matlab - Decision Level Fusion of SVR outputs -
i have 2 sets of features predicting same outputs. instead of training @ once, train them separately , fuse decisions. in svm classification, can take probability values classes can used train svm. in svr, how can this?
any ideas?
thanks :)
there couple of choices here . 2 popular ones be:
one)
build 2 models , average results.
it tends work in practice.
two)
you in similar fashion when have probabilities. problem is, need control on fitting .what mean is "dangerous" produce score 1 set of features , apply labels same before (even if new features different). because new applied score trained on these labels , therefore on fits in (hyper-performs).
normally use cross-validation
in case have
- train_set_1 x1 features , label y
- train_set_2 x2 features , same label y
some psedo code:
randomly split 50-50 both train_set_1 , train_set_2 @ same points along y (output array)
so have:
a.train_set_1 (50% of training_set_1) b.train_set_1 (the rest of 50% of training_set_1) a.train_set_2 (50% of training_set_2) b.train_set_2 (the rest of 50% of training_set_2) a.y (50% of output array corresponds same sets a.train_set_1 , a.train_set_2) b.y (50% of output array corresponds same sets b.train_set_1 , b.train_set_2)
here key part
build svr a.train_set_1 (that contains x1 features) , output a.y , apply model's prediction feature b.train_set_2 . mean, score b.train_set_2 base on first model. take score , paste next a.train_set_2 .so set have x2 features + 1 more feature, score produced first model. build final model on b.train_set_2 , b.y
the new model , although uses score produced training_set_1, still in unbiased way , since later never trained on these labels!
you might find paper quite useful
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