Scripts

To create a script, use theeditcommand,

editmysphere

This command opens a blank file namedmysphere.m. Enter some code that creates a unit sphere, doubles the radius, and plots the results:

[x,y,z] = sphere; r = 2; surf(x*r,y*r,z*r) axisequal

Next, add code that calculates the surface area and volume of a sphere:

A = 4*pi*r^2; V = (4/3)*pi*r^3;

Whenever you write code, it is a good practice to add comments that describe the code. Comments enable others to understand your code and can refresh your memory when you return to it later. Add comments using the percent (%) symbol.

% Create and plot a sphere with radius r.[x,y,z] = sphere;% Create a unit sphere.r = 2; surf(x*r,y*r,z*r)% Adjust each dimension and plot.axisequal% Use the same scale for each axis.% Find the surface area and volume.A = 4*pi*r^2; V = (4/3)*pi*r^3;

Save the file in the current folder. To run the script, type its name at the command line:

mysphere

You can also run scripts from the Editor using theRunbutton,.

Live Scripts

而不是writing code and comments in plain text, you can use formatting options inlive scriptsto enhance your code. Live scripts allow you to view and interact with both code and output and can include formatted text, equations, and images.

For example, convertmysphereto a live script by selectingSave Asand changing the file type to a MATLAB live code file (*.mlx). Then, replace the code comments with formatted text. For instance:

To create a new live script using theeditcommand, include the.mlxextension with the file name:

editnewfile.mlx

Loops and Conditional Statements

在任何年代cript, you can define sections of code that either repeat in a loop or conditionally execute. Loops use afororwhilekeyword, and conditional statements useiforswitch.

Loops are useful for creating sequences. For example, create a script namedfibseqthat uses aforloop to calculate the first 100 numbers of the Fibonacci sequence. In this sequence, the first two numbers are 1, and each subsequent number is the sum of the previous two,F_n=F_n-1+F_n-2.

N = 100; f(1) = 1; f(2) = 1;forn = 3:N f(n) = f(n-1) + f(n-2);endf(1:10)

When you run the script, theforstatement defines a counter namednthat starts at 3. Then, the loop repeatedly assigns tof(n), incrementingnon each execution until it reaches 100. The last command in the script,f(1:10), displays the first 10 elements off.

ans = 1 1 2 3 5 8 13 21 34 55

Conditional statements execute only when given expressions are true. For example, assign a value to a variable depending on the size of a random number:'low','medium', or'high'. In this case, the random number is an integer between 1 and 100.

num = randi(100)ifnum < 34 sz ='low'elseifnum < 67 sz ='medium'elsesz ='high'end

The statementsz = 'high'only executes whennumis greater than or equal to 67.

Script Locations

MATLAB looks for scripts and other files in certain places. To run a script, the file must be in the current folder or in a folder on thesearch path.

By default, theMATLABfolder that the MATLAB Installer creates is on the search path. If you want to store and run programs in another folder, add it to the search path. Select the folder in the Current Folder browser, right-click, and then selectAdd to Path.