How To Get Command Window In Matlab

Hi friends! I hope you all had a great start to the new year's day.

In our first lecture, we had looked at the MATLAB prompt and also learned how to enter a few bones commands that utilise math operations. This too allowed u.s. to use the MATLAB prompt every bit an advanced calculator. Today we will look at the various MATLAB keywords, and a few more than bones commands and MATLAB functions, that will help us keep the prompt window organized and help in mathematical calculations. We are also going to get familiar with MATLAB's interface and the various windows. We will likewise write our commencement user-defined MATLAB functions.

MATLAB keywords and functions

Like any programming language, MATLAB has its own fix of keywords that are the bones building blocks of MATLAB. These 20 edifice blocks tin can be called by simply typing 'iskeyword' in the MATLAB prompt.

The list of 21 MATLAB keywords obtained every bit a result of running this command is every bit follows:

• 'break'
• 'case'
• 'catch'
• 'classdef'
• 'continue'
• 'else'
• 'elseif'
• 'end'
• 'for'
• 'function'
• 'global'
• 'if'
• 'otherwise'
• 'parfor'
• 'persistent'
• 'return'
• 'spmd'
• 'switch'
• 'try'
• 'while'

To test if the give-and-take while is a MATLAB keyword, we run the command

iskeyword('while')

The output 'one' is saying that the result is 'Truthful', and therefore, 'while' is indeed a keyword.

'logical' in the output refers to the fact that this output is a datatype of the type 'logical'. Other data types include 'uint8', 'char' then on and we will study these in more particular in the next lecture.

Autonomously from the basic arithmetics functions, MATLAB also supports relational operators, represented by symbols and the corresponding functions which look as follows:

Here, we create a variable 'a' which stores the value 1. The various comparison operators inside MATLAB used here, volition give an output 'ane' or '0' which will mean 'True' or 'False' with respect to a particular statement.

Autonomously from these basic building blocks, MATLAB engineers have fabricated available, a huge library of functions for various advanced purposes, that take been written using the basic MATLAB keywords merely.

We had seen previously that the double arrowed ('>>') MATLAB prompt is always willing to accept command inputs from the user. Find the '' to the left of the MATLAB prompt, with a downwardly facing arrow. Clicking this downward facing pointer allows us to access the various in-congenital MATLAB functions including the functions from the various installed toolboxes. You lot can admission the entire list of in-built MATLAB functions, including the trigonometric functions or the exponents, logarithms, etc.

Here are a few commands that we recommend you to try that make use of these functions:

A = [1,ii,3,iv];

B = sin(A);

10 = 1:0.ane:10;

Y = linspace(i,ten,100);

clc

clear all

quit

Discover that while creating a matrix of numbers, nosotros e'er use the square braces '[]' as in the commencement line, whereas, the input to a part is ever given with circular brace '()' every bit in the second line.

We can too create an ordered matrix of numbers separated past a stock-still deviation past using the syntax first:increase:end, as in the third command.

Alternatively, if we need to have exactly 100 equally separated numbers betwixt a offset and and end value, we can use the 'linspace' control.

Finally, whatever results accept been output by the MATLAB response in the control window can be erased past using the 'clc' command which stands for 'articulate panel', and all the previously stored MATLAB variables tin be erased with the 'clear all' command.

To go out MATLAB directly from the prompt, you can utilise the 'quit' command.

In the adjacent section, permit us become ourselves familiarized with the MATLAB environment.

The MATLAB Interface Surroundings

A typical MATLAB work surround looks as follows. Nosotros volition discuss the diverse windows in particular:

When you open MATLAB on your desktop, the following superlative carte is visible. Clicking on 'new' allows us to enter the editor window and write our own programs.

You can besides run code section by department past using the '%%' command. For beginners, I'd say that this feature is actually really useful when you're trying to optimize parameters.

Card Bar and the Tool Bar

On the top, nosotros have the menu bar and the toolbar. This is followed by the accost of the current directory that the user is working in.

By clicking on 'New' option, the user tin can choose to generate a new script, or a new alive script, details of which we will encounter in the side by side department.

Current Folder

Nether the Electric current Folder window, you will see all the files that be in your current directory. If you select whatever item file, you lot tin can likewise see information technology details in the bottom panel equally shown beneath.

Editor Window

The Editor Window will appear when you lot open a MATLAB file with the extension '.m' from the current binder past double clicking it, or when yous select the 'New Script' selection from the toolbar. Yous can fifty-fifty define variables like yous do in your linear algebra class.

The code in the editor tin also be split into various sections using the '%%' command. Think that a unmarried '%' symbol is used to create a comment in the Editor Window.

Workspace Window

Remember that the semicolon ';' serves to suppress the output. Whenever you lot create new variables, the workspace will start showing all these variables. As nosotros tin encounter, the variables named 'a', 'b', 'c', and 'x', 'y', 'z'. For each variable, nosotros take a detail size, and a type of variable, which is represented past the 'Course'. Here, the 'Course' is double for uncomplicated numbers.

You lot tin can directly right click and salve whatever variable, straight from this workspace, and information technology volition exist saved in the '.mat' format in the current folder.

Alive Editor Window

If still, you open a '.mlx' file from the current folder, or select the pick to create a 'New Alive Script' from the toolbar, the Live Editor window wil open instead.

With the Alive Script, you tin get started with the symbolic manipulation, or write text into the MATLAB file as well. Live scripts can also do symbolic algebraic calculation in MATLAB.

For example, in the figure below, we define symbol x with the command

syms x

We click 'Run' from the toolbar to execute this file.

The Live Editor as well allows u.s.a. to toggle between the text and the code, right from the toolbar. Later on that, the various code sections tin exist run using the 'Run' pick from the toolbar and the rendered output can exist seen inside the Alive Editor.

Command History

Finally, there is the command history window, which will store all the previous commands that were entered on any previous date in your MATLAB environment.

Effigy window

Whenever you generate a plot, the figure window will announced which is an interactive window with it's ain toolbar, to interact with the plots.

We apply the following commands to generate a plot, and you can attempt it too:

X = 1:0.1:ii*pi;

Y = sin(X)

plot(X,Y)

The magnifier tools help u.s.a. to zoom into and out of the plot while the '=' tool helps u.s. to discover the x and y value of the plot at any particular point.

Also detect that now, the size of the '10' and 'Y' variables is different, because we actually generated a matrix instead of assigning a single number to the variable.

Creating a New User-Defined Function

By selecting New Function from the toolbar, yous tin also create a new user-divers function and save it equally an m-file. The name of this m-file is supposed to be the same as the name of the function. The post-obit template gets opened when you select the selection to create a new user-defined role:

The syntax function is used to brand MATLAB know that what we are writing is a part filee. Again notice that the inputs to the office, inputArg1 and inputArg2, are inside the round braces. The multiple outputs are surrounded past square braces because these can be a matrix. We will create a sample function SumAndDiff using this template, that will output the sum and departure of whatever two numbers. The part file SumAndDiff.yard looks as follows:

Once this function is saved in the current binder, it can be recognized by a current MATLAB script or the MATLAB command window and used.

Exercises:

1. Create a list of numbers from 0 to 1024, with an increment of 2.
2. Find the exponents of ii from 0^th to 1024^th exponent using results of the previous exercise.
3. What is the length of this matrix?
4. Plot the output, and modify the y centrality scale from linear to log, using the following command afterwards using the plot function: gear up(gca, 'yscale', 'log')
5. Let us go ahead now and import an image into MATLAB to show yous what the image looks similar in the class of matrices. Y'all demand to take the image processing toolbox installed in gild for the image functions to work.

Run the post-obit control in the MATLAB prompt:

I = imread('ngc6543a.jpg');

This calls the image titled 'ngc6543a.jpg' which is stored inside MATLAB itself for case purposes. Detect the size of this image variable I in the workspace. You will interestingly discover this to be a 3D matrix. Likewise notation the form of this variable.

In the side by side tutorial, nosotros will deep swoop into the MATLAB information types, the format of press these data types and write our first loops inside MATLAB.

Source: https://www.theengineeringprojects.com/2022/02/introduction-to-matlab-command-window.html

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