View angle control in MATLAB - Step-by-Step Execution

Concept Flow - View angle control

Start

↓

Create 3D plot

↓

Set initial view angle

↓

User changes view angle

↓

Update plot view

↓

Display updated plot

↓

End

This flow shows how a 3D plot is created, an initial view angle is set, and then the view angle is updated to control how the plot is seen.

Execution Sample

MATLAB

x = peaks;
figure;
surf(x);
view(45,30);

This code creates a 3D surface plot of the 'peaks' function and sets the view angle to azimuth 45 degrees and elevation 30 degrees.

Execution Table

Step	Action	Variable/Function	Value/Effect	Plot View Angle
1	Generate data	x = peaks	Matrix of size 49x49	Default
2	Open figure window	figure	New figure created	Default
3	Create surface plot	surf(x)	3D surface plotted	Default
4	Set view angle	view(45,30)	Azimuth=45°, Elevation=30°	Az=45°, El=30°
5	Display plot	plot shown	Plot visible with set view	Az=45°, El=30°
6	End	-	-	Az=45°, El=30°

💡 View angle set and plot displayed; execution ends.

Variable Tracker

Variable	Start	After Step 1	After Step 3	After Step 4	Final
x	undefined	49x49 matrix	49x49 matrix	49x49 matrix	49x49 matrix
figure	none	figure created	figure created	figure created	figure created
view angle	default	default	default	az=45°, el=30°	az=45°, el=30°

Key Moments - 3 Insights

Why does the plot not change until the 'view' function is called?

Because the plot is created with default view angles first (see Step 3), and only after calling 'view(45,30)' (Step 4) does the viewpoint update.

What do the two numbers in 'view(45,30)' mean?

The first number (45) is the azimuth angle (rotation around vertical axis), and the second (30) is the elevation angle (height angle), as shown in Step 4.

Can the view angle be changed after the plot is displayed?

Yes, calling 'view' again updates the plot's viewpoint dynamically, as the variable_tracker shows the view angle changes after Step 4.

Visual Quiz - 3 Questions

Look at the execution_table at Step 4, what is the azimuth angle set by the 'view' function?

A 45 degrees

B 30 degrees

C Default angle

D 90 degrees

💡 Hint

Check the 'Plot View Angle' column at Step 4 in the execution_table.

According to variable_tracker, what is the size of variable 'x' after Step 1?

A Undefined

B 49x49 matrix

C Scalar value

D Empty matrix

💡 Hint

Look at the 'x' row and 'After Step 1' column in variable_tracker.

If you call 'view(0,90)' after Step 4, what will happen to the plot view angle?

A Plot will close

B Azimuth 45°, Elevation 30° (no change)

C Azimuth 0°, Elevation 90° (top-down view)

D Error because view can only be set once

💡 Hint

Recall from key_moments that 'view' can update the angle anytime; changing to (0,90) means top-down view.

Concept Snapshot

View angle control in MATLAB:
- Use 'view(az, el)' to set azimuth and elevation angles.
- Azimuth rotates around vertical axis.
- Elevation sets height angle.
- Call 'view' after plotting to change perspective.
- Angles in degrees, e.g., view(45,30).

Full Transcript

This example shows how to control the view angle of a 3D plot in MATLAB. First, data is generated using the 'peaks' function. Then a figure window is opened and a surface plot is created. Initially, the plot uses default view angles. By calling 'view(45,30)', the azimuth is set to 45 degrees and elevation to 30 degrees, changing how the plot is seen. The variable tracker shows the data matrix 'x' and the figure remain constant, while the view angle updates. Key moments clarify that the view function changes the perspective only after it is called, and the two numbers represent rotation and height angles. The visual quiz tests understanding of these angles and variable states. This helps beginners see step-by-step how MATLAB controls 3D plot views.