In Plot view you can directly draw objects on the screen using various drawing tools.
For example, For example, to draw a circle, tap
and select Circle. Now tap where you want the center of the circle to be and
press E. Next, tap a point that is to be on the circumference and press E. A circle is drawn with a center at the location of your first tap, and with a radius equal to the distance between your first tap and second tap.
Creating or selecting an object always involves at least two steps: tap and press E. Only by pressing E do you confirm your intention to create the point or select an object. When creating a point, you can tap on the screen and then use the cursor keys to accurately position the point before pressing E.
Note that there are on-screen instructions to help you. For example, Hit Center means tap where you want the center
of your object to be, and Hit Point 1 means tap at the location of the first point you want to add.
You can draw any number of geometric objects in Plot view.
See “Geometric objects” on page 141 for a list of the objects you can draw. The drawing tool you choose—line, circle, hexagon, etc.—remains selected until you deselect it. This enables you to quickly draw a number of objects of the same type (such as a number of hexagons). Once you have finished drawing objects of a particular type, deselect the drawing tool by press J. (You can tell if a drawing tool is still active by the presence of on-screen help at the top left-side corner of the screen, help such as Hit Point 1.)
An object in Plot view can be manipulated in numerous ways, and its mathematical properties can be easily determined (see page 138).
Object naming Each geometric object you create is given a name. In the example shown on page 129, note that the circle has been named C. Each defining point is also been named: the center point has been named A, and the point tapped to set the radius of the circle has been named B.
It is not only the points that define a geometric object that are given a name. Every component of the object that has any geometric
significance is also named.
If, for example, you create a hexagon, the hexagon is
given a name as is each point at each vertex. In the example at the right, the pentagon is named C, the points used to define the hexagon are named A and B, and the remaining four vertices are named D, E, G, and H. Moreover, each of the six segments is also given a name: I, J, K, L, M, and N.
These names are not displayed in Plot view, but you can see them if you go to Symbolic view (see “Symbolic view in detail”
on page 136).
Naming objects and parts of objects enables you to refer to them in calculations. This is explained in “Numeric view in detail” on page 138.
You can rename an object. See “Renaming an object” on page 137.
Selecting an
object To select an object, just tap on it. The color of a selected item changes to cyan.
To select a point in Plot view, just press E. A list of all the points appears. Select the one you want.
Hiding names You can choose to hide the name of an object in Plot view:
1. Press Z.
2. Select Toggle Caption.
The Select Object menu appears.
3. Select the object whose label (that is, caption) you want to hide.
4. Press J.
Redisplay a hidden name by repeating this procedure.
Moving objects Points To move a point press E. A list of all the points appears. Select the one you want to move, then tap on the new location for it, and press E. You can also press the arrow keys to move a selected point. A point can be selected directly by tapping on it. (If the bottom-right of the screen shows the name of the point, you have accurately tapped the point; otherwise the pointer coordinates are shown, indicating that the point is not selected.)
Composite objects To move a multi-point object, see
“Translation” on page 148.
Coloring objects An object is colored black by default (and cyan when it is selected). If you want to change the color of an object:
1. Press Z.
2. Select Change Color.
The Select Object menu appears.
3. Select the object whose color you want to change.
The Choose Color palette appears.
4. Select the color you want.
5. Press J.
Note that for object with closed contours (such as a circle or polygon) it is the fill color that is changed.
Filling objects An object with closed contours (such as a circle or polygon) can be filled with color.
1. Press Z.
2. Select Fill with Color.
The Select Object menu appears.
3. Select the object you want to fill.
The object is highlighted.
1. Press Z.
2. Select Change Color.
The Choose Color palette appears.
3. Select the color you want.
4. Press J.
Removing fill To remove the fill from an object:
1. Press Z.
2. Select Fill with Color.
The Select Object menu appears.
3. Select the object.
Undoing You can undo your last addition or change to Plot view by pressing t. However, you must have keyboard shortcuts activated for this to work. See page 135.
Clearing an
object To clear one object, select it and tap C. Note that an object is distinct from the points you entered to create it. Thus deleting the object does not delete the points that define it.
Those points remain in the app. For example, if you select a circle and press C, the circle is deleted but the center point and radius point remain.
If you tap C when no object is selected, a list of objects appears. Tap on the one you want to delete, and tap to confirm your intention. If you don’t want to delete an object, press J to close the list.
Note that points you add to an object once the object has been defined are cleared when you clear the object. Thus if you place a point (say D) on a circle and delete the circle, the circle and D are deleted, but the defining points—the center and radius points—remain.
Clearing all
objects To clear the app of all geometric objects, press SJ. You will be asked to confirm your intention to do so. Tap to clear the app, or to keep the app as it is, Moving about
the Plot view You can pan by dragging a finger across the screen: either up, down, left, or right. You can also use the cursor keys to pan once the cursor is at the edge of the screen.
Zooming You can zoom using touch gestures (see page 3) or by tapping and choosing a zoom option. The zoom options are the same as you find in the Plot view of many apps in the calculator (see “Zoom” on page 78).