bivariate.h

/*
 * Copyright 2026 Daniel Cederberg and William Zhang
 *
 * This file is part of the DNLP-differentiation-engine project.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#ifndef BIVARIATE_H
#define BIVARIATE_H

#include "expr.h"

expr *new_elementwise_mult(expr *left, expr *right);
expr *new_rel_entr_vector_args(expr *left, expr *right);
expr *new_quad_over_lin(expr *left, expr *right);

expr *new_rel_entr_first_arg_scalar(expr *left, expr *right);
expr *new_rel_entr_second_arg_scalar(expr *left, expr *right);

/* Matrix multiplication: Z = X @ Y */
expr *new_matmul(expr *x, expr *y);

/* Left matrix multiplication: A @ f(x) where A is a constant sparse matrix */
expr *new_left_matmul(expr *u, const CSR_Matrix *A);

/* Left matrix multiplication: A @ f(x) where A is a constant dense matrix
 * (row-major, m x n). Uses CBLAS for efficient computation. */
expr *new_left_matmul_dense(expr *u, int m, int n, const double *data);

/* Right matrix multiplication: f(x) @ A where A is a constant matrix */
expr *new_right_matmul(expr *u, const CSR_Matrix *A);

expr *new_right_matmul_dense(expr *u, int m, int n, const double *data);

/* Kronecker product: kron(C, X) where C is a constant sparse matrix and X is
 * an expression of shape (p x q). Output has shape (m*p, n*q). */
expr *new_kron_left(expr *child, const CSR_Matrix *C, int p, int q);

/* Constant scalar multiplication: a * f(x) where a is a constant double */
expr *new_const_scalar_mult(double a, expr *child);

/* Constant vector elementwise multiplication: a ∘ f(x) where a is constant */
expr *new_const_vector_mult(const double *a, expr *child);

#endif /* BIVARIATE_H */