Exercise 4 - Using Other Types of Windows

This exercise teaches you how to use other types of windows, and should take about 15 minutes to complete.

Opening the Sample Simulation

If you already have the Tutorial sample simulation open, choose the File / Revert to Saved menu item, which will return the simulation to the same state that it was in when you first opened it. Otherwise, go through the following steps to open it.

1. If you don't already have AstroGrav running, double-click on the AstroGrav application icon () to start it running.
2. When the Open Simulation file chooser dialog is displayed, navigate to and open the Sample Simulations folder.
3. Select and open the Tutorial.ast file in the English folder.

The Tutorial sample simulation will then open, and you will see the simulation's three windows displayed on your screen.

Using Tree Windows

Tree windows let you view a simulation in the form of a tree showing the hierarchical structure of the system. Go through the following steps to learn how to use a tree window.

1. Click on the Tutorial: Tree window to bring it to the front.
2. Notice how this window displays the Sun on the top row, and each of the nine planets on the following rows. The number displayed in brackets to the right of some of the object names shows the number of 'children' that the object has.
3. Experiment with clicking on the 'expand' and 'collapse' icons to the left of the objects with 'children', to see how you can display as much or as little of the object hierarchy as you desire.
4. Click on the Earth's name, and notice how it highlights to indicate that you have selected the Earth. You need to do this in order to view the Earth's details in the next section.

Using Detail Windows

Detail windows let you view a simulation by showing all the details of a single object, including its relationship with the other objects in the system. Go through the following steps to learn how to use a detail window.

1. Check that the Earth is selected in the frontmost window.
2. Choose the Window / New Detail menu item (or the tool), and check that this has opened a new window titled Tutorial: Earth. This window has a main area showing all of the Earth's data elements, a tree showing the Earth's family at the top right, and a tree showing what the Earth's is orbiting at the bottom right. The two trees can be manipulated in exactly that same way that the trees in tree windows are manipulated.
3. Look at the top-left box in the main area. This shows the Earth's Physical Elements, which are the physical properties that do not vary with the passage of time.
4. Look at the middle-left box in the main area. This shows the Earth's Absolute Elements, which are the position and velocity components relative to the origin of the coordinate frame.
5. Look at the bottom-left box in the main area. This shows the Earth's Orbital Elements, which describe the size, shape, and orientation of the Earth's orbit, together with the position of the Earth on its orbit.
6. Look at the top-right box in the main area. This shows the Earth's Structure Elements, which are the properties of the Earth relative to its parent.
7. Look at the middle-right box in the main area. This shows the Earth's Rectangular Elements, which are the position and velocity components relative to the Earth's parent.
8. Look at the bottom-right box in the main area. This shows the Earth's Other Elements, which are miscellaneous values that each provide a possible alternative to one of the Earth's orbital elements.

You can find much more information when you need to, in the section on Data Elements.

Using Table Windows

Table windows let you view a simulation in the form of a table, with each object's data occupying one row of the table. Go through the following steps to learn how to use a table window.

1. Click on the Tutorial: Table window to bring it to the front.
2. Run the mouse pointer along the column headers, and read the column details that pop up to tell you what each column shows. You may recognise these column headers as being identical to the Physical Elements and Orbital Elements on a detail window.
3. Run the mouse pointer down the row numbers, and read the row details that pop up to tell you the name of the object in each row. This is useful in cases where you have horizontally scrolled a table so that the 'Name' column is no longer visible.
4. Run the mouse pointer around the table cells, and notice how cell details pop up to show you more accurate information about the cell contents.
5. Notice how the Name column has a darker background to indicate that the rows are sorted by name.
6. Click on the Radius column header, and notice how the rows are now sorted by radius.
7. Click on the Radius column header a second time, and notice how the sort order has now changed from ascending to descending.
8. Click on the Radius column header a third time, and notice how the sort order has now changed back to ascending.
9. Experiment with clicking on other column headers to see what effect it has. You can sort the rows any way you want simply by clicking on the appropriate column header.
10. Look at the block of six tools ( , , , , , ), and notice that two of them ( and ) are selected to indicate that the Physical Elements and Orbital Elements are currently displayed.
11. Click on the tool, and notice how the Structure Elements have now appeared between the Physical Elements and the Orbital Elements. A horizontal scroll bar has also appeared that you can move back and forth in order to see all the information.
12. Experiment with the other tools in the block to see what effect they have.
13. Finally, click on some of the cells one at a time, and notice how each time a row highlights to indicate that you have selected an object. You will need to select an object if you want to view or edit its details.

Next: Editing Existing Objects

You've now completed Exercise 4, and are ready to move on to Exercise 5, which teaches you how to edit existing objects.

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