"use strict";
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/**
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* @license
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* Copyright 2018 Google Inc. All Rights Reserved.
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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* =============================================================================
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*/
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Object.defineProperty(exports, "__esModule", { value: true });
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var engine_1 = require("../engine");
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var tensor_util_env_1 = require("../tensor_util_env");
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var util = require("../util");
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var operation_1 = require("./operation");
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var slice_util = require("./slice_util");
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/**
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* Extracts a 1D slice from 1D array starting at coordinates `begin` and is
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* of length `size`. See `slice` for details.
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*/
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function slice1d_(x, begin, size) {
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var $x = tensor_util_env_1.convertToTensor(x, 'x', 'slice1d');
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util.assert($x.rank === 1, function () {
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return "slice1d expects a rank-1 tensor, but got a rank-" + $x.rank + " tensor";
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});
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return exports.slice($x, [begin], [size]);
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}
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/**
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* Extracts a 2D slice from a 2D array starting at coordinates `begin` and
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* is of size `size`. See `slice` for details.
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*/
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function slice2d_(x, begin, size) {
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var $x = tensor_util_env_1.convertToTensor(x, 'x', 'slice2d');
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util.assert($x.rank === 2, function () {
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return "slice2d expects a rank-2 tensor, but got a rank-" + $x.rank + " tensor";
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});
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return exports.slice($x, begin, size);
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}
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/**
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* Extracts a 3D slice from a 3D array starting at coordinates `begin` and
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* is of size `size`. See `slice` for details.
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*/
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function slice3d_(x, begin, size) {
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var $x = tensor_util_env_1.convertToTensor(x, 'x', 'slice3d');
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util.assert($x.rank === 3, function () {
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return "slice3d expects a rank-3 tensor, but got a rank-" + $x.rank + " tensor";
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});
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return exports.slice($x, begin, size);
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}
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/**
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* Extracts a 4D slice from a 4D array starting at coordinates `begin` and
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* is of size `size`. See `slice` for details.
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*/
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function slice4d_(x, begin, size) {
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var $x = tensor_util_env_1.convertToTensor(x, 'x', 'slice4d');
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util.assert($x.rank === 4, function () {
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return "slice4d expects a rank-4 tensor, but got a rank-" + $x.rank + " tensor";
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});
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return exports.slice($x, begin, size);
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}
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/**
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* Extracts a slice from a `tf.Tensor` starting at coordinates `begin`
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* and is of size `size`.
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*
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* Also available are stricter rank-specific methods with the same signature
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* as this method that assert that `x` is of the given rank:
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* - `tf.slice1d`
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* - `tf.slice2d`
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* - `tf.slice3d`
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* - `tf.slice4d`
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*
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* ```js
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* const x = tf.tensor1d([1, 2, 3, 4]);
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*
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* x.slice([1], [2]).print();
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* ```
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*
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* ```js
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* const x = tf.tensor2d([1, 2, 3, 4], [2, 2]);
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*
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* x.slice([1, 0], [1, 2]).print();
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* ```
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* @param x The input `tf.Tensor` to slice from.
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* @param begin The coordinates to start the slice from. The length can be
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* less than the rank of x - the rest of the axes will have implicit 0 as
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* start. Can also be a single number, in which case it specifies the
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* first axis.
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* @param size The size of the slice. The length can be less than the rank of
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* x - the rest of the axes will have implicit -1. A value of -1 requests
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* the rest of the dimensions in the axis. Can also be a single number,
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* in which case it specifies the size of the first axis.
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*/
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/** @doc {heading: 'Tensors', subheading: 'Slicing and Joining'} */
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function slice_(x, begin, size) {
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var $x = tensor_util_env_1.convertToTensor(x, 'x', 'slice');
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if ($x.rank === 0) {
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throw new Error('Slicing scalar is not possible');
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}
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// The following logic allows for more ergonomic calls.
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var begin_;
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if (typeof begin === 'number') {
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begin_ = [begin].concat(new Array($x.rank - 1).fill(0));
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}
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else if (begin.length < $x.rank) {
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begin_ = begin.concat(new Array($x.rank - begin.length).fill(0));
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}
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else {
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begin_ = begin.slice();
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}
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begin_.forEach(function (d) {
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util.assert(d !== -1, function () { return 'slice() does not support negative begin indexing.'; });
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});
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var size_;
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if (size == null) {
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size_ = new Array($x.rank).fill(-1);
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}
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else if (typeof size === 'number') {
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size_ = [size].concat(new Array($x.rank - 1).fill(-1));
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}
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else if (size.length < $x.rank) {
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size_ = size.concat(new Array($x.rank - size.length).fill(-1));
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}
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else {
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size_ = size;
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}
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size_ = size_.map(function (d, i) {
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if (d >= 0) {
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return d;
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}
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else {
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util.assert(d === -1, function () { return "Negative size values should be exactly -1 but got " +
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(d + " for the slice() size at index " + i + "."); });
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return $x.shape[i] - begin_[i];
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}
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});
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slice_util.assertParamsValid($x, begin_, size_);
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var inputShape = $x.shape;
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var grad = function (dy) {
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// Create an Nx2 padding where the first column represents how many
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// zeros are prepended (at start) for each dimension, and the second
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// column indicates how many zeros are appended (at end).
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// The number of zeros to append is the shape of the input
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// elementwise-subtracted by both the begin vector and sizes vector.
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var paddings = [];
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for (var i = 0; i < dy.rank; i++) {
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paddings.push([begin_[i], inputShape[i] - begin_[i] - size_[i]]);
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}
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return { x: function () { return dy.pad(paddings); } };
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};
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var attrs = { begin: begin_, size: size_ };
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return engine_1.ENGINE.runKernelFunc(function (backend) { return backend.slice($x, begin_, size_); }, { x: $x }, grad, 'Slice', attrs);
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}
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exports.slice = operation_1.op({ slice_: slice_ });
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exports.slice1d = operation_1.op({ slice1d_: slice1d_ });
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exports.slice2d = operation_1.op({ slice2d_: slice2d_ });
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exports.slice3d = operation_1.op({ slice3d_: slice3d_ });
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exports.slice4d = operation_1.op({ slice4d_: slice4d_ });
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//# sourceMappingURL=slice.js.map
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