def fit(self, X, y, sample_weight):
        """This method is used to compute A matrix and w based on train dataset"""
        assert len(X) == len(y), "different size of arrays"
        A, w = self.compute_parameters(X, y)
        self.A = sparse.csr_matrix(A)
        self.A_t = sparse.csr_matrix(self.A.transpose())
        self.A_t_sq = self.A_t.multiply(self.A_t)
        self.w = numpy.array(w)
        assert A.shape[0] == len(w), "inconsistent sizes"
        assert A.shape[1] == len(X), "wrong size of matrix"
        self.y_signed = 1 - 2 * y
        return self
dataset/ETHPy150Open anaderi/lhcb_trigger_ml/hep_ml/losses.py/AbstractMatrixLossFunction.fit/swapped operands of `-`