Module: Rumale::PairwiseMetric
- Defined in:
- lib/rumale/pairwise_metric.rb
Overview
Module for calculating pairwise distances, similarities, and kernels.
Class Method Summary collapse
-
.euclidean_distance(x, y = nil) ⇒ Numo::DFloat
Calculate the pairwise euclidean distances between x and y.
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.linear_kernel(x, y = nil) ⇒ Numo::DFloat
Calculate the linear kernel between x and y.
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.polynomial_kernel(x, y = nil, degree = 3, gamma = nil, coef = 1) ⇒ Numo::DFloat
Calculate the polynomial kernel between x and y.
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.rbf_kernel(x, y = nil, gamma = nil) ⇒ Numo::DFloat
Calculate the rbf kernel between x and y.
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.sigmoid_kernel(x, y = nil, gamma = nil, coef = 1) ⇒ Numo::DFloat
Calculate the sigmoid kernel between x and y.
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.squared_error(x, y = nil) ⇒ Numo::DFloat
Calculate the pairwise squared errors between x and y.
Class Method Details
.euclidean_distance(x, y = nil) ⇒ Numo::DFloat
Calculate the pairwise euclidean distances between x and y.
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# File 'lib/rumale/pairwise_metric.rb', line 14 def euclidean_distance(x, y = nil) y = x if y.nil? Rumale::Validation.check_sample_array(x) Rumale::Validation.check_sample_array(y) Numo::NMath.sqrt(squared_error(x, y).abs) end |
.linear_kernel(x, y = nil) ⇒ Numo::DFloat
Calculate the linear kernel between x and y.
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# File 'lib/rumale/pairwise_metric.rb', line 63 def linear_kernel(x, y = nil) y = x if y.nil? Rumale::Validation.check_sample_array(x) Rumale::Validation.check_sample_array(y) x.dot(y.transpose) end |
.polynomial_kernel(x, y = nil, degree = 3, gamma = nil, coef = 1) ⇒ Numo::DFloat
Calculate the polynomial kernel between x and y.
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# File 'lib/rumale/pairwise_metric.rb', line 78 def polynomial_kernel(x, y = nil, degree = 3, gamma = nil, coef = 1) y = x if y.nil? gamma ||= 1.0 / x.shape[1] Rumale::Validation.check_sample_array(x) Rumale::Validation.check_sample_array(y) Rumale::Validation.check_params_float(gamma: gamma) Rumale::Validation.check_params_integer(degree: degree, coef: coef) (x.dot(y.transpose) * gamma + coef)**degree end |
.rbf_kernel(x, y = nil, gamma = nil) ⇒ Numo::DFloat
Calculate the rbf kernel between x and y.
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# File 'lib/rumale/pairwise_metric.rb', line 49 def rbf_kernel(x, y = nil, gamma = nil) y = x if y.nil? gamma ||= 1.0 / x.shape[1] Rumale::Validation.check_sample_array(x) Rumale::Validation.check_sample_array(y) Rumale::Validation.check_params_float(gamma: gamma) Numo::NMath.exp(-gamma * squared_error(x, y).abs) end |
.sigmoid_kernel(x, y = nil, gamma = nil, coef = 1) ⇒ Numo::DFloat
Calculate the sigmoid kernel between x and y.
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# File 'lib/rumale/pairwise_metric.rb', line 95 def sigmoid_kernel(x, y = nil, gamma = nil, coef = 1) y = x if y.nil? gamma ||= 1.0 / x.shape[1] Rumale::Validation.check_sample_array(x) Rumale::Validation.check_sample_array(y) Rumale::Validation.check_params_float(gamma: gamma) Rumale::Validation.check_params_integer(coef: coef) Numo::NMath.tanh(x.dot(y.transpose) * gamma + coef) end |
.squared_error(x, y = nil) ⇒ Numo::DFloat
Calculate the pairwise squared errors between x and y.
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# File 'lib/rumale/pairwise_metric.rb', line 26 def squared_error(x, y = nil) y = x if y.nil? Rumale::Validation.check_sample_array(x) Rumale::Validation.check_sample_array(y) # sum_x_vec = (x**2).sum(1) # sum_y_vec = (y**2).sum(1) # dot_xy_mat = x.dot(y.transpose) # dot_xy_mat * -2.0 + sum_x_vec.tile(y.shape[0], 1).transpose + sum_y_vec.tile(x.shape[0], 1) # n_features = x.shape[1] one_vec = Numo::DFloat.ones(n_features).(1) sum_x_vec = (x**2).dot(one_vec) sum_y_vec = (y**2).dot(one_vec).transpose dot_xy_mat = x.dot(y.transpose) dot_xy_mat * -2.0 + sum_x_vec + sum_y_vec end |