MATLAB: While running this matlab code the value of x(513) is infinite value.But while calculating manually it is a finite value only.
accessing index in an arraybasics of matlab
x(1)=3.58;
for i=2:(513)
x(i)=4*(x(i-1));
end
Why this kind of error is happening in matlab?
Best Answer
Because your calculation exceeds the largest value that can be represented using thefloating point class double:
>> realmax()
ans = 1.7977e+308
and values larger than that are represented as Inf. The second-to-last value is1.6089e+308 which you then multiply by four to get Inf. There is no surprise there, this is the expected behavior.
Note also that you can easily generate this vector more efficiently without a loop:
cumprod([3.58,4*ones(1,512)])
All beginners need to learn what floating point numbers are and how to work with them, otherwise their numeric calculations can easily turn into meaningless rubbish. For a readable introduction to floating point arithmetic, look at Cleve's Corner article from 1996:Floating Points.
Best Answer