Debugging an Infinite Loop in MATLAB

[balogun]

Homework Statement

I am having a bit of a problem trying to understand while loop.

I was given a question lke this

Write a while loop to evaluate the spl of effective pressure p starting from pref and increasing by a factor of 2 at a time.The program should stop when the spl exceeds 100 db.The output should clearly show p and spl at each step

pref=20x10-6 spl=20log10(p/pref)



But it keeps making MATLAB crash by giving me an infinite loop.

Homework Equations

The Attempt at a Solution

My code was like this

pref=2/1000000;
p=pref;
spl=20*log(10);
while spl<100;
spl=20*log(10)*(p/pref)
p=p^2
end

 

[CEL]

Homework Statement

I am having a bit of a problem trying to understand while loop.

I was given a question lke this

Write a while loop to evaluate the spl of effective pressure p starting from pref and increasing by a factor of 2 at a time.The program should stop when the spl exceeds 100 db.The output should clearly show p and spl at each step

pref=20x10-6 spl=20log10(p/pref) But it keeps making MATLAB crash by giving me an infinite loop.

Homework Equations

The Attempt at a Solution

My code was like this

pref=2/1000000;
p=pref;
spl=20*log(10);
while spl<100;
spl=20*log(10)*(p/pref)
p=p^2
end

Homework Statement

Homework Equations

The Attempt at a Solution

Of course you have an infinite loop. Your stopping parameter [B}spl[/B] is constant and equal to 20 times the natural logarithm of 10, when it should be 20 times the logarithm in the base 10 of p/pref.
Your code should be:

pref=2/1000000;
p=pref;
spl=20*log10(p/pref);
while spl<100;
spl=20*log10(p/pref)
p=p^2
end

 

[piercas]

Hello, it seems like your while loop is not incrementing the value of p properly. In each iteration, the value of p should be multiplied by 2 (since the problem asks for an increase by a factor of 2 at each step). Your current code is squaring p in each iteration, which will quickly lead to a very large value of p and cause an infinite loop.

Try modifying your code to:

pref = 2/1000000;
p = pref;
spl = 20*log10(p/pref);

while spl < 100
p = p*2;
spl = 20*log10(p/pref);
end

This should properly increment the value of p and stop the loop once the spl exceeds 100 dB. Also, make sure to include a semicolon at the end of the line where you calculate the value of spl, otherwise it will print out the value at each iteration and make the output messy.

I hope this helps with debugging your code. Keep in mind that while loops can be tricky and it's important to carefully check your code for any potential errors. Good luck with your assignment!