fprintf not displaying in loop

ive tried for and while loops for this. if its outside of the loop, it prints fine, but not inside, can someone help me understand why it doesnt work

clear
clc
Year = [2019 2020 2021 2023 2024 2026];
Month = [ 7 12 12 4 4 8];
Day = [ 2 14 4 20 8 12];
budget = input('what is your required budget?    $');
saveRate = input('how much will you save per day?    $');
savingsI = input('what is your initial savings?    $');
dateI = 1 + 30.44 * 0 + 365.2425 * 2017;
dateF = Day + 30.44 .* Month + 365.2425 .* (Year - 1);
daysT = dateF - dateI;
savings = daysT .* saveRate + savingsI; 
fprintf('with a required budget of $%d, you can attend the following total solar eclipse(s)\n',budget)
while savings > budget
    fprintf('A total solar eclipse that occurs at %4.0f days with a savings balance of $%4.0f\n',[daysT;savings])
end

Answer 1

[Geoff Hayes]

hubert - you may need to clarify what you mean by if its outside of the loop, it prints fine, but not inside. If I run your code, with random inputs such that your while condition is always satisfied, then I get "stuck" in the loop with the same line or lines being printed out until I cancel the program. Look closely at

while savings > budget
    fprintf('A total solar eclipse that occurs at %4.0f days with a savings balance of $%4.0f\n',[daysT;savings])
end

One problem is that budget is a scalar and that savings could be an array. What is your intention with the comparison of

savings > budget

? Should all elements in the savings array be compared to budget? Since there is no change to either savings or budget in the body of the loop, then you will never exit the looo until you cancel the running program.

Perhaps what you intend is something like

for k = 1:length(savings)
    if savings(k) > budget
        fprintf('A total solar eclipse that occurs at %4.0f days with a savings balance of $%4.0f\n',daysT(k), savings(k));
    end
end

Or not?

[Amin Kassab-Bachi]

I think I'm having a similar issue here. Basically, I'm running a for loop, and at the end of each iteration I want matlab to print the number of the finished iteration. but matlab holds all printing (looks as if it's frozen) untill I cancel the loop or it's done, then suddenly all of the statements are printed. So, it's not that fprintf is not working, but the GUI just gets stuck while MATLAB is working on something large. I noticed similar issues in Python as well.

The solution is to add a small pause at the end of the loop, half a second should be sufficient.