# Linkedin MATLAB Assessment

**Linkedin MATLAB Assessment Answer. In this post you will get Correct Quiz & Assessment Answer Of Linkedin MATLAB Assessment**

## Linkedin MATLAB Assessment

## Offered By ”LinkedIn”

**Q1. From what distribution does the rand() function return value?**

normal

poisson

binomial

**uniform**

**Q2. Based on the code below, c is the \_ of a.**

a = rand(1, 11);

b = sort(a);

c = b(1, ceil(end/2));

**median**

mode

mean

margin

**Q3. What does the Profiler track?**

**execution time**

command history

errors

the value of variables

**Q4. Which code block contains the correct syntax for a while loop?**

[ ]

a = 0;

do

a = a + 1;

while a < 5

end

[ ]

a = 0;

while(a < 5)

a = a + 1;

[ ]

a = 0;

while a < 5:

a = a + 1;

[x]

a = 0;

while a < 5

a = a + 1;

end

**Q5. What does b contain?**

a =

19 20 12 0 6

6 9 56 0 3

46 8 9 8 19

9 8 8 19 46

1 9 46 6 19

[x]

b =

56 0

9 8

[ ]

b =

8 19

19 46

**Q6. You have written a function myfun and want to measure how long it takes to run. Which code segment will return in t the time in seconds it takes myfun to run?**

```
tic;
myfun();
toc;
```

**Q7. What is %% used for?**

argument placeholder

block quotes

**code sections**

conversion specifier

**Q8. what is the . character NOT used for?**

structure field access

a decimal point

**cell array access**

element-wise operations

**Q9. Which function could you use for multiple linear regression?**

polyval

**regress**

solve

polyfit

**Q10. For which of these arrays do mean, median, and mode return the same value?**

**[0 1 1 1 2]**

[1 3 5 5 6]

[0 1 1 1 1]

[0 0 5 5 5]

**Q11. You are in the middle of a long MATLAB session where you have performed many analyses and made many plots. You run the following commands, yet a figure window doesn’t pop up on the top of your screen with your plot. What might be the issue?**

x = [-1:0.1:1];

y = X.^2;

plot(x, y)

Your plot doesn’t plot in a figure window because figure was not called immediately in advance.

Your plot syntax is incorrect.

**Your plot is in a figure window that was already open, hidden behind other windows on your screen.**

Your plot was saved to an image file but not displayed.

**Q12. How do you access the value for the field name in structure S?**

S[‘name’]

**S.name**

S(‘name’)

S{‘name’}

**Q13. What built-in definition does i have?**

basic imaginary unit

**index function**

infinity

index variable

**Q14. Which statement is equivalent to this for loop?**

a = [1 2 3; 4 5 6];

b = zeros(size(a));

for i_row = 1:size(a, 1)

for i_col = 1:size(a, 2)

b(i_row, i_col) = a(i_row, i_col)^2;

end

end

b = a*a;

**b = a.^2;**

b = a^2;

b = pow2(a);

**Q15. You have plotted values of cosine from -10 to 10 and want to change the x-axis tick marks to every pi, from -3pi to 3pi. Which statement will do that?**

xticks(-3pi:3.14:3pi)

**xticks(-3pi:pi:3pi)**

xticks(linespace(-3pi(), 3pi(), pi()))

xticks(linespace(-3pi, 3pi, pi)

**Q16. What is the value of c?**

a = ones(1,3);

b = 1:3;

c = conv(a,b)

[-1 2 -1]

**[1 3 6 5 3]**

6

[1 -2 1]

**Q17. Which function CANNOT be used to randomly sample data?**

datasample

randi

**resample**

randperm

**Q18. Which choice is correct syntax for a switch statement?**

```
x = 7;
switch x
case 2
disp("two");
otherwise
disp("not two");
end
```

[ ]

x = 7;

switch x :

case 2

disp(“two”);

otherwise

disp(“not two”);

end

[ ]

x = 7;

switch x

case 2

disp(“two”);

else

disp(“not two”);

end

[ ]

x = 7;

switch x

case 2

disp(“two”);

default

disp(“not two”);

end

**Q19. What is the result of this code?**

a = 1;

b = 2;

c = 3;

d = 4;

e = c / (~a – b == c – d);

```
c =
NaN
```

**Q20. What is true of a handle class object?**

When you pass a handle object to a function, a new object is made that is independent of the original.

**All copies of handle objects refer to the same underlying object.**

Handle object cannot reference one another.

Handle object do not have a default eq function.

**Q21. Which choice has a different final result in f10 than the other three?**

**f10 = 1;
i = 1;
while i <= 10
i = i + 1;
f10 = i * f10;
end**

**Q22. Which choice will NOT give you a 5 x 5 identity matrix?**

[ ]

a = rand(5);

round(a * inv(a))

diag(ones(5, 1))

**identity(5)**

eye(5)

**Q23. Which statement creates this structure?**

dog =

```
dog.name = 'Bindy';
dog.breed = 'border collie';
dog.weight = 32;
```

**Q24. my_func is a function as follows. What is the value of a at the end of the code beneath?**

function a = my_func(a)

a = a + 1;

end

——————

a = 0;

for i = 1:3

my_func(a);

end

a = my_func(a);

4

3

0

**1**

**Q25. Which statement could create this cell array?**

c =

{[“hello world”]} {1×1 cell} {[“goodbye”]} {1×3 double}

c = {“hello world” {“hello”} “goodbye” [1 2 ]};

c = {“hello world” {“hello”} “goodbye” {[1 2 3]}};

**c = {“hello world” {“hello”} “goodbye” [1 2 3]};**

c = {“hello world” {“hello” “hello”} “goodbye” {[1 2 3]}};

**Q26. Which choice adds b to each row of a?**

a = ones(4, 4);

b= [1 2 3 4];

a = a + reshape(b, 4, 1);

a = a + b’;

**a = a + repmat(b, 4, 1);**

a = a + [b b b b];

**Q27. Which choice replaces all as with os?**

```
for i = 1:length(fruit)
fruit{i}(fruit{i} == 'a') == 'o';
end
```

**Q28. Which statement returns the roots for the polynomial x^2 + 2x – 4?**

poly([1 2 -4])

solve(x^2 + 2x – 4 == 0)

polyfit(x^2 + 2x – 4 == 0)

**roots([1 2 -4])**

**Q29. Which choice is the proper syntax to append a new elements a to the end of 1x 2 dimensional cell array C?**

C = {C a};

C = cellcat(C a)

C = cat(2, {a}, C)

**C{end+1}=a**

**Q30. You have loaded a dataset of people’s heights into a 100 x 1 array called height. Which statement will return a 100 x 1 array, sim_height, with values from a normal distribution with the same mean and variance as your height data?**

sim_height = std(height) + mean(height) * randn(100, 1);

**sim_height = mean(height) + std(height) * randn(100, 1);**

sim_height = randn(std(height), mean(height), [100, 1]);

sim_height = randn(mean(height), std(height), [100, 1]);

**Q31. Which statement returns a cell array of the strings containing ‘burger’ from menu?**

**menu = {‘hot dog’ ‘corn dog’ ‘regular burger’ ‘cheeseburger’ ‘veggie burger’}**

menu{strfind(menu, ‘burger’)}

menu(strfind(menu, ‘burger’))

menu{contains(menu, ‘burger’)}

**menu(contains(menu, ‘burger’))**

**Q32. What is the set of possible values that a may contain?**

a = randi(10, [1, 10]);

a(3) = 11;

a(a>2) = 12;

3, 4, 5, 6, 7, 8, 9, 10, 11, 12

**1, 2, 12**

2, 11, 12

1, 12

**Q33. Which statement is true about the sparse matrices?**

You can use the sparse function to remove empty cells from cell array variables.

**Sparse matrices always use less memory than their associated full matrices.**

Mixtures of sparse and full matrices can be combined in all of MATLAB’s built-in arithmetic operations.

The sparse function requires its input to be a full matrix with at least 50% zero elements.

**Q34. Which statement using logical indices will result in an error?**

a = 1:10;

b = a(a ~= 11)

b = a(a == 1)

**b = a(a>6 && a<9)**

b = a(a | 1)

**Q35. Which statement turns menu into the variable menu_string below?**

**menu = {‘hot dog’ ‘corn dog’ ‘regular burger’ ‘cheeseburger’ ‘veggie burger’}**

menu_string =

‘hot dog

corn dog

regular burger

cheeseburger

veggie burger’

**menu_string = cell2mat(join(menu, newline))**

menu_string = cell2mat(join(menu, ‘\n’))

menu_string = join(menu, newline)

menu_string = cell2mat(pad(menu))

**Q36. Which code snippet sets a new random seed based on the current time and saves the current settings of the random number generator?**

**rng_settings_curr = rng(‘shuffle’);**

[ ]

rng(time());

rng_settings_curr = rng();

rng_settings_curr = rand(‘shuffle’);

[ ]

rng(‘shuffle’);

rng_settings_curr = rng();

**Q37. You have a matrix data in which each column is mono audio recording from a room in your house. You’ve noticed that each column has a very different mean and when you plot them all on the same graph, the spread across the y axis make it impossible to see anything. You want to subtract the mean from each column. Which code block will accomplish this?**

data_nomean = data – repmat(median(data), size(data, 1), 1);

**data_nomean = bsxfun(@minus, data, mean(data));**

[ ]

data_nomean = zeros(size(data));

for i = 1:size(data, 1)

data_nomean(i, 🙂 = data(i, 🙂 – mean(data(i, :));

end

data_nomean = zscore(data’);

**Q38. Which code block results in an array b containing the mean values of each array within C?**

[ ]

b = zeros(1, size(C, 2));

for i_C = 1:size(C, 2)

b(i_C) = mean(C(i_C));

end

b = cellfun(@mean, C);

[ ]

b = zeros(1, size(C, 1));

for i_C = 1:size(C, 1)

b(i_C) = mean(C{i_C}(:));

end

**b = cellfun(@(m) mean(m(:)), C)**

**Q39. Which statement creates a logical array that is 1 if the element in passwords contains a digit and 0 if it does not?**

**passwords = {‘abcd’ ‘1234’ ‘qwerty’ ‘love1’};**

contains(password, ‘\d’)

~isempty(regexp(passwords, ‘\d’))

**cellfun(@(x) ~isempty(regexp(x, ‘\d’)), passwords)**

regexp(passwords, ‘\d’)

**Q40. Which is NOT a function that adds text to a plot?**

title

text

**label**

legend

**Q41. Which code block most likely produced this graph?**

MatLab Q39

[ ]

figure

x = rand(10,10);

r = corrcoef(x);

surf(r)

colorbar

[x]

figure

x = rand(10,10);

r = corrcoef(x);

imagesc(r)

colorbar

**Q42. What kind of files are stored with the .mat extension?**

figure files

script files

function files

**stored variable files**

**Q43. You would like to randomly reorder every element in array a and put the result into another array b. Which code is NOT necessary to do that?**

a = 1:10;

**b = a(randi(10, 1, 10));**

[ ]

m = perms(a);

i = randi(factorial(10), 1);

b = a(m(i, :))

[ ]

[s, j] = sort(rand(10, 1));

b = a(i);

[ ]

b = a(randperm(10));

**Q44. Which statement returns 1 (true)?**

a = ‘stand’

b = “stand”

**a == b**

ischar(b)

length(a) == length(b)

class(a) == class(b)

**Q45. Which does E contain?**

C = {‘dog’ ‘cat’ ‘mouse’}

D = {‘cow’ ‘piranha’ ‘mouse’}

E = setdiff(C,D)

**E = {‘cat’} {‘dog’}**

E = {‘mouse’}

E = {‘cat’} {‘cow’} {‘dog’} {‘piranha’}

E =

**Q46. Where in the UI can you see what variables have been created, their values, and their class?**

Editor

command window

details

**workspace**

**Q47. Given the following x and y coordinates, which choice calculates a linear regression for the x and y coordinates, and which plots the points of the x,y data and the regression line on the same graph?**

x = 9.0646 6.4362 7.8266 8.3945 5.6135 4.8186 2.8862 10.9311 1.1908 3.2586

y = 15.4357 11.0923 14.1417 14.9506 8.7687 8.0416 5.1662 20.5005 1.0978

[x]

coeff_line = polyfit(x,y,1)

x_line = floor(min(x)):0.1:ceil(max(x));

y_line = polyval(coeff_line,x_line)

figure; plot(x,y,’o’)

hold on

plot(x_linemy_line)

[ ]

figure

plot(x,y,’o’)

coeff_line = polyfit(x,y,1);

x_line = floor(min(x)):0.1:ceil(max(x));

y_line = polyval(coeff_line,x_line);

plot(x_line,y_line)

[ ]

figure

plot(x,y)

coeff_line = polyfit(x,y,1);

x_line = floor(min(x)):0.1:ceil(max(x));

y_line = polyval(coeff_line,x_line);

hold on; plot(x_line,y_line)

[ ]

coeff_line = polyfit(x,y,1);

x_line = floor(min(x)):0.1:ceil(max(x));

y_line = polyval(coeff_line,x_line);

figure; plot(x,y,’o’)

hold on

plot(x_line,y_line)

**Q48. If you run this piece of code, you will get an error. Why?**

a = [0 1 2 3; 4 5 6 7];

a = a^2;

**You are attempting to multiply a non-square matrix by itself, causing a dimension mismatch.**

MATLAB does not allow you to square all the elements in the matrix in a single operation.

You must use the ** operator instead of the ^ operator.

You cannot square matrices that have a 0 as the first element.