I need to find out what this program is missing

I'm trying to use this program to calculate the cos of a given(prompted) angle in degrees.

A=input('Enter angle:');
x=(pi/180)*A; 
format long
a=0;c=0;sg=1;
while 
    c=c+sg*((x^(2*a))/(factorial(2*a))); % Infinite series calculation.
    a=a+1;sg=-sg;
end
fprintf('cos = %6f',c);

I get no answer and I have to close Matlab and restart.

[Yash]

what error did u got?

[Aaron]

There was no error. It was just blank. And it was like Matlab was stuck. I could not even input anything new, like "clc" to clear everything.

[Albert Yam]

If you are stuck in a loop. (See 'Busy' in the bottom left.) hit Ctrl+C

[Ryan]

This should help: TUTORIAL: how to format your question with markup.

Answer 1

[Albert Yam]

while [condition] %that should only be true to run the loop
   %stuff in loop
end % make sure to end the loop, but should give a warning about that

If your condition is just a constant, than your loop is always running. But your code is not 'copy/paste'-able into Matlab for us to check.

[Aaron]

I need to have my condition for x be accurate to 6 digits after the decimal. I've made the changes below:

A=input('Enter angle:');%angle in degrees x=(pi/180)*A; % radians n=input('Enter the number of places; ') format long a=0;c=0;sg=1; while a~=n % New condition. c=c+sg*((x^(2*a))/(factorial(2*a))); % Infinite series calculation. a=a+1;sg=-sg; end fprintf('%6f',c);

This worked but is there a way to prevent from needing this new condition?

Also how to I return the ">>" instead of leaving it after the answer shown beloow:

>> cosx Enter angle:-30 Enter the number of places; 6 0.866025>> % I need the >> to be on the next line.

[Jan]

Please follow the "About Matlab Answers" link to learn more about the forum, e.g. how code is formatted. Thanks.

[Albert Yam]

A=input('Enter angle:');%angle in degrees 
x=(pi/180)*A; % radians 
n=input('Enter the number of places; ') 
format long 
a=0;c=0;sg=1; 
while a~=n % New condition. 
c=c+sg*((x^(2*a))/(factorial(2*a))); % Infinite series calculation. 
a=a+1;sg=-sg; 
end 
fprintf('%6f',c);

You can always just hardcode n=6, in the condition, since you said it is a 'need'. While loops need a condition, how else would it know to stop looping (your previous problem)? Unless you know exactly how many times to loop (For loop). For the '>>' on the next line,

fprintf('%6f\n',c);

Please use the {}code formatting next time. It is easier for people to copy/paste into Matlab to see what is wrong.

A=input('Enter angle:');%angle in degrees x=(pi/180)*A; % radians n=input('Enter the number of places; ') format long a=0;c=0;sg=1; while a~=n % New condition. c=c+sg*((x^(2*a))/(factorial(2*a))); % Infinite series calculation. a=a+1;sg=-sg; end fprintf('%6f',c);

Comments out everything after the A=input

[Aaron]

I will remember to use the {} next time. Thank you for your help.