Thread: White needs help

So, I'm supposed to be writing a piece of MATLAB code to approximate cos to 8 sig figs. Seems easy right? It seems easy to me, but for some reason, I can't figure out why my while loop won't stop after 8 sig figs are reached. Any help/hints would be appreciated. Keep in mind that this is the first coding I've done in about 2 years.

Code:

clear

x=.3*pi;

n=2; %number of sig figs
es=0.5*10^(2-n); %target error

et=1; %actual error
trueVal=cos(x);

term(1)=1;
counter=2;
while (abs(et)>=es)
    counter1=(counter-1)*2;
    term(counter)=((-1)^(counter-1))*(x^counter1)/factorial(counter1);
    total=sum(term);
    et=((trueVal-total)/trueVal)*100;
    counter=counter+1;
end

I also have tried to meet with the professor, but he's in a meeting right now and only meets with students by appointment. The project is due on Monday so I've got some time.

I also set the number of sig figs low in the above to see if it was just a long run time, but from removing the semi-colon on the counter var above, I've seen that the code is running into very high iterations.

Originally Posted by DJ Mr. White

I also set the number of sig figs low in the above to see if it was just a long run time, but from removing the semi-colon on the counter var above, I've seen that the code is running into very high iterations.

Lol....I came in, hoping I could help. I had to read that sentence twice......but I knew it was WAY over my head about half way through, the first time.

Good luck.

Repost From Scripting About Sig Fig Functions | TheDailyReviewer
http://mathfax.com/search/do_sig_figs
I can't help but maybe google can.

I have to shut down MatLab using Process Explorer to get it to stop running. I've seen it running as high as 180k iterations. I can't figure out what's up.

I'll try and try that.