feat:node-modules

node_modules/mathjs/lib/esm/function/probability/permutations.js

@@ -0,0 +1,78 @@
+import { isInteger } from '../../utils/number.js';
+import { product } from '../../utils/product.js';
+import { factory } from '../../utils/factory.js';
+var name = 'permutations';
+var dependencies = ['typed', 'factorial'];
+export var createPermutations = /* #__PURE__ */factory(name, dependencies, _ref => {
+  var {
+    typed,
+    factorial
+  } = _ref;
+  /**
+   * Compute the number of ways of obtaining an ordered subset of `k` elements
+   * from a set of `n` elements.
+   *
+   * Permutations only takes integer arguments.
+   * The following condition must be enforced: k <= n.
+   *
+   * Syntax:
+   *
+   *     math.permutations(n)
+   *     math.permutations(n, k)
+   *
+   * Examples:
+   *
+   *    math.permutations(5)     // 120
+   *    math.permutations(5, 3)  // 60
+   *
+   * See also:
+   *
+   *    combinations, combinationsWithRep, factorial
+   *
+   * @param {number | BigNumber} n   The number of objects in total
+   * @param {number | BigNumber} [k] The number of objects in the subset
+   * @return {number | BigNumber}    The number of permutations
+   */
+  return typed(name, {
+    'number | BigNumber': factorial,
+    'number, number': function number_number(n, k) {
+      if (!isInteger(n) || n < 0) {
+        throw new TypeError('Positive integer value expected in function permutations');
+      }
+      if (!isInteger(k) || k < 0) {
+        throw new TypeError('Positive integer value expected in function permutations');
+      }
+      if (k > n) {
+        throw new TypeError('second argument k must be less than or equal to first argument n');
+      }
+      // Permute n objects, k at a time
+      return product(n - k + 1, n);
+    },
+    'BigNumber, BigNumber': function BigNumber_BigNumber(n, k) {
+      var result, i;
+      if (!isPositiveInteger(n) || !isPositiveInteger(k)) {
+        throw new TypeError('Positive integer value expected in function permutations');
+      }
+      if (k.gt(n)) {
+        throw new TypeError('second argument k must be less than or equal to first argument n');
+      }
+      var one = n.mul(0).add(1);
+      result = one;
+      for (i = n.minus(k).plus(1); i.lte(n); i = i.plus(1)) {
+        result = result.times(i);
+      }
+      return result;
+    }
+
+    // TODO: implement support for collection in permutations
+  });
+});
+
+/**
+ * Test whether BigNumber n is a positive integer
+ * @param {BigNumber} n
+ * @returns {boolean} isPositiveInteger
+ */
+function isPositiveInteger(n) {
+  return n.isInteger() && n.gte(0);
+}