tohline@lsu.edu.		* [http://www.phys.lsu.edu/~tohline/ '''Joel E. Tohline'''] is a professor at Louisiana State University. His research interests include astrophysics, computational fluid dynamics, and high-performance computing. Tohline has a PhD in astronomy from the University of California, Santa Cruz. He's a fellow of the American Association for the Advancement of Science, and a member of the International Astronomical Union, the American Astronomical Society, and the American Physical Society. Contact him at [mailto:tohline@lsu.edu tohline@lsu.edu].
	* [http://www.linkedin.com/pub/jinghua-ge/4/b9a/ba4 '''Jinghua Ge'''] is a visualization consultant at the Center for Computation & Technology (CCT) at Louisiana State University. Her research interests include scientific visualization, computer graphics, and distributed computing. Ge has a PhD in computer science from the University of Illinois, Chicago. Contact her at jinghuage@cct.lsu.edu.		* [http://www.linkedin.com/pub/jinghua-ge/4/b9a/ba4 '''Jinghua Ge'''] is a visualization consultant at the Center for Computation & Technology (CCT) at Louisiana State University. Her research interests include scientific visualization, computer graphics, and distributed computing. Ge has a PhD in computer science from the University of Illinois, Chicago. Contact her at [mailto:jinghuage@cct.lsu.edu jinghuage@cct.lsu.edu].
	* [http://paris.phys.lsu.edu/~weseven/ '''Wesley Even'''] is an NSF/IGERT fellow in the Department of Physics and Astronomy at Louisiana State University. His research focuses on the modeling of mass transfer in double-white-dwarf binary star systems. Contact him at weseven@physics.lsu.edu.		* [http://paris.phys.lsu.edu/~weseven/ '''Wesley Even'''] is an NSF/IGERT fellow in the Department of Physics and Astronomy at Louisiana State University. His research focuses on the modeling of mass transfer in double-white-dwarf binary star systems. Contact him at [mailto:weseven@physics.lsu.edu weseven@physics.lsu.edu].
	* [http://www.sci.utah.edu/~eranders/ '''Erik Anderson'''] is a research assistant and PhD candidate at the University of Utah. His research interests include scientific visualization, signal processing, computer graphics, and multimodal visualization. Anderson has a BS in computer science and a BS in electrical and computer engineering from Northeastern University. Contact him at eranders@sci.utah.edu.		* [http://www.sci.utah.edu/~eranders/ '''Erik Anderson'''] is a research assistant and PhD candidate at the University of Utah. His research interests include scientific visualization, signal processing, computer graphics, and multimodal visualization. Anderson has a BS in computer science and a BS in electrical and computer engineering from Northeastern University. Contact him at [mailto:eranders@sci.utah.edu eranders@sci.utah.edu].

Tohline: /* About the Authors */ Add links to author home pages

2010-02-09T00:04:30Z

About the Authors: Add links to author home pages

← Older revision		Revision as of 00:04, 9 February 2010
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	===About the Authors===		===About the Authors===
	* '''Joel E. Tohline''' is a professor at Louisiana State University. His research interests include astrophysics, computational fluid dynamics, and high-performance computing. Tohline has a PhD in astronomy from the University of California, Santa Cruz. He's a fellow of the American Association for the Advancement of Science, and a member of the International Astronomical Union, the American Astronomical Society, and the American Physical Society. Contact him at tohline@lsu.edu.		* [http://www.phys.lsu.edu/~tohline/ '''Joel E. Tohline'''] is a professor at Louisiana State University. His research interests include astrophysics, computational fluid dynamics, and high-performance computing. Tohline has a PhD in astronomy from the University of California, Santa Cruz. He's a fellow of the American Association for the Advancement of Science, and a member of the International Astronomical Union, the American Astronomical Society, and the American Physical Society. Contact him at tohline@lsu.edu.
	* '''Jinghua Ge''' is a visualization consultant at the Center for Computation & Technology (CCT) at Louisiana State University. Her research interests include scientific visualization, computer graphics, and distributed computing. Ge has a PhD in computer science from the University of Illinois, Chicago. Contact her at jinghuage@cct.lsu.edu.		* [http://www.linkedin.com/pub/jinghua-ge/4/b9a/ba4 '''Jinghua Ge'''] is a visualization consultant at the Center for Computation & Technology (CCT) at Louisiana State University. Her research interests include scientific visualization, computer graphics, and distributed computing. Ge has a PhD in computer science from the University of Illinois, Chicago. Contact her at jinghuage@cct.lsu.edu.
	* '''Wesley Even''' is an NSF/IGERT fellow in the Department of Physics and Astronomy at Louisiana State University. His research focuses on the modeling of mass transfer in double-white-dwarf binary star systems. Contact him at weseven@physics.lsu.edu.		* [http://paris.phys.lsu.edu/~weseven/ '''Wesley Even'''] is an NSF/IGERT fellow in the Department of Physics and Astronomy at Louisiana State University. His research focuses on the modeling of mass transfer in double-white-dwarf binary star systems. Contact him at weseven@physics.lsu.edu.
	* '''Erik Anderson''' is a research assistant and PhD candidate at the University of Utah. His research interests include scientific visualization, signal processing, computer graphics, and multimodal visualization. Anderson has a BS in computer science and a BS in electrical and computer engineering from Northeastern University. Contact him at eranders@sci.utah.edu.		* [http://www.sci.utah.edu/~eranders/ '''Erik Anderson'''] is a research assistant and PhD candidate at the University of Utah. His research interests include scientific visualization, signal processing, computer graphics, and multimodal visualization. Anderson has a BS in computer science and a BS in electrical and computer engineering from Northeastern University. Contact him at eranders@sci.utah.edu.

Tohline: Add link to CiSE article and delete ref. 6

2010-02-08T23:56:29Z

Add link to CiSE article and delete ref. 6

← Older revision		Revision as of 23:56, 8 February 2010
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	<table border=1 cellpadding=10 width="95%" align="center">		<table border=1 cellpadding=10 width="95%" align="center">
	<tr><td>		<tr><td>
	<b><font color="#880000">Most of the content of this Wiki document initially appeared in print as a ''Visualization Corner'' article in the May/June 2009 issue of ''Computing in Science & Engineering ''</font></b> ~~[6]~~.		<b><font color="#880000">Most of the content of this Wiki document initially appeared in print as a [http://www.computer.org/portal/web/csdl/doi/10.1109/MCSE.2009.44 ''Visualization Corner'' article in the May/June 2009 issue of ''Computing in Science & Engineering'']</font></b>.
	</td></tr>		</td></tr>
	</table>		</table>
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	# L. Bavoil et al., "Vistrails: Enabling Interactive Multiple-View Visualizations," 2005; www.sci.utah.edu/~csilva/papers/vis2005b.pdf.		# L. Bavoil et al., "Vistrails: Enabling Interactive Multiple-View Visualizations," 2005; www.sci.utah.edu/~csilva/papers/vis2005b.pdf.
	# S.H. Lubow and F.H. Shu, "Gas Dynamics of Semidetached Binaries," ''Astrophysical J.,'' vol. 198, no. 1, 1975, pp.383-405.		# S.H. Lubow and F.H. Shu, "Gas Dynamics of Semidetached Binaries," ''Astrophysical J.,'' vol. 198, no. 1, 1975, pp.383-405.
	~~# <span name="ref6">J.E. Tohline et al., "A Customized Python Module for CFD Flow Analysis within VisTrails," ''Computing in Science & Eng.,'' vol. 9, no. 6, 2009, pp. 68-73.</span>~~

	===About the Authors===		===About the Authors===

← Older revision		Revision as of 00:28, 9 February 2010
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	<center>'''Figure 1:''' (scroll over image for caption)</center>		<center>'''Figure 1:''' (scroll over image for caption)</center>

	Within VisTrails, we initially selected various VTK-based modules to do the following, in sequence (see Figure 1a):		Within [http://www.vistrails.org VisTrails], we initially selected various VTK-based modules to do the following, in sequence (see Figure 1a):
	*''Read simulation data.'' We used <font face="Courier">vtkPLOT3DReader</font> to read in one file containing the <math>(x, y, z)</math> coordinate locations of every vertex on our 3D cylindrical coordinate mesh and a separate file containing the fluid's mass-density (scalar) and momentum-density (3D vector) at every grid vertex.		*''Read simulation data.'' We used <font face="Courier">vtkPLOT3DReader</font> to read in one file containing the <math>(x, y, z)</math> coordinate locations of every vertex on our 3D cylindrical coordinate mesh and a separate file containing the fluid's mass-density (scalar) and momentum-density (3D vector) at every grid vertex.
	*''Outline cylindrical domain boundary.'' As shown, we enlisted <font face="Courier">vtkStructuredGridOutlineFilter</font>, <font face="Courier">vtkPolyDataMapper</font>, and <font face="Courier">vtkActor</font>.		*''Outline cylindrical domain boundary.'' As shown, we enlisted <font face="Courier">vtkStructuredGridOutlineFilter</font>, <font face="Courier">vtkPolyDataMapper</font>, and <font face="Courier">vtkActor</font>.
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	*''Draw streamlines.'' As Figure 1b shows, each of the eight separate <font face="Courier">Draw_Streamlines</font> module groups uses <font face="Courier">vtkStreamLine</font>, <font face="Courier">vtkTubeFilter</font>, <font face="Courier">vtkDataSetMapper</font>, <font face="Courier">vtkProperty</font>, <font face="Courier">vtkActor</font>, <font face="Courier">vtkSphereSource</font>, <font face="Courier">vtkPolyDataMapper</font>, and <font face="Courier">vtkLODActor</font> to trace an individual streamline within the flow. Streamline lengths are set by feeding a common <font face="Courier">Propagation_Time</font> into all eight module groups.		*''Draw streamlines.'' As Figure 1b shows, each of the eight separate <font face="Courier">Draw_Streamlines</font> module groups uses <font face="Courier">vtkStreamLine</font>, <font face="Courier">vtkTubeFilter</font>, <font face="Courier">vtkDataSetMapper</font>, <font face="Courier">vtkProperty</font>, <font face="Courier">vtkActor</font>, <font face="Courier">vtkSphereSource</font>, <font face="Courier">vtkPolyDataMapper</font>, and <font face="Courier">vtkLODActor</font> to trace an individual streamline within the flow. Streamline lengths are set by feeding a common <font face="Courier">Propagation_Time</font> into all eight module groups.

	~~Vistrails~~ renders the output from the various workflow actors in a composite scene using <font face="Courier">vtkRenderer</font> as viewed by an observer located at a position that <font face="Courier">vtkCamera</font> specifies. Finally, the module <font face="Courier">vtkCell</font> directs this scene to the VisTrails interactive spreadsheet.		[http://www.vistrails.org VisTrails] renders the output from the various workflow actors in a composite scene using <font face="Courier">vtkRenderer</font> as viewed by an observer located at a position that <font face="Courier">vtkCamera</font> specifies. Finally, the module <font face="Courier">vtkCell</font> directs this scene to the VisTrails interactive spreadsheet.

	In this initially constructed ''base workflow,'' VisTrails pipes the 3D vector field representing the momentum density distribution from the <font face="Courier">vtkPLOT3DReader</font> module directly into each of the eight <font face="Courier">Draw_Streamline</font> module groups. This base workflow — which VisTrails assembles using generically available <font face="Courier">vtk</font> modules — lets us examine the behavior of streamlines in our binary mass-transfer simulations, but only from the frame of reference, <math>\Omega_0</math>, in which we originally performed each simulation (see Figure 2b, labeled <math>\Delta\Omega = 0.00</math>).		In this initially constructed ''base workflow,'' [http://www.vistrails.org VisTrails] pipes the 3D vector field representing the momentum density distribution from the <font face="Courier">vtkPLOT3DReader</font> module directly into each of the eight <font face="Courier">Draw_Streamline</font> module groups. This base workflow — which [http://www.vistrails.org VisTrails] assembles using generically available <font face="Courier">vtk</font> modules — lets us examine the behavior of streamlines in our binary mass-transfer simulations, but only from the frame of reference, <math>\Omega_0</math>, in which we originally performed each simulation (see Figure 2b, labeled <math>\Delta\Omega = 0.00</math>).

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	'''<font size="+1"color="darkblue">TERMINOLOGY</font>'''<br>		'''<font size="+1"color="darkblue">TERMINOLOGY</font>'''<br>
	One well-defined characteristic of a binary star system is it orbital period, <math>P</math>. If the stars are in circular orbit around one another, a binary system will appear to be stationary when viewed from a frame that's rotating with an angular frequency <math>\Omega_\mathrm{frame} = 2\pi/P</math>. When modeling mass-transferring binary star systems, we've found it advantageous to perform each computational fluid dynamic (CFD) simulation on a cylindrical-coordinate grid that rotates with a frequency <math>\Omega_0 = 2\pi/P_0</math>, where <math>P_0</math> is the binary system's orbital period at the beginning of the simulation. As mass and angular momentum are transferred from one star to the other throughout the simulation, however, the binary system's orbital period and associated value of <math>\Omega_\mathrm{frame}</math> will vary. As explained in the main text, we used VisTrails to measure <math>\Delta\Omega = (\Omega_\mathrm{frame} - \Omega_0)</math> and, hence, the instantaneous orbital period <math>P = P_0/(1 + P_0 \Delta\Omega/2\pi)</math> at any time during a simulation.		One well-defined characteristic of a binary star system is it orbital period, <math>P</math>. If the stars are in circular orbit around one another, a binary system will appear to be stationary when viewed from a frame that's rotating with an angular frequency <math>\Omega_\mathrm{frame} = 2\pi/P</math>. When modeling mass-transferring binary star systems, we've found it advantageous to perform each computational fluid dynamic (CFD) simulation on a cylindrical-coordinate grid that rotates with a frequency <math>\Omega_0 = 2\pi/P_0</math>, where <math>P_0</math> is the binary system's orbital period at the beginning of the simulation. As mass and angular momentum are transferred from one star to the other throughout the simulation, however, the binary system's orbital period and associated value of <math>\Omega_\mathrm{frame}</math> will vary. As explained in the main text, we used [http://www.vistrails.org VisTrails] to measure <math>\Delta\Omega = (\Omega_\mathrm{frame} - \Omega_0)</math> and, hence, the instantaneous orbital period <math>P = P_0/(1 + P_0 \Delta\Omega/2\pi)</math> at any time during a simulation.
	</td></tr>		</td></tr>
	</table>		</table>