Predicting Mortality of ICU Patients: The PhysioNet/Computing in Cardiology Challenge 2012 1.0.0

File: <base>/sources/alistairewj_at_gmail.com/entry10/physionet2012.m (2,392 bytes)
function [prob,died]=physionet2012(tm,category,val)
% [prob,died]=physionet2012(tm,category,val) 
%   Submission for the PhysioNet 2012 Challenge.
%
%	Inputs:
% tm      - (Nx1 Cell Array) Cell array containing time of measurement
% category- (Nx1 Cell Array) Cell array containing type (category)
%           measurement
% value   - (Nx1 Cell Array) Cell array containing value of measurement
%
%	Outputs:
% prob    - (Scalar) Probability value of the patient dying in the hospital
% died    - (Logical) Binary classification if the patient is going to die
%           on the hospital (1 - Died, 0 - Survived)
%
%	Example
%       [prob,died]=physionet2012(tm,category,val)

%	Copyright 2012 Alistair Johnson

%	$LastChangedBy: alistair $
%	$LastChangedDate: 2012-05-29 09:01:11 -0400 (Tue, 29 May 2012) $
%	$Revision: 1 $
%	Originally written on GLNXA64 by Alistair Johnson, 24-Apr-2012 14:02:25
%	Contact: alistairewj@gmail.com

%=== Miscellanious default values
T=0.330400; % Mortality threshold that maximizes SE/PPV

%=======================%
%=== PREPROCESS DATA ===%
%=======================%
%=== Put into expected format for function
if nargin<3
    if iscell(tm) && size(tm,2)>=3
        data = tm; % assume multi-observation input
    else
        error('Incorrect input.');
    end
elseif nargin==3
    % Convert time from string to numeric minutes
    tm = cellfun(@(x) str2double(x(1:2)), tm)*60 + cellfun(@(x) str2double(x(4:5)),tm);
    data = [{1},{tm},{category},{val}];
end
data = pnPreprocess(data,0);


%==================%
%=== LOAD MODEL ===%
%==================%
model = load('pnEntry10.mat');

%===============================%
%=== MODEL FEATURE SELECTION ===%
%===============================%
% if isfield(model,'idxRem')
% %=== Parse data for problematic features
% [X,header] = pnParseData(X,header,idxRem);
% end


%===============================%
%=== MODEL PARSING ===%
%===============================%
% if isfield(model,'T')
%     T = model.T;
% end
header = model.header;
model = model.model;

%=====================%
%=== LOAD FEATURES ===%
%=====================%
[X,header2] = pnBaseFeatures(data,header);
X(X<0) = NaN;

%===================%
%=== CLASSIFY ======%
%===================%
prob = pnBRFApply(model,X);

%===================%
%=== SET OUTPUTS ===%
%===================%
died = prob >= T; % Thresholded probability to maximize PPV/Sens

end