Some basic MATLAB questions

Given a vector u of dimension 20x1 consisting of random variables from a uniform-

distribution (distributed on [0,1]).

Instructions:

- Create a code in MATLAB,

- that creates the vector u,

- which contains both 'for loops' and 'if loops',

- and specifies for all values in the vector u in which quarter the number lies.

I managed to create the vector and split it into the quarters. I dont get how to implant the for and if loops.

Can someone help me out ? :((

[Torsten]

Unclear.

What are and why "if loops" ?

What do you mean by "quarter" ? You mean if the numbers lie in [0:0.25],(0.25:0.5],(0.5:0.75] or (0.75:1] ?

[JACK]

Yes exacly, i can't figure out how to manage to get the numbers into those quarters. I asume that the question wants that i arange the given random number into those intervals

[Sam Chak]

Hey @JACK, if YES exactly, please edit your question for clarity so that you get meaningful Answers.

[Rena Berman]

(Answers Dev) Restored edit

Answer 1

[KALYAN ACHARJYA]

Hint: rand

https://in.mathworks.com/help/matlab/ref/rand.html

[JACK]

Thanks !!! , may i get a hint relatet how to manage to use the for/if loops.

u = rand (20,1)

quantile(u,[0.2,0.4,0.6,0.8])

I worte smth like this to get some first results

[Steven Lord]

There's no such thing as an "if loop", but as for a for loop how would you solve the problem if the quantile function only accepted a scalar (one number, not a vector) as its first input?

Once you've written that code, replace the call to the quantile function with an if / elseif / else / end block.

% Save this as countVonCount.m :)
x = 3;
if x == 1
    disp("One!")
elseif x == 2
    disp("Two!")
elseif x == 3
    disp("Three!")
else
    disp("Ah ah ah!")
end

Three!

[KALYAN ACHARJYA]

@JACK Are you wish to write your own code for quantile function using for loop or if ..any whatever?

Answer 2

[Torsten]

n = 20;
r = zeros(n,1)
for i=1:n
    r(i) = rand;
    if r(i) < 0.25
        quarter(i) = ...
    elseif r(i) >=0.25 && r(i) < 0.5
        ...
    elseif 
        ...
    else
        ...
    end
end

Can you take it from here ?

[Image Analyst]

Will you get in trouble if you turn in @Torsten's solution as your own and your professor finds out? Would you face disciplinary action for cheating?

[Torsten]

@JACK

That's the sceleton - you must add the flesh.

[Sam Chak]

@JACK, Your QUESTION has DISAPPEARED!!!

[JACK]

@Image Analyst Well i don't know, im omw to gather some information. I will not turn in the solution of Torsten's.

[JACK]

@Torsten hey Torsten well i added the flesh. The only part that i don't get is quarter(i) = ... part. I managed to fill the other parts but cant define what to add to the ... seciton :S

[JACK]

@Torsten

n = 20;

r = zeros(n,1)

for i=1:n

r(i) = rand;

if r(i) < 0.25

quarter(i) = ...

elseif r(i) >=0.25 && r(i) < 0.5

elseif

r(i) >=0.5 && r(i) < 0.75

else

r(i) >=0.75 && r(i) < 1

end

end

[Sam Chak]

@JACK, You don't have to follow exactly. Basically, you create four quarter groups and if the r(i) number satisfies one out of the 4 conditional statements, then that number will be dumped into that group.

Answer 3

[Walter Roberson]

hint: floor(n*4)

But be careful with the exact boundaries that are multiples of 1/4. For each of those exact values you should write down which bin you want to result, and test your code to make sure it gives those results.

0, ¼, ½, ¾, 1 is five boundaries not 4, and you need to design with that in mind.