Need to create an array that consists of 5 numbers found through a while loop

I am creating a game where you loop through a while loop and get a random number between set values. If your number is within a range you get points and that is added to your total. I am trying to also display the values (distance) you get in the command window with fprintf but I am getting a struct value for the array. I have tried multiple struct commands and was eventually able to get it to a cell, but was unable to print. I am also unable to get my append to work. So how do I save these values as I loop through my function and print it out.

userInput = input("Which car variation are you testing?\n1. Gatorade wheels, gatorade bottle\n2. Gatorade wheel, water bottle\n" + ...
    "3. Water bottle wheels, gatorade bottle\n4. Water bottle wheels, water bottle\n");

score = 0;
if userInput == 1
   count = 0;
   while count < 5
        a = 10;
        b = 20;
        distance = (b-a).*rand(1,1) + a;
        array = [];
        array.append = distance;
        distance1 = distance(count);
        count = count + 1;
        if distance >= 15 && distance <= 18
            score = score + 3;
        elseif distance < 18
            score = score + 1;
        elseif distance < 15
            score = score + 1;
        end 
    end
elseif userInput == 2

elseif userInput == 3

elseif userInput == 4

else
    printf("Sorry, we could not perform your test.");

end
fprintf("You travelled %d and your total score is: %3.0f", array, score);

[Alex B]

MATLAB doesn't support Python style vector.append() operations. What you're doing here is creating a new field called 'append' and adding the value of 'distance' to it.

Equivalent syntaxes could be:

array(end+1) = distance;
array = [array, distance];

Additionally, you're clearing the value of array on each loop, move the

array = [];

Expression outside the while loop.

Finally, remember that MATLAB indexes from 1, not 0. You initialize your counter to 0 then try to index a list with it, which will throw errors. Finally, it looks like the expression

distance1 = distance(count)

should be:

distance1 = array(count)

The way you've defined distacne means it will only ever have one element, while array will grow as the script progresses. You may also want to review how your print statement is working at the end, since it will print once per element in array the way it's written currently.

[Jacob]

I did the distance1 thing as a lets see what this does and proceed I just forgot to erase it before i asked this question. I fixed the array = []; and the array(end+1) but im getting an array size of 1x10 instead of 5 do you know why this could be.

[Walter Roberson]

        if distance >= 15 && distance <= 18
            score = score + 3;
        elseif distance < 18
            score = score + 1;
        elseif distance < 15
            score = score + 1;
        end 

Consider a distance value < 15. It would fail the >= 15 & <= 18 test so it would move to the elseif. Since it is < 15 it is certainly < 18 so it would pass the < 18 test. Having succeeded on that test, it would not use the "elseif" comparison against 15.

I suspect the desired test is elseif distance > 18

Note that if the requirement is for the score to be incremented by 1 whenver the distance is outside the range 15 to 18, then you could do that with a simple "else" (unless somehow the distance can end up being nan in which case specific tests for > 18 and < 15 would exclude the nan case.)

Answer 1

[Stephen23]

Take a look at this line:

array.append = distance;

You looks as if you are trying to write Python code. However, MATLAB does not have lists and it certainly does not have methods (e.g. APPEND) that operate on lists. The MATLAB approach is to use indexing:

userInput = 1;
score = 0;
array = [];
if userInput == 1
    count = 0;
    while count < 5
        a = 10;
        b = 20;
        distance = (b-a).*rand(1,1) + a;
        array(end+1) = distance;
        count = count + 1;
        if distance >= 15 && distance <= 18
            score = score + 3;
        elseif distance < 18
            score = score + 1;
        elseif distance < 15
            score = score + 1;
        end 
    end
elseif userInput == 2
elseif userInput == 3
elseif userInput == 4
else
    printf("Sorry, we could not perform your test.");
end
fprintf("You travelled %g and your total score is: %u", array(end), score);

You travelled 17.062 and your total score is: 10

[Jacob]

this worked thank you so much!