function [trainInfo, testInfo, classifierInfo] = leastSquaresRegressor(trainX, trainY, testX, params); 
%A function to compute least squares regression on the data. No bias term here, so might need to center the data.   

if nargin < 3
    fprintf('%s\n', help('leastSquaresRegressor'));
    error('Incorrect number of inputs - see above usage instructions.');
end

trainData = data; 
trainData = addDataField(trainData, 'X', trainX, 'examples'); 
trainData = addDataField(trainData, 'Y', trainY, 'labels'); 

testData = data; 
testData = addDataField(testData, 'X', testX, 'examples'); 

[classifierInfo, trainInfo] = leastSquaresRegressorTrain(trainData, params);
[testInfo, predictionInfo] = leastSquaresRegressorPredict(trainData, testData, classifierInfo, params);

clearAllFields(trainData); 
clearAllFields(testData);