Plot view functionality that is common to many apps is described in detail in this section. Functionality that is available only in a particular app is described in the chapter dedicated to that app.
Press P to open Plot view.
Zoom
[Scope: Advanced Graphing, Function, Parametric, Polar, Sequence, Solve, Statistics 1 Var, and Statistics 2Var. Also, to a limited degree, Geometry.]
Zooming redraws the plot on a larger or smaller scale. It is a shortcut for changing the range settings in Plot Setup view. The extent of most zooms is determined by two zoom factors: a horizontal and a vertical factor. By default, these factors are both 2. Zooming out multiplies the scale by the factor, so that a greater scale distance appears on the screen. Zooming in divides the scale by the factor, so that a shorter scale distance appears on the screen.
Zoom factors To change the default zoom factors:
1. Open the Plot view of the app (P).
2. Tap to open the Plot view menu.
3. Tap to open the Zoom menu.
4. Scroll and select Set Factors.
The Zoom Factors screen appears.
5. Change one or both zoom factors.
6. If you want the plot to be
centered around the current position of the cursor in Plot view, select Recenter.
7. Tap or press E. Zoom
options Zoom options are available from three sources:
• the keyboard
• the menu in Plot view
• the Views menu (V).
Zoom keys There are two zoom keys: pressing + zooms in and pressing w zooms out. The extent of the scaling is determined by the
ZOOMFACTORsettings (explained above).
Zoom menu In Plot view, tap and tap an option. (If is not displayed, tap .) The zoom options are explained in the following table. Examples are provided on “Zoom examples” on page 81.
Option Result
Center on
Cursor Redraws the plot so that the cursor is in the center of the screen. No scaling occurs.
Box Explained in “Box zoom” on page 80.
In Divides the horizontal and vertical scales by X Zoom and Y Zoom (values set with the Set Factors option explained on page 78). For instance, if both zoom factors are 4, then zooming in results in 1/
4 as many units depicted per pixel.
(Shortcut: press +.)
Out Multiplies the horizontal and vertical scales by the X Zoom and Y Zoom settings.
(Shortcut: press w.)
X In Divides the horizontal scale only, using the X Zoom setting.
X Out Multiplies the horizontal scale only, using the X Zoom setting.
Y In Divides the vertical scale only, using the Y Zoom setting.
Y Out Multiplies the vertical scale only, using the Y Zoom setting.
Square Changes the vertical scale to match the horizontal scale. This is useful after you have done a box zoom, X zoom or Y zoom.
Box zoom A box zoom enables you to zoom in on an area of the screen that you specify.
1. With the Plot view menu open, tap and select Box.
2. Tap one corner of the area you want to zoom in on and then tap .
3. Tap the diagonally opposite corner of the area you want to zoom in on and then tap .
The screen fills with the area you specified. To return to the default view, tap and select Decimal.
Views menu The most commonly used zoom options are also available on the Views menu. These are:
• Autoscale
• Decimal
• Integer
• Trig.
Autoscale Rescales the vertical axis so that the display shows a representative piece of the plot given the supplied x axis settings. (For Sequence and Statistics apps, autoscaling rescales both axes.)
The autoscale process uses the first selected function to determine the best scale to use.
Decimal Rescales both axes so each pixel is 0.1 units. This is equivalent to resetting the default values for XRNG and YRNG. Integer Rescales the horizontal axis only, making
each pixel equal to 1 unit.
Trig Rescales the horizontal axis so that 1 pixel equals/24 radians or 7.5 degrees; rescales the vertical axis so that 1 pixel equals 0.1 units.
Undo Zoom Returns the display to the previous zoom, or if there has been only one zoom, displays the graph with the original plot settings.
Option Result (Cont.)
These options—which can be applied whatever view you are currently working in—are explained in the table immediately above. to divide the screen into two halves, with each half showing the plot, and then to apply a zoom only to one side of the screen. The illustration at the right is a plot of y = 3sinx. To split the screen into two halves:
1. Open the Views menu.
Press V
2. Select Split Screen:
Plot Detail.
The result is shown at the right. Any zoom operation you undertake will be
applied only to the copy of the plot in the right-hand half of the screen. This will help you test and then choose an appropriate zoom.
Note that you can replace the original plot on the left with the zoomed plot on the right by tapping .
To un-split the screen, press P. Zoom
examples The following examples show the effects of the zooming options on a plot of using the default zoom factors (2 × 2). Split-screen mode (described above) has been used to help you see the effect of zooming.
Note that there is an Unzoom option on the Zoom menu. Use this to return a plot to its pre-zoom state. If the Zoom menu is not shown, tap .
Zoom In In
Shortcut: press + 3sinx
Zoom Out Out Shortcut: press w
X In X In
X Out X Out
Y In Y In
Y Out Y Out
Square Square
Notice that in this example, the plot on left has had a Y In zoom applied to it. The Square zoom has returned the plot to its default state where the X and Y scales are equal.
Autoscale
Autoscale
Decimal Decimal
Notice that in this example, the plot on left has had a X In zoom applied to it. The Decimal zoom has reset the default values for the x-range and y-range.
Integer
Integer
Trig
Trig
Trace
[Scope: Advanced Graphing, Function, Parametric, Polar, Sequence, Solve, Statistics 1 Var, and Statistics 2Var.]
The tracing functionality enables you to move a cursor (the trace cursor) along the current graph.
You move the trace cursor by pressing < or >. You can also move the trace cursor by tapping on or near the current plot. The trace cursor jumps to the point
on the plot that is closest point to where you tapped.
The current coordinates of the cursor are shown at the bottom of the screen. (If menu buttons are hiding the coordinates, tap
to hide the buttons.)
Trace mode and coordinate display are automatically turned on when a plot is drawn.
To select a
plot If there is more than one plot displayed, press = or \ until the trace cursor is on the plot you are interested in.
To evaluate a
definition One of the primary uses of the trace functionality is to evaluate a plotted definition. Suppose in Symbolic view you have defined F1(X) as (X – 1)2– 3. Suppose further that you want to know what the value of that function is when X is 25.
1. Open Plot view (P).
2. If the menu at the bottom of the screen is not open, tap .
3. If more than one definition is plotted, ensure that the trace cursor is on the plot of the definition you want to evaluate.
You can press to see the definition of a plot, and press = or \ to move the trace cursor from plot to plot.
4. If you pressed to see the definition of a plot, the menu at the bottom of the screen will be closed. Tap to re-open it.
5. Tap .
6. Enter 25 and tap . 7. Tap .
The value of F1(X) when X is 25 us shown at the bottom of the screen. . This is one of many ways the HP Prime provides for you to evaluate a function for a specific independent variable. You can also evaluate a function in
Numeric view (see page 92). Moreover, any expression you define in Symbolic view can be evaluated in Home view. For example, suppose F1(X)is defined as (x– 1)2– 3. If you enter F1(4) in Home view and press E you get 6, since (4– 1)2– 3 = 6.
To turn tracing on or off
• To turn off tracing, tap .
• To turn on tracing, tap .
If these options are not displayed, tap .
When tracing is off, pressing the cursor keys no longer constrains the cursor to a plot.