示例#1
0
def test_ensemble_nystrom_full_prec_one_learner():
    # test if keep all the dimensions is the nystrom kernel matrix equals to the exact kernel
    n_sample = 150
    n_feat = n_sample
    input_val1 = torch.DoubleTensor(
        np.random.normal(size=[n_sample, n_feat])).double()
    input_val2 = input_val1
    # input_val2  = torch.DoubleTensor(np.random.normal(size=[n_sample - 1, n_feat] ) ).double()
    # get exact gaussian kernel
    kernel = GaussianKernel(sigma=10.0)
    kernel_mat = kernel.get_kernel_matrix(input_val1, input_val2)

    # nystrom method
    approx = Nystrom(n_feat, kernel=kernel)
    approx.setup(input_val1)
    feat = approx.get_feat(input_val1)
    approx_kernel_mat = approx.get_kernel_matrix(input_val1, input_val2)

    # ensembleed nystrom method
    approx_ensemble = EnsembleNystrom(n_feat, n_learner=1, kernel=kernel)
    approx_ensemble.setup(input_val1)
    feat_ensemble = approx_ensemble.get_feat(input_val1)
    approx_kernel_mat_ensemble = approx_ensemble.get_kernel_matrix(
        input_val1, input_val2)
    np.testing.assert_array_almost_equal(
        np.sum(feat.cpu().numpy()**2), np.sum(feat_ensemble.cpu().numpy()**2))

    np.testing.assert_array_almost_equal(
        np.sum(approx_kernel_mat.cpu().numpy()**2),
        np.sum(approx_kernel_mat_ensemble.cpu().numpy()**2))
    print("single learner ensembled nystrom test passed!")
示例#2
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def test_ensemble_nystrom_full_prec_three_learner():
    # test if keep all the dimensions is the nystrom kernel matrix equals to the exact kernel
    n_sample = 150
    n_feat = n_sample
    input_val1 = torch.DoubleTensor(
        np.random.normal(size=[n_sample, n_feat])).double()
    input_val2 = input_val1
    # input_val2  = torch.DoubleTensor(np.random.normal(size=[n_sample - 1, n_feat] ) ).double()
    # get exact gaussian kernel
    kernel = GaussianKernel(sigma=10.0)
    kernel_mat = kernel.get_kernel_matrix(input_val1, input_val2)

    # nystrom method
    approx = Nystrom(n_feat, kernel=kernel)
    approx.setup(input_val1)
    feat = approx.get_feat(input_val1)
    approx_kernel_mat = approx.get_kernel_matrix(input_val1, input_val2)

    # ensembleed nystrom method
    approx_ensemble = EnsembleNystrom(n_feat, n_learner=3, kernel=kernel)
    approx_ensemble.setup(input_val1)
    feat_ensemble = approx_ensemble.get_feat(input_val1)
    assert feat_ensemble.size(0) == n_sample
    assert feat_ensemble.size(1) == n_feat
    approx_kernel_mat_ensemble = approx_ensemble.get_kernel_matrix(
        input_val1, input_val2)
    print("single learner ensembled nystrom test passed!")
示例#3
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def test_ensemble_nystrom_low_prec():
    # test if keep all the dimensions is the nystrom kernel matrix equals to the exact kernel
    n_sample = 150
    n_feat = n_sample
    input_val1 = torch.DoubleTensor(
        np.random.normal(size=[n_sample, n_feat])).double()
    input_val2 = input_val1
    # input_val2  = torch.DoubleTensor(np.random.normal(size=[n_sample - 1, n_feat] ) ).double()
    # get exact gaussian kernel
    kernel = GaussianKernel(sigma=10.0)
    kernel_mat = kernel.get_kernel_matrix(input_val1, input_val2)

    # setup quantizer
    quantizer = Quantizer(4,
                          torch.min(input_val1),
                          torch.max(input_val1),
                          rand_seed=2,
                          use_cuda=False)

    # nystrom method
    approx = Nystrom(n_feat, kernel=kernel)
    approx.setup(input_val1)
    feat = approx.get_feat(input_val1)
    approx_kernel_mat = approx.get_kernel_matrix(input_val1, input_val2,
                                                 quantizer, quantizer)

    # ensembleed nystrom method
    approx_ensemble = EnsembleNystrom(n_feat, n_learner=1, kernel=kernel)
    approx_ensemble.setup(input_val1)
    feat_ensemble = approx_ensemble.get_feat(input_val1)
    approx_kernel_mat_ensemble = approx_ensemble.get_kernel_matrix(
        input_val1,
        input_val2,
        quantizer,
        quantizer,
        consistent_quant_seed=True)
    approx_kernel_mat_ensemble = approx_ensemble.get_kernel_matrix(
        input_val1,
        input_val2,
        quantizer,
        quantizer,
        consistent_quant_seed=True)

    print("single learner ensembled nystrom quantizerd version test passed!")
示例#4
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                                             shuffle=False)

    # setup gaussian kernel
    n_input_feat = X_train.shape[1]
    kernel = GaussianKernel(sigma=args.kernel_sigma)
    if args.approx_type == "exact":
        print("exact kernel mode")
        # raise Exception("SGD based exact kernel is not implemented yet!")
        kernel_approx = kernel
        quantizer = None
    elif args.approx_type == "nystrom":
        print("fp nystrom mode")
        kernel_approx = Nystrom(args.n_feat,
                                kernel=kernel,
                                rand_seed=args.random_seed)
        kernel_approx.setup(X_train)
        quantizer = None
    elif args.approx_type == "ensemble_nystrom":
        print("ensembled nystrom mode with ", args.n_ensemble_nystrom,
              "learner")
        kernel_approx = EnsembleNystrom(args.n_feat,
                                        n_learner=args.n_ensemble_nystrom,
                                        kernel=kernel,
                                        rand_seed=args.random_seed)
        kernel_approx.setup(X_train)
        if args.do_fp_feat:
            quantizer = None
        else:
            # decide on the range of representation from training sample based features
            train_feat = kernel_approx.get_feat(X_train)
            min_val = torch.min(train_feat)