function?ROCdata=roc（varargin）
%?ROC?-?Receiver?Operating?Characteristics.
%?The?ROC?graphs?are?a?useful?tecnique?for?organizing?classifiers?and
%?visualizing?their?performance.?ROC?graphs?are?commonly?used?in?medical
%?decision?making.
%?If?you?have?downloaded?partest
%?http://www.mathworks.com/matlabcentral/fileexchange/12705
%?the?routine?will?compute?several?data?on?test?performance.
%
%?Syntax:?roc（xalpha）
%
%?Input:?x?-?This?is?the?data?matrix.?The?first?column?is?the?column?of?the?data?value;
%????????????The?second?column?is?the?column?of?the?tag:?unhealthy?（1）?and
%????????????healthy?（0）.
%??????????alpha?-?significance?level?（default?0.05）
%
%?Output:?The?ROC?plot;
%?????????The?Area?under?the?curve?with?Standard?error?and?Confidence
%?????????interval?and?comment.
%?????????Cut-off?point?for?best?sensitivity?and?specificity.
%?????????（Optional）?the?test?performances?at?cut-off?point.
%
%?Example:
%???????????load?rocdata
%???????????roc（x）
%
%???????????Created?by?Giuseppe?Cardillo
%???????????giuseppe.cardillo-edta@poste.it
%
%?To?cite?this?file?this?would?be?an?appropriate?format:
%?Cardillo?G.?（2008）?ROC?curve:?compute?a?Receiver?Operating?Characteristics?curve.
%?http://www.mathworks.com/matlabcentral/fileexchange/19950

%Input?Error?handling
args=cell（varargin）;
nu=numel（args）;
if?isempty（nu）
????error（‘Warning:?almost?the?data?matrix?is?required‘）
elseif?nu>3
????error（‘Warning:?Max?three?input?data?are?required‘）
end
default.values?=?{[]0.051};
default.values（1:nu）?=?args;
[x?alpha?verbose]?=?deal（default.values{:}）;
if?isvector（x）
????error（‘Warning:?X?must?be?a?matrix‘）
end
if?~all（isfinite（x（:）））?||?~all（isnumeric（x（:）））
????error（‘Warning:?all?X?values?must?be?numeric?and?finite‘）
end
x（:2）=logical（x（:2））;
if?all（x（:2）==0）
????error（‘Warning:?there?are?only?healthy?subjects!‘）
end
if?all（x（:2）==1）
????error（‘Warning:?there?are?only?unhealthy?subjects!‘）
end
if?nu>=2
????if?~isscalar（alpha）?||?~isnumeric（alpha）?||?~isfinite（alpha）?||?isempty（alpha）
????????error（‘Warning:?it?is?required?a?numeric?finite?and?scalar?ALPHA?value.‘）;
????end
????if?alpha?<=?0?||?alpha?>=?1?%check?if?alpha?is?between?0?and?1
????????error（‘Warning:?ALPHA?must?be?comprised?between?0?and?1.‘）
????end
????if?nu==3
????????verbose=logical（verbose）;
????end
end
clear?args?default?nu

tr=repmat（‘-‘180）;
lu=length（x（x（:2）==1））;?%number?of?unhealthy?subjects
lh=length（x（x（:2）==0））;?%number?of?healthy?subjects
z=sortrows（x1）;
%find?unique?values?in?z
labels=unique（z（:1））;
ll=length（labels）;?%count?unique?value
a=zeros（ll2）;?%array?preallocation
ubar=mean（x（x（:2）==1）1）;?%unhealthy?mean?value
hbar=mean（x（x（:2）==0）1）;?%healthy?mean?value
for?K=1:ll
????if?hbar????????TP=length（x（x（:2）==1?&?x（:1）>labels（K）））;
????????FP=length（x（x（:2）==0?&?x（:1）>labels（K）））;
????????FN=length（x（x（:2）==1?&?x（:1）<=labels（K）））;
????????TN=length（x（x（:2）==0?&?x（: