Developer Guide for Intel® Data Analytics Acceleration Library 2019 Update 5
Given n feature vectors X = { x 1 = (x 11,..., x 1p ),..., x n = (x n1,...,x np ) } of n p-dimensional feature vectors and a vector of dependent variables y = (y 1,...,y n ), the problem is to build a gradient boosted trees regression model that minimizes the loss function based on the predicted and true value.
Gradient boosted trees regression follows the algorithmic framework of gradient boosted trees training with following loss functions: squared loss
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Given the gradient boosted trees regression model and vectors x 1,...,x r , the problem is to calculate responses for those vectors. To solve the problem for each given feature vector x i , the algorithm finds the leaf node in a tree in the ensemble, and the leaf node gives the tree response. The algorithm result is a sum of responses of all the trees.