simple-squiggle/node_modules/mathjs/lib/esm/function/matrix/diag.js

164 lines
5.3 KiB
JavaScript

import { isMatrix } from '../../utils/is.js';
import { arraySize } from '../../utils/array.js';
import { isInteger } from '../../utils/number.js';
import { factory } from '../../utils/factory.js';
var name = 'diag';
var dependencies = ['typed', 'matrix', 'DenseMatrix', 'SparseMatrix'];
export var createDiag = /* #__PURE__ */factory(name, dependencies, _ref => {
var {
typed,
matrix,
DenseMatrix,
SparseMatrix
} = _ref;
/**
* Create a diagonal matrix or retrieve the diagonal of a matrix
*
* When `x` is a vector, a matrix with vector `x` on the diagonal will be returned.
* When `x` is a two dimensional matrix, the matrixes `k`th diagonal will be returned as vector.
* When k is positive, the values are placed on the super diagonal.
* When k is negative, the values are placed on the sub diagonal.
*
* Syntax:
*
* math.diag(X)
* math.diag(X, format)
* math.diag(X, k)
* math.diag(X, k, format)
*
* Examples:
*
* // create a diagonal matrix
* math.diag([1, 2, 3]) // returns [[1, 0, 0], [0, 2, 0], [0, 0, 3]]
* math.diag([1, 2, 3], 1) // returns [[0, 1, 0, 0], [0, 0, 2, 0], [0, 0, 0, 3]]
* math.diag([1, 2, 3], -1) // returns [[0, 0, 0], [1, 0, 0], [0, 2, 0], [0, 0, 3]]
*
* // retrieve the diagonal from a matrix
* const a = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
* math.diag(a) // returns [1, 5, 9]
*
* See also:
*
* ones, zeros, identity
*
* @param {Matrix | Array} x A two dimensional matrix or a vector
* @param {number | BigNumber} [k=0] The diagonal where the vector will be filled
* in or retrieved.
* @param {string} [format='dense'] The matrix storage format.
*
* @returns {Matrix | Array} Diagonal matrix from input vector, or diagonal from input matrix.
*/
return typed(name, {
// FIXME: simplify this huge amount of signatures as soon as typed-function supports optional arguments
Array: function Array(x) {
return _diag(x, 0, arraySize(x), null);
},
'Array, number': function ArrayNumber(x, k) {
return _diag(x, k, arraySize(x), null);
},
'Array, BigNumber': function ArrayBigNumber(x, k) {
return _diag(x, k.toNumber(), arraySize(x), null);
},
'Array, string': function ArrayString(x, format) {
return _diag(x, 0, arraySize(x), format);
},
'Array, number, string': function ArrayNumberString(x, k, format) {
return _diag(x, k, arraySize(x), format);
},
'Array, BigNumber, string': function ArrayBigNumberString(x, k, format) {
return _diag(x, k.toNumber(), arraySize(x), format);
},
Matrix: function Matrix(x) {
return _diag(x, 0, x.size(), x.storage());
},
'Matrix, number': function MatrixNumber(x, k) {
return _diag(x, k, x.size(), x.storage());
},
'Matrix, BigNumber': function MatrixBigNumber(x, k) {
return _diag(x, k.toNumber(), x.size(), x.storage());
},
'Matrix, string': function MatrixString(x, format) {
return _diag(x, 0, x.size(), format);
},
'Matrix, number, string': function MatrixNumberString(x, k, format) {
return _diag(x, k, x.size(), format);
},
'Matrix, BigNumber, string': function MatrixBigNumberString(x, k, format) {
return _diag(x, k.toNumber(), x.size(), format);
}
});
/**
* Creeate diagonal matrix from a vector or vice versa
* @param {Array | Matrix} x
* @param {number} k
* @param {string} format Storage format for matrix. If null,
* an Array is returned
* @returns {Array | Matrix}
* @private
*/
function _diag(x, k, size, format) {
if (!isInteger(k)) {
throw new TypeError('Second parameter in function diag must be an integer');
}
var kSuper = k > 0 ? k : 0;
var kSub = k < 0 ? -k : 0; // check dimensions
switch (size.length) {
case 1:
return _createDiagonalMatrix(x, k, format, size[0], kSub, kSuper);
case 2:
return _getDiagonal(x, k, format, size, kSub, kSuper);
}
throw new RangeError('Matrix for function diag must be 2 dimensional');
}
function _createDiagonalMatrix(x, k, format, l, kSub, kSuper) {
// matrix size
var ms = [l + kSub, l + kSuper];
if (format && format !== 'sparse' && format !== 'dense') {
throw new TypeError("Unknown matrix type ".concat(format, "\""));
} // create diagonal matrix
var m = format === 'sparse' ? SparseMatrix.diagonal(ms, x, k) : DenseMatrix.diagonal(ms, x, k); // check we need to return a matrix
return format !== null ? m : m.valueOf();
}
function _getDiagonal(x, k, format, s, kSub, kSuper) {
// check x is a Matrix
if (isMatrix(x)) {
// get diagonal matrix
var dm = x.diagonal(k); // check we need to return a matrix
if (format !== null) {
// check we need to change matrix format
if (format !== dm.storage()) {
return matrix(dm, format);
}
return dm;
}
return dm.valueOf();
} // vector size
var n = Math.min(s[0] - kSub, s[1] - kSuper); // diagonal values
var vector = []; // loop diagonal
for (var i = 0; i < n; i++) {
vector[i] = x[i + kSub][i + kSuper];
} // check we need to return a matrix
return format !== null ? matrix(vector) : vector;
}
});