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## Built-in queries

The following table lists the query name, type, and description for the built-in queries that VisIt supports. The query type for database queries, point queries, and line queries are respectively marked as: DB, Point, and Line.

Query name | Query type | Description
--- | --- | ---
2D area | DB | The 2D area query calculates the area of the 2D plot highlighted in the Plot list and prints the result to the Query results. VisIt can produce a Curve plot of this query with respect to time.
3D surface area | DB | The 3D surface area calculates the area of the plot highlighted in the Plot list and prints the result to the Query results. VisIt can produce a Curve plot of this query with respect to time.
Area Between Curves | DB | The Area Between Curves query calculates the area between 2 curve plots. The plots that will serve as input to this query must both be highlighted in the Plot list or VisIt will issue an error message. Once the area has been calculated, the result is printed to the Query results.
Centroid | DB | This query will calculate the centroid of a dataset. The contribution of each cell is calculated assuming its mass all lies at the center of the cell. If the query is performed on a Pseudocolor plot, the plot's variable will be assumed to be density. If the query is performed on a plot such as a Mesh plot or FilledBoundary plot, uniform density will be used. The results are print to the Query results.
Chord Length Distribution | DB | The Chord Length Distribution query calculates a probability density function of chord length over a two or three dimensional object. Axially symmetric objects (RZ-meshes) are treated as 3D meshes and chords are calculated over the revolved, 3D object. A statistical approach, casting uniform density, random lines, is used. The result of this query is a curve, which is outputted as a separate file. This curve is a probability density function over length scale. The name of the resulting file is printed to the Query results.
Compactness | DB | The Compactness query calculates mesh metrics and prints them in the Query results.
Cycle | DB | The Cycle query prints the cycle for the plot that is highlighted in the Plot list to the Query results.
Distance from Boundary |  | The Distance From Boundary query calculates how much mass is at a given distance away from the boundary of a shape. An important distinction for this query is that distance from the boundary (for a given point) is not defined as the shortest distance to the boundary, but simultaneously as all surrounding distances. Axially symmetric objects (RZ-meshes) are treated as 3D meshes and length scales are calculated over the revolved, 3D object. The implementation employs a statistical approach, with the casting of uniform density, random lines. The result of this query is a curve, which is outputted as a separate file. This curve contains the amount of mass as a function of length scale. Integrating the curve between P0 and P1 will give the total mass at distance between P0 and P1 (given the interpretation above). The name of the resulting file is printed to the Query results.
Eulerian |  | The Eulerian query calculates the Eulerian number for the mesh that is used by the highlighted plot in the Plot list. The results are printed to the Query results.
Expected Value | DB | The Expected Value query calculates the integral of xf(x)dx for some curve f(x). The curve should be highlighted in the Plot list and prints the result to the Query results. This query is intended for distribution functions.
Integrate | DB | The Integrate query calculates the area under the Curve plot that is highlighted in the Plot list and prints the result to the Query results.
Kurtosis | DB | The Kurtosis query calculates the kurtosis of a normalized distribution function. The normalized distribution function must be represented as a Curve plot in VisIt. Kurtosis measures the variability of a distribution by comparing the ratios of the fourth and second central moments. The results are print to the Query results.
L2Norm | DB | The L2Norm query calculates the L2Norm, or square of the integrated area, of a Curve plot. The Curve plot must be highlighted in the Plot list. The results are printed to the Query results.
L2Norm Between Curves | DB | The L2Norm query takes two Curve plots as input and calculates the L2Norm between the 2 curves. Both Curve plots must be highlighted in the Plot list or VisIt will issue an error message. The results are printed to the Query results.
Lineout | Line | The Lineout query creates a new instance of the highlighted plot in the Plot list, applies a Lineout operator, and copies the plot to another vis window. The properties of the Lineout operator such as the start and end points are set using the controls in the Query parameters area of the Query Window. Creating Lineouts in this manner instead of using VisIt's interactive lineout allows you to create 1D Curve plots from 3D databases.
Min | DB | The Min query calculates the minimum value for the variable used by the highlighted plot in the Plot list and prints the value and the logical and physical coordinates where the minimum value was found to the Query results.
Mass Distribution | DB | The Mass Distribution query calculates how much mass occurs at different length scales over a two or three dimensional object. Axially symmetric objects (RZ-meshes) are treated as 3D meshes and length scales are calculated over the revolved, 3D object. The implementation employs a statistical approach, with the casting of uniform density, random lines. The result of this query is a curve, which is outputted as a separate file. This curve contains the amount of mass as a function of length scale. Integrating the curve between P0 and P1 will give the total mass between length scale P0 and length scale P1. The name of the resulting file is printed to the Query results.
Max | DB | The Max query calculates the maximum value for the variable used by the highlighted plot in the Plot list and prints the value and the logical and physical coordinates where the maximum value was found to the Query results.
MinMax | DB | The MinMax query calculates the minimum and maximum values for the variable used by the highlighted plot in the Plot list and prints the values and their logical and physical coordinates in the Query results.
Moment of inertia | DB | This query will calculate the moment of inertia tensor for each cell in a three-dimensional dataset. The contribution of each cell is calculated assuming its mass all lies at the center of the cell. If the query is performed on a Pseudocolor plot, the plot's variable will be assumed to be density. If the query is performed on a plot such as a mesh plot or FilledBoundary plot, uniform density will be used. The results are printed to the Query results.
NodeCoords | DB | The NodeCoords query prints the node coordinates for the specified node and prints the values in the Query results.
NodePick | Point | The NodePick query performs node picking at the specified world coordinate which, if used in 3D, need not be on the surface of a 3D dataset.The plot to be picked must be highlighted in the Plot list. Information about the picked node, if there is one, is printed to the Query results and the Pick Window.
NumNodes | DB | The NumNodes query prints the number of nodes for the mesh used by the highlighted plot in the Plot list to the Query results.
NumZones | DB | The NumZones query prints the number of zones for the mesh used by the highlighted plot in the Plot list to the Query results.
Pick | Point | The Pick query performs zone picking at the specified world coordinate which, if used in 3D, need not be on the surface of a 3D dataset.The plot to be picked must be highlighted in the Plot list. Information about the picked node, if there is one, is printed to the Query results and the Pick Window.
PickByNode | Point | The PickByNode query performs node pick using the highlighted plot in the Plot list and specified domain and node values. You can give a global node number if you turn on the Use Global Node check box. A pick point is added to the vis window and the query results appear in the Query results and the Pick Window. Note: this is the query to use if you want to query the database for the value of a variable at a certain node. VisIt can produce a Curve plot of this query with respect to time.
PickByZone | Point | The PickByZone query performs zone pick using the highlighted plot in the Plot list and specified domain and zone values. You can give a global node number if you turn on the Use Global Zone check box. A pick point is added to the vis window and the query results appear in the Query results and the Pick Window. Note: this is the query to use if you want to query the database for the value of a variable at a certain cell. VisIt can produce a Curve plot of this query with respect to time.
Revolved surface area | DB | The Revolved surface area query revolves the mesh used by the highlighted plot in the Plot list about the X-axis and prints the plot's revolved surface area to the Query results.
Revolved volume | DB | The Revolved volume area query revolves the mesh used by the highlighted plot in the Plot list about the X-axis and print's the plot's volume to the Query results.
Skewness | DB | The Skewness query calculates the skewness of a normalized distribution function. The normalized distribution function must be represented as a Curve plot in VisIt. Skewness measures the symmetry of a distribution using its second and third central moments. The results are print to the Query results.
Spatial Extents | DB | The Spatial Extents query calculates the original or actual spatial extents for the plot that is highlighted in the Plot list. Whether the original or actual extents are calculated is determined by setting the options in the Query parameters area. The spatial extents are printed to the Query results when the query has finished.
Spherical compactness factor | DB | This query attempts to measure how spherical a three dimensional shape is. The query first determines what the volume of a shape is. It then constructs a sphere that has that same volume. Finally, the query positions the sphere so that the maximum amount of the original shape is within the sphere. The query returns the percentage of the original shape that is contained within the sphere. The results are print to the Query results. VisIt can produce a Curve plot of this query with respect to time.
Time | DB | The Time query prints the time for the plot that is highlighted in the Plot list to the Query results.
Variable Sum | DB | The Variable Sum query adds up the variable values for all cells using the plot highlighted in the Plot list and prints the results to the Query results. VisIt can produce a Curve plot of this query with respect to time.
Volume | DB | The Volume query calculates the volume of the mesh used by the plot highlighted in the Plot list and prints the value to the Query results. VisIt can use this query to produce a Curve plot of volume with respect to time.
Watertight | DB | The Watertight query determines if a three-dimensional surface mesh, of the plot highlighted in the Plot list, is "watertight", meaning that it is a closed volume with mesh connectivity such that every edge is indicident to exactly two faces. This means that no edge can have a duplicate in the exact same position. The result of the query is printed in the Query results.
Weighted Variable Sum | DB | The Weighted Variable Sum query adds up the variable values, weighted by cell size, for all cells using the plot highlighted in the Plot list and prints the results to the Query results. VisIt can produce a Curve plot of this query with respect to time.
ZoneCenter | DB | The ZoneCenter query calculates the zone center for a certain cell in the database used by the highlighted plot in the Plot list. The cell center is printed to the Query results and the Pick Window.