Datatable View

Datatable view

The datatable view displays a table of a track's data. It has its own toolbar for selecting the track and visible data columns. The data displayed in the table can be analyzed with the Data Tool or copied to the clipboard for pasting into a spreadsheet or other application.

1. Controlling auto-refresh

By default, datatables are refreshed automatically when changes in data occur (e.g. when marking points). But when working with very long videos it can be useful to turn off auto-refresh in order to speed up the marking process. To turn off auto-refresh, click the Refresh button on the toolbar and uncheck the Auto-refresh item in the popup menu. When done marking, turn auto-refresh back on or refresh the data manually by choosing the Refresh item in the popup menu.

Refresh menu

2. Selecting a track

Select a track from the dropdown list on the datatable view's toolbar.

Selecting a track

3. Selecting visible columns

Select the columns displayed in the table by clicking the Data button and checking the columns of interest. The time column is always displayed.

Selecting data columns Data columns displayed in table

Cells for which no data exist are empty. In particular, velocities and accelerations cannot be determined at the beginning, end, or where there are gaps in the position data.

Selecting data columns Data columns displayed in table

4. Sorting rows

Click a column header to sort rows in ascending order of the data in the clicked column. The sorted column name is displayed in bold font.

Sorted column

5. Finding and filling data gaps

Sometimes steps are skipped when marking, by accident or otherwise. It is recommended you identify and eliminate these data gaps since they prevent Tracker from calculating velocities and accelerations. The datatable can help make this easier by (a) drawing red lines where the gaps occur or (b) filling the gaps using linear interpolation.

When Tracker detects that there are missing steps (as in the table below, where step 2 is missing) a gaps button is displayed on the table's toolbar and by default the gaps are shown in red. Click the gaps button and check/uncheck the Show data gaps and/or Autofill data gaps boxes as desired. For more information see Point Mass Handling data gaps. For data gap preferences see preferences dialog.

Gaps shown in red Gaps button showing gaps

6. Formatting data columns

By default, the format of a number displayed in a table varies based on the magnitude of the number. If desired, you can set a fixed format using the Number Format dialog. To display the Number Format dialog right-click the datatable and select Number Format... from the popup menu. For more information see Number Formats.

7. Selecting cells

Click and drag in the table to select cells. Double-click any cell to select all cells, or double-click a column header to select that column.

Control-click a cell to add or remove that row and column to or from the current selection. Control-click a column header to add or remove that column to or from the current selection.

Shift-click a cell to add that and all intervening rows and columns to the current selection. Shift-click a column to add that and all intervening columns to the current selection.

Selecting cells Selecting a column

Click the blank area below the data table to deselect all cells.

8. Copying data

Right-click the table and select Copy Selected Data from the popup menu to copy the selected cells to the clipboard. On Mac, select one cell, then hold down both the shift and control keys while clicking on a second cell to select the enclosed range and pop up the Copy menu.

Cell values may be copied in full precision scientific notation or using the format displayed in the table.

Copying the data

By default, cells are copied as text strings delimited by tabs between columns and line returns between rows. You can change the column delimiter using the Set Delimiter menu as shown.

Setting the delimiter

9. Defining text columns

Right-click the table and choose Text Columns|Create... to create a new editable text column. You must assign the column a name that is not already in use.

Creating a text column Naming a text column

To enter text in a text column cell, just click the cell, type in the text, and hit the enter key. Note: text entries do not need to be numbers, but if all entries in a text column are numbers then the column can be analyzed as data in the Data Tool or when copied and pasted into a spreadsheet. Non-numerical entries can still be copied and pasted (as text), but cannot be analyzed in the Data Tool.

Entering text in a text column cell

Text column cells exist only alongside other track data--i.e., you cannot enter text for times that are not marked and displayed.

To delete or rename a text column, choose the column name from the appropriate Text Columns popup menu.

Deleting a text column

10. Defining new data columns with Data Builder

Right-click the table and choose Define... to display a Data Builder with which you can define custom variables called data functions for plots and datatables.

Click the appropriate Add button to add new data functions or to define parameters for use in function expressions.

Adding a data function Gravitational potential energy function

Data functions can be virtually any mathematical function of parameters, track-defined data columns, and other data functions.

Data Builder help

11. Saving, loading and autoloading data functions

Data functions created with Data Builder can be saved in XML files for manual or automatic loading. To save a function for manual loading, click the save button on the Data Builder toolbar, select the functions to save in the Save Data Functions dialog, and click the OK button. To manually load a saved data function, click the open button on the Data Builder toolbar, open the XML file with the file chooser, then select the functions to load. Note: data functions are associated with a specific track type and cannot be loaded into other track types--e.g., a function defined and saved by a Point Mass track can be loaded only by other point masses, not by vectors.

Saving a data function Loading a data function

Data functions can also be loaded automatically so they are always available just like built-in data columns. To autoload a data function, first create or manually load it into Data Builder, then click the Autoload button on the Data Builder toolbar. Select the functions to autoload in the Autoload Data Functions dialog and click the OK button. The functions will then be autoloaded by all tracks of the same type. Note: data functions are associated with a specific track type and cannot be autoloaded into other track types--e.g., a function selected for autoloading by Point Mass tracks will not be autoloaded by vectors.

Autoloading a data function

12. Analyzing data with Data Tool

Right-click the table and choose Analyze... to open all visible columns in the Data Tool.

Analyze menu item

The Data Tool provides statistical analysis including automatic and manual curve fitting of all or any selected subset of the data. For help using Data Tool, open Data Tool and click its Help button.

Scale dialog