%PREX_REGR PRTools regression example%% Show the regression functions that are available in Prtools in a 1-D% example.%help prex_regr;% Define the dataset parameters and generate the data:n = 25; sig = 0.2;a = gendatsinc(n,sig); % trainb = gendatsinc(n,sig); % test% Train several regression functions:w1 = a*linearr([],1e-9);w2a = a*nu_svr([],'r',2,0.01,'epsilon',0.1);w2b = a*svmr([],0.01,'r',2);w3 = a*ridger([],10);w4a = a*lassor([],10);w4b = a*lassor([],1);w5a = a*ksmoothr([],1);w6 = a*pinvr;w7 = a*plsr;w8 = a*knnr([],1);% Plot the functions in the scatterplot of the data:figure(1); clf; hold on;scatterr(a);plotr(w1,'b-');plotr(w2a,'r-');plotr(w2b,'r--');plotr(w3,'g-');plotr(w4a,'k-');plotr(w4b,'k--');plotr(w5a,'m-');plotr(w6,'y-');plotr(w7,'c-');plotr(w8,'b--');% Show the MSE results:fprintf('                           MSE\n');fprintf('linear regression      : %f\n', b*w1*testr);fprintf('nu-svm regression      : %f\n', b*w2a*testr);fprintf('svm regression         : %f\n', b*w2b*testr);fprintf('ridge regression       : %f\n', b*w3*testr);fprintf('lasso regression (C=10): %f\n', b*w4a*testr);fprintf('lasso regression (C=1) : %f\n', b*w4b*testr);fprintf('smoother regression    : %f\n', b*w5a*testr);fprintf('pseudo-inv regression  : %f\n', b*w6*testr);fprintf('partial least squares  : %f\n', b*w7*testr);fprintf('kNN regression         : %f\n', b*w8*testr);