MatLab Basics

Question 1

what are the Two Main Windows in Matlab?

Answer 1

1. Command Window
2. Editor Window

Question 2

Uses of Command Window in MatLab

Answer 2

Useful for testing, immediate output

Question 3

Uses of Editor Window in Matlab

Answer 3

-Word Processing environment
-Multiple lines of code
-Can be saved and exectued

Question 4

what are M files, what do they contain?

Answer 4

Matlab Script File
-series of commands
-can be main program or function
-.m file extension

Question 5

Function

Answer 5

Executable process
-Can’t be executed independently
-must be called by a statement
-data is passed to a function
-output is passed back to calling program

Question 6

Program

Answer 6

Executes a series of commands or functions
-all variables created in a program are considered global variables
-can be executed independantly
-can be executed in another program

Question 7

Green Text

Answer 7

Comments
-preceded by a %
-not included in operation

Question 8

Hierarchy of functions

Answer 8

Main Program -> function -> (sub) function

Question 9

Variable Naming Protocol

Answer 9

Rule 1: Must consist of only letters a-z, digits 0-9 and underscore
Rule 2: Must start with a letter
Notes:
-up to 31 characters
-case sensitive

Question 10

Numeric Variable

Answer 10

contains only numbers

Question 11

String Variable

Answer 11

contains numbers and letters

Question 12

Basic Arithmetic Functions in MatLab

Answer 12

Addition +
Minus -
Multiply element by element .*
Divide element by element ./
Matrix Multiply *
Matrix Right Divide /

Question 13

Element by element math

Answer 13

-Most functions will not use matrix math
-item to item comparison
-Arrays must be of equal dimensions

Question 14

Where are Relational Operators used?

Answer 14

Used in loops and if statements

Question 15

Comparative Relational Operators

Answer 15

equal
not equal
less than
greater than
less than or equal
greater than or equal

Question 16

Logical Relational Operators and their calling convention

Answer 16

AND &
OR |
NOT ~

Question 17

Matrix Indexing

Answer 17

Colon Operator :

Question 18

Calling an entire column

Answer 18

(:,x) all rows in x column

Question 19

Calling an entire row

Answer 19

(x,:) all columns in x row

Question 20

ones

Answer 20

calls an array of 1’s of the specified size
e.g. ones(2,2) = 1 1
1 1

Question 21

Zeroes

Answer 21

calls an array of 0’s of the specified size

Question 22

mean

Answer 22

calls mean of a variable

Question 23

std

Answer 23

calls standard deviation of a variable

Question 24

plot

Answer 24

linear plot (X,Y)
plots x vs Y

Question 25

subplot

Answer 25

creates axes in tiled positions

Question 26

ezplot

Answer 26

not a recommended function
plots function over default domain

Question 27

sin,cos,tan

Answer 27

Sine, Cosine and Tangent
Conversely:
asin,acos,atan

Question 28

clear

Answer 28

clear variables and functions from memory (workspace)

Question 29

clc

Answer 29

clear command window

Question 30

close

Answer 30

close figure or specified window

Question 31

close all

Answer 31

closes all windows and Matlab

Question 32

==

Answer 32

equal

Question 33

~=

Answer 33

not equal

Question 34

<

Answer 34

less than

Question 35

>

Answer 35

greater than

Question 36

<=

Answer 36

less than or equal

Question 37

> =

Answer 37

greater or equal