function?saen?=?SampEn（?dim?r?data?tau?）
%?SAMPEN?Sample?Entropy
%???calculates?the?sample?entropy?of?a?given?time?series?data

%???SampEn?is?conceptually?similar?to?approximate?entropy?（ApEn）?but?has
%???following?differences:
%???????1）?SampEn?does?not?count?self-matching.?The?possible?trouble?of
%???????having?log（0）?is?avoided?by?taking?logarithm?at?the?latest?step.
%???????2）?SampEn?does?not?depend?on?the?datasize?as?much?as?ApEn?does.?The
%???????comparison?is?shown?in?the?graph?that?is?uploaded.

%???dim?????:?embedded?dimension
%???r???????:?tolerance?（typically?0.2?*?std）
%???data????:?time-series?data
%???tau?????:?delay?time?for?downsampling?（user?can?omit?this?in?which?case
%?????????????the?default?value?is?1）
%
%---------------------------------------------------------------------
%?coded?by?Kijoon?Lee??kjlee@ntu.edu.sg
%?Mar?21?2012
%---------------------------------------------------------------------

if?nargin?if?tau?>?1?data?=?downsample（data?tau）;?end

N?=?length（data）;
correl?=?zeros（12）;
dataMat?=?zeros（dim+1N-dim）;
for?i?=?1:dim+1
????dataMat（i:）?=?data（i:N-dim+i-1）;
end

for?m?=?dim:dim+1
????count?=?zeros（1N-dim）;
????tempMat?=?dataMat（1:m:）;
????
????for?i?=?1:N-m
????????%?calculate?Chebyshev?distance?excluding?self-matching?case
????????dist?=?max（abs（tempMat（:i+1:N-dim）?-?repmat（tempMat（:i）1N-dim-i）））;
????????
????????%?calculate?Heaviside?function?of?the?distance
????????%?User?can?change?it?to?any?other?function
????????%?for?modified?sample?entropy?（mSampEn）?calculation
????????D?=?（dist?????????
????????count（i）?=?sum（D）/（N-dim）;
????end
????
????correl（m-dim+1）?=?sum（count）/（N-dim）;
end

saen?=?log（correl（1）/correl（2））;
end

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????1785??2018-04-23?16:47??SampEn.m
?????目錄???????????0??2018-05-05?01:08??__MACOSX\
?????文件?????????605??2018-04-23?16:47??__MACOSX\._SampEn.m