%?Time?Series?Trend?Detection?Tests
%?[?z?sl?lcl?ucl?]?=?trend（?y?dt?）
%?where?z?=?Mann-Kendall?Statistic
%?sl?=?Sen‘s?Slope?Estimate
%?lcl?=?Lower?Confidence?Limit?of?sl
%?ucl?=?Upper?Confidence?Limit?of?sl
%?y?=?Time?Series?of?Data
%?dt?=?Time?Interval?of?Data
%y是待檢測數據序列
function?[?z?sl?lcl?ucl?]?=?mk（?y?）
n?=?length（?y?）;
dt=1;

%?Mann-Kendall?Test?for?N?>?40
????%?disp（?‘Mann-Kendall?Test;‘?）;
????%?if?n?????%?disp（?‘WARNING?-?sould?be?more?than?40?points‘?）;
????%?end;

%?calculate?statistic
s?=?0;
for?k?=?1:n-1
????for?j?=?k+1:n
????????s?=?s?+?sign（?y（j）?-?y（k）?）;
????end;
end;

%?variance?（?assuming?no?tied?groups?）
v?=?（?n?*?（?n?-?1?）?*?（?2?*?n?+?5?）?）?/?18;

%?test?statistic
if?s?==?0
z?=?0;
elseif?s?>?0
z?=?（?s?-?1?）?/?sqrt（?v?）;
else
z?=?（?s?+?1?）?/?sqrt（?v?）;
end;?

%?should?calculate?Normal?value?here
nor?=?1.96;
%?results
disp（?[?‘?n?=?‘?num2str