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Starting the Tutorial

To start the tutorial you will open a datafile and display an initial plot in the vis window.

· Start MeshTV by typing meshtv at the prompt.

· Bring up the File selection window and select all the files in the directory
/usr/local/meshtv/data matching the filter *.silo .

· Select the file ucd3d.silo .

· Select a pseudocolor plot of "d," a mesh plot of "ucdmesh3d," and a boundary plot of "mat1."

· Select the "Orthogonal slice" operator from the Operators pulldown menu.

· Make the plots visible by pressing the Draw button.

Opening Three Windows

You are now ready to open three windows. You will create four windows and then delete the fourth one so that you are left with the desired three windows.

· Select "2 x 2" from the Layout pullright menu from the Window pulldown menu on the MeshTV Main window.

Four smaller windows will now appear on the screen, laid out in a 2 by 2 grid in the upper right hand corner of the screen. You can now delete the fourth window.

· Select "4" from the Active Window setting on the MeshTV Main window.

· Select "Delete" from the Window pulldown menu on the MeshTV Main window.

The fourth window will now be deleted.

Changing the Current Window

You will now make window 2 current.

· Select "2" from the Active Window setting on the MeshTV Main window.

Since this is the first time that you have referenced window 2, the properties from window 1 were copied to window 2.

You are now going to remove the mesh and change the pseudocolor plot variable.

· Highlight the mesh plot from the Active plots scrolling list.

· Press the Delete button above the Active plots scrolling list.

· Highlight the pseudocolor plot from the Active plots scrolling list.

· Select "p" from the Variable pulldown menu.

· Press the Draw button.

Performing the Line-out Operation

MeshTV's line-out functionality allows you to draw lines (called reference lines) on a plot with the mouse that generates a curve that contains the values of a variable as a function of distance along the reference line. The values vs. distance line that MeshTV draws in a second vis window is called a curve plot. The visualization window that receives the curve plot is specified in the Line-out window accessible from the Controls menu on the MeshTV Main window. The variable being plotted is the variable associated with the first highlighted plot in the Active plots list.

You will now make some line-outs of the variable "p" from window 1.

· Select "Line-out" from the Controls pulldown menu on the MeshTV Main window.

· Change the Output Window text field from 2 to 3 .

· Press the Apply button.

· Press the Dismiss button.

· Select " 1" from the Active Window setting on the MeshTV Main window.

· Highlight the pseudocolor plot in the Active Plots scrolling list.

· Place the mouse over the vis window (the window with the image.) When you hold down the right mouse button, a menu will pop up. Put your mouse over the "Mode" selection and move it over the arrow to the right of the word. Another menu will pop up. Select "Line-out" from that.

You are now ready to make some line-outs.

· Move the cursor into window 1 over the plots.

· Press and hold the left mouse button at the first end point of the line.

· As you move the cursor, a line will be displayed showing the line that will be used for the reference line plot.

· Release the mouse button when the second end point is in the correct location.

· A curve plot of the variable versus distance along the selected line will appear in window 3.

· You can create several more lines in window 1, resulting in more curves in window 3. Window 1 will stay in Line-out mode until it is changed.

You can change the way the line-out is done.

· Select "Line-out" from the Controls pulldown menu on the MeshTV Main window.

· Click on the Logical toggle button so that it is "pressed in."

· Press the Apply button.

· Press the Dismiss button.

· Make sure window 1 is still the active window and highlight the pseudocolor plot in the Active Plots scrolling list.

· Move the cursor into window 1 over the plots.

· Press and hold the left mouse button at the first end point of the line.

· As you move the cursor, a line will be displayed showing the line that will be used for the reference line plot.

· Release the mouse button when the second end point is in the correct location. Notice that the line moves so that it follows the mesh. This is because we switched the line-out mode into "logical" mode (following the mesh) rather than using "absolute" mode (a straight line between two coordinates).

· A curve plot of the variable versus distance along the selected line will appear in window 3.

Using Pick and Query

The pick and query feature allows the users to inquire about data within computational zones within the mesh. The data is presented as it exists in the datafile without interpolation or manipulation. The variable being picked is the same variable that is associated with the first highlighted plot in the Active plots list. You can use pick to inquire about material, mesh, and scalar variables but not vectors.

You will now pick the variable "d" from window 1.

· Select "Pick" from the "Mode" pullright menu from the popup menu from vis window 1.

You are now ready to query values.

· Move the cursor into window 1 over the plots.

· Press and release any mouse button over the position you want to query.

· The result of the query will appear in the Output window.

· Query several more points in the plot.

· You may continue querying points as long as you are in pick and query mode. The vis window will stay in pick and query mode until it is changed.

Using the Command Line Interface

Commands can be sent directly to the command line interface, bypassing the graphical user interface (GUI), by typing into the Command Line Interface text field on the MeshTV Main window. Any commands that the command line interface accepts can be entered in the text field. The commands are not interpreted by the GUI, and therefore, the GUI will not reflect changes made through the command line interface. Commands that will impact the state of the GUI should only be used with great caution.

The following is a list of commands that are safe to use in the command line interface. The syntax of the commands can be found in the " MeshTV Command Line Interface Manual " document.

• alias - Define or list command aliases.
• area - Define area properties for 3D plots.
• cat - Print the contents of the given file to Output window.
• clear - Remove all plots from the given vis window.
• ct - Set the color table for the current window.
• end - Exit from the MeshTV session and remove all subordinate windows.
• help - Print a command list or a brief summary of one command.
• inq - Inquire the current database attributes.
• latitude - Set the 3D viewing parameter, latitude.
• longitude - Set the 3D viewing parameter, longitude.
• matcol - Assign the material-color correspondence.
• minmax - Print a variable's minimum and maximum data values.
• pan3 - Perform a relative pan 3D viewing operation.
• panf3 - Perform an absolute pan 3D viewing operation.
• printwin - Print the current vis window on the network color printer.
• rotx - Rotate a 3D object about the X-axis.
• roty - Rotate a 3D object about the Y-axis.
• rotz - Rotate a 3D object about the Z-axis.
• sh - Execute an operating system (shell) command.
• source - Process a command input file.
• unalias - Remove the definition of a command alias.
• wp - Set the 2D plotting window using physical coordinates.
• wp3 - Set the 3D plotting window using physical coordinates.
• zoom3 - Set the 3D relative zoom factor.
• zoomf3 - Set the 3D absolute zoom factor.

Using the Expressions window

The Expressions window is used to define new variables from existing variables. To define a new expression, you must specify the variable name, the expression that defines the new variable, and the type of the variable. The operators used in defining expressions can be found in the section on the defvar command in the " MeshTV Command Line Interface Manual " document. A short list is provided below.

Function or operator	Meaning
{}	The grouping operator. Used for building vectors.
+, -, *, /, ^	The standard arithmetic operators.
absv	Absolute value.
sqrt	Square root.
ln	Natural log.
log	Base-10 log.

The variable type is used to check errors and determine which plots can display the variable.

Variable type	Plots that use the variable type
Constant	None (A constant expression that cannot be plotted, e. g. 3.14159)
Material	Boundary, Filled boundary
Mesh	Mesh
Point	Point
Scalar	Contour, Pseudocolor, Surface
Vector	Vector

You will now define some new variables.

· Select "Expressions" from the Controls pulldown menu on the MeshTV Main window.

· Enter d2 into the second text field under the Name label and press the <Tab>  key.

· Enter 2 * d and press the <Tab> key.

· Enter mom and press the <Tab> key.

· Enter d * {u, v} .

· Set the Type to "Vector."

· Press the Apply button followed by the Dismiss button.

You have now defined two new variables. If you bring up the variable pullright menu from the "Contour" entry from the Plot pulldown menu on the MeshTV Main window, you should see an entry for "d2." If you bring up the variable pullright menu from the "Vector" entry from the Plot pulldown menu, you should see an entry for "mom."

Exiting the Tutorial

You can now exit MeshTV.

· Select "Quit" from the File pulldown menu on the MeshTV Main window.