Advanced Data Analysis

Introduction

This tutorial covers data analysis.

Find Data dialog

The Find Data dialog box is used to select points or cells, to show the data for these points or cells, to control label display on your data in the 3d view, and as a shortcut to run data analysis filters. We will explore this dialog box using an example.

• Open a dataset and the Find Data dialog.
  • Open the dataset can.exo. Turn on all variables. Apply.
  • Edit/ Find Data. You can also open the Find Data dialog using the icon
• We will select a GlobalElementId.
  • Find Cells from can.ex2
  • Change pulldown to GlobalElementId. Leave as is. Enter 100.
  • Run Selection Query

• We will select two GlobalElementIds.
  • Find Cells from can.ex2
  • Change pulldown to GlobalElementId. Change to is one of. Enter 100, 102.
  • Run Selection Query

• We will select the maximum EQPS.
  • Move forward one timestep. EQPS for timestep 0 is all the same - 0.
  • Find Cells from can.ex2
  • Change pulldown to EQPS. Change to is max.
  • Run Selection Query
  • Play forward

Notice that the data for the selected cell (or point) is displayed in the spreadsheet.

If desired, the maximum (or minimum) cell can be found, and this selection can be frozen. The same cell will then be selected for all timesteps. Use the Freeze Selection button to freeze selections.

• Select Block Id, "is", and then select the .... At present, ParaView requires it's internal structure number. Select block 1, then OK. (The number 2 will appear in the window.)
• Run Selection Query.
• If desired, you can Extract Selection or Plot Selection Over Time (only on single points or cells)..

Data Analysis - Point Labels

• Open the data set can.exo.
• Change the Style Representation to Surface With Edges.
• On the toolbar, push the Select Points On icon. This will allow you to manually select a point on your data set and have the id of those points displayed.
• Rubber band select a point (node)
• From the View menu select the menu option Selection Inspector.
• Notice that all of the point indexes are listed.
• On the Selection Inpector panel, scroll down to the bottom and click on the Point Label tab. Check the Visible check box. This will display the point IDs on the data set.
• You can also do a lookup in the opposite direction.
• On the Selection Inspector panel, scroll to the top and enter an Index Range or Global ID Range number. On can.exo, an example is Composite ID 2 (first generic block), and point 100. It will display on your dataset.
• Try toggling the Select Cells that Include the Selected Point on.
• HINT – change to wireframe to find the points or cells you have selected.
• Extra Credit – Try the same selection steps with cell type data. For a cell number, try Composite ID 2, cell 100.

Data Analysis - Spreadsheet and histogram view

• Open Can.exo.
• Highlight the can window, and Select Cell on the can.
• Split Horizontal
• Split Vertical
• In the upper right window, select Spreadsheet View.
• Change the Attributes to Cell Data. Return it to Point Data.
• Select the Show Only Selected Elements check box (next to Precision).
• Note that the Spreadsheet can now be sorted - including in parallel.
• Select a different cell on the can.
• Highlight the lower right window.
• Filters→Data Analysis→Histogram. Apply.
• Change Scalars to DISPL. Apply.
• Animate forward in time one step at a time.
• Play

Data Analysis - Advanced Spreadsheets

• You can either display all of your dataset's points or cells in your spreadsheet, or only those that are selected in the 3d view. With the spreadsheet window selected, on the Display tab, click Show only selected elements.
• When cells or points are selected in the 3d window, the appropriate row(s) in the spreadsheet view will be highlighted.
• Highlighting works both ways - if you select a row or rows in the spreadsheet view, the cell or point on your dataset will be selected.
• You can select multiple rows in the spreadsheet by holding down the <ctrl> key, and can select ranges of rows by holding down the <shft> key.
• Note that the Spreadsheet can now be sorted - including in parallel.

Data Analysis - Frustrum

• When you are using the Select Cells Through or Select Points Through, it is possible to see the frustrum (the 3d space you selected). Turn on View/ Selection Inspector , then Selection Type - Frustrum, then click the Show Frustrum check box.

Data Analysis - Extract Selection

• Open can.exo.
• On the toolbar, push the Select Cells On icon. This will allow you to manually select a cell on your data set.
• Click on the can in one location, turning on only one cell.
• Filters→Data Analysis→Extract Selections, then click the Copy Active Selection button, and Apply.
• Split Vertical, Spreadsheet View, and turn on the eyeball in front of the ExtractSelection filter.
• You can see Cell data by selecting the ExtractSelection→Display tab and changing the Select Attributes to Show.
• Try animating the data.
• Extra Credit: Turn on visibility of the can, and display it in wireframe. Change the color of the selected cell to Red. (The following picture is including the extra credit.)

Data Analysis - Spreadsheet data by time

• Open can.exo.
• On the toolbar, push the Select Points On icon. This will allow you to manually select a point on your data set.
• Rubber band select a point, turning on only one point.
• Filters→Data Analysis→Plot Selection Over Time, then click the Copy Active Selection button, and Apply.
• Split Vertical, Spreadsheet View, and with the Spreadsheet View highlighted, turn on the eyeball in front of the PlotSelectionOverTime filter.
• Note that you can then write this data out to a .csv file using File → Export.

Acknowledgements

Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.