Built-in Functions

Question 0

help [insert word here]

Answer 0

Explains word.

Ex. Help, format, elfun, etc.

Question 1

Demo

Answer 1

Shows MATLAB examples in help window

Question 2

doc

Answer 2

Shows documentation page in help window

Question 3

Quit

Exit

Answer 3

Close MATLAB

Question 4

namelengthmax

Answer 4

63

Question 5

who

Answer 5

Shows variables in command window

Question 6

whos

Answer 6

Shows variables and information in command window

Question 7

clear

Answer 7

Deletes variables

Question 8

intmin (‘int8’)

intmax (‘int8’)

Answer 8

-128

127

Question 9

intmin (‘int16’)

intmax (‘int16’)

Answer 9

Help!

Question 10

intmin (‘int32’)

intmax (‘int32’)

Answer 10

Help!

Question 11

format short

Answer 11

Answer in four decimal places

Question 12

format long

Answer 12

Answer in 15 decimal places

Question 13

Format loose

Answer 13

Double spaced

Question 14

Format compact

Answer 14

Single spaced

Question 15

fix (x)

Answer 15

Rounds towards zero

Question 16

floor (x)

Answer 16

Rounds towards negative infinity

Question 17

ceil

Answer 17

Rounds toward positive infinity

Question 18

rem (x, y)

Answer 18

Returns remainder of x/y

Question 19

mod (x, y)

Answer 19

Returns remainder of x/y. Mod (x, 0) returns x.

Question 20

Sign (x)

Answer 20

Returns 1 or -1 depending on sign of x.

Question 21

nthroot (x, y)

Answer 21

Returns the y- root of x.

Question 22

exp (n)

Answer 22

Returns e^n

Question 23

rand

Answer 23

Returns random number between 0 and 1

Question 24

rng (‘shuffle’)

Answer 24

Sets seed to clock time

Question 25

rng (‘intseed’)

Answer 25

Sets seed to an integer

Question 26

rng (‘default’)

Answer 26

Sets seed to default number determined by MATLAB startup.

Question 27

rand*10

Answer 27

Random number between 0 and 10

Question 28

rand *(high - low) + low

Answer 28

Generates a random number between high and low.

Question 29

round (rand)

Answer 29

Rounds the random real number produced by rand to an integer.

Question 30

randi ([intmin, intmax])

Answer 30

Generates random integer between intmin and intmax.

Question 31

length (vec)

Answer 31

Returns number of elements in vector.

Question 32

length (mat)

Answer 32

Returns number of rows or columns, whichever is larger

Question 33

size (vec)

size (mat)

Answer 33

Returns the number of rows and columns

Hint:
[r c] = size (mat)

Question 34

numel (vec)

numel (mat)

Answer 34

Returns number of elements.

Question 35

fliplr (mat)
flipud (mat)
rot90 (mat)
reshape (mat)

Answer 35

Ways to alter a matrix

Question 36

vec = [ ]

Answer 36

Creates an empty vector

Question 37

vec (x) = [ ]

Answer 37

Deletes the x-th element

Note: individual elements cannot be removed from matrices. Must remove an entire roe or column.
mat ( : , x) = [ ]

Question 38

diff(vec)

Answer 38

Returns the difference between elements in vec. Length will be 1 less than length of vec.