I also used this code. Thanks, it helps me a lot.
Time needed to calculate apen is depending on the data size, obviously.
I used this code to calculate entropy for 7200 datapoints. It took me about 10 min to get a result. you have to wait for a while.
Firstly your algorithm works very well on a windows machine,and i have to thank you because you help me a lot...
Secondly, i have one problem when i run your algorithm and if you could help me i wll appreciate it a lot..Well, when i try to run your algorithm,using a multi-sample-signal it does not provide any results(eg [apen] = approx_entropy(2000,0.5,a)).It only shows that it is in busy mode for a long time so i have to exit from matlab.On the contrary,when I am trying to run it using an one-sample-signal(eg "sine") with 10 samples,it provides me results.So,I believe that the algorithm's disfunction depends on the amount of the samples I use when I am running it.
Thank you for your time!!