@tensorflow/tfjs-core/dist/backends/einsum_util.d.ts

Hardware-accelerated JavaScript library for machine intelligence

/**
 * @license
 * Copyright 2021 Google LLC. All Rights Reserved.
 * 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.
 * =============================================================================
 */
/// <amd-module name="@tensorflow/tfjs-core/dist/backends/einsum_util" />
/**
 * Utility functions for computing einsum (tensor contraction and summation
 * based on Einstein summation.)
 */
import { Tensor } from '../tensor';
/**
 * Parse an equation for einsum.
 *
 * @param equation The einsum equation (e.g., "ij,jk->ik").
 * @param numTensors Number of tensors provided along with `equation`. Used to
 *   check matching number of input tensors.
 * @returns An object consisting of the following fields:
 *   - allDims: all dimension names as strings.
 *   - summedDims: a list of all dimensions being summed over, as indices to
 *     the elements of `allDims`.
 *   - idDims: indices of the dimensions in each input tensor, as indices to
 *     the elements of `allDims.
 */
export declare function decodeEinsumEquation(equation: string, numTensors: number): {
    allDims: string[];
    summedDims: number[];
    idDims: number[][];
};
/**
 * Get the permutation for a given input tensor.
 *
 * @param nDims Total number of dimension of all tensors involved in the einsum
 *   operation.
 * @param idDims Dimension indices involve in the tensor in question.
 * @returns An object consisting of the following fields:
 *   - permutationIndices: Indices to permute the axes of the tensor with.
 *   - expandDims: Indices to the dimension that need to be expanded from the
 *     tensor after permutation.
 */
export declare function getEinsumPermutation(nDims: number, idDims: number[]): {
    permutationIndices: number[];
    expandDims: number[];
};
/**
 * Checks that the dimension sizes from different input tensors match the
 * equation.
 */
export declare function checkEinsumDimSizes(nDims: number, idDims: number[][], tensors: Tensor[]): void;
/**
 * Gets path of computation for einsum.
 *
 * @param summedDims indices to the dimensions being summed over.
 * @param idDims A look up table for the dimensions present in each input
 *     tensor.Each constituent array contains indices for the dimensions in the
 *     corresponding input tensor.
 *
 * @return A map with two fields:
 *   - path: The path of computation, with each element indicating the dimension
 *     being summed over after the element-wise multiplication in that step.
 *   - steps: With the same length as `path`. Each element contains the indices
 *     to the input tensors being used for element-wise multiplication in the
 *     corresponding step.
 */
export declare function getEinsumComputePath(summedDims: number[], idDims: number[][]): {
    path: number[];
    steps: number[][];
};
/** Determines if an axes permutation is the identity permutation. */
export declare function isIdentityPermutation(perm: number[]): boolean;