matlab - Chance level accuracy for clearly separable data -

-

i have written believe quite simple svm-classifier [svm = support vector machine]. "testing" distributed data different parameters, classifier returning me 50% accuracy. wrong?

here code, results should reproducible:

features1 = normrnd(1,5,[100,5]); features2 = normrnd(50,5,[100,5]); features = [features1;features2]; labels = [zeros(100,1);ones(100,1)];  %% svm-classification nrfolds = 10; %number of folds of crossvalidation kernel = 'linear'; % 'linear', 'rbf' or 'polynomial' c = 1; % c 'boxconstraint' parameter.   cvfolds = crossvalind('kfold', labels, nrfolds);   = 1:nrfolds                            % iterate through each fold     testidx = (cvfolds == i);                % indices test instances     trainidx = ~testidx;                     % indices training instances      % train svm     cl = fitcsvm(features(trainidx,:), labels(trainidx),'kernelfunction',kernel,'standardize',true,...     'boxconstraint',c,'classnames',[0,1]);      [label,scores] =  predict(cl, features(testidx,:));     eq = sum(labels(testidx));     accuracy(i) = eq/numel(labels(testidx));  end  crossvalacc = mean(accuracy)

you not computing accuracy correctly. need determine how many predictions match original data. summing total number of 1s in test set, not actual number of correct predictions.

therefore must change eq statement this:

eq = sum(labels(testidx) == label);

recall labels(testidx) extracts true label test set , label predicted results svm model. correctly generates vector of 0/1 0 means prediction not match actual label test set , 1 means agree. summing on each time agree, or each time vector 1 way compute accuracy.


Comments

Post a Comment

Popular posts from this blog

ios - MKAnnotationView layer is not of expected type: MKLayer -

-
Image
so code works fine logger riddled message. there way rid of or suppress it? postannotation.swift class postannotation: mkpointannotation { //mark: properties let post: post //mark: initialization init(post: post) { self.post = post super.init() self.coordinate = cllocationcoordinate2d(latitude: post.latitude, longitude: post.longitude) self.title = post.title self.subtitle = post.timestring() } } adding annotation let annotation = postannotation(post: post) self.map.addannotation(annotation) func mapview func mapview(_ mapview: mkmapview, viewfor annotation: mkannotation) -> mkannotationview? { if annotation mkuserlocation { return nil } var annotationview = mapview.dequeuereusableannotationview(withidentifier: "pin") as? mkpinannotationview if annotationview == nil { annotationview = mkpinannotationview(annotation: annotation, reuseidentifier: "pin")
Read more

ZeroMQ on Windows, with Qt Creator -

-
i have installed zmq link given below on windows 7. http://zeromq.org/distro:microsoft-windows 1) have c++ project in qt-creator , i'm using zmq c++ binding (zhelpers.hpp etc). 2) have added .lib installed zmq folder qtcreator 3) while compiling, compiler looks _imp__zmq_verion, in .dll files present in .lib have __imp_zmq_version. 4) causing undefined reference zmq_version. anyone else faced problem , has solution ?
Read more

unity3d - Unity SceneManager.LoadScene quits application -

-
i have 2 different scenes 1 named 'main' , other 'game' both added scenes in load. when use scenemanager.loadscene("game"); works no problem when tried return main scene code if (input.getkeydown (keycode.escape)) { scenemanager.loadscene("main"); } strangely game quits. thanks. sorry interruption. somewhere on other script found code. if (input.getkeydown (keycode.escape)) { application.quit (); } that's bad, know...
Read more