Can Python’s set absence of ordering be considered random order?
No, it is not random. It is “arbitrarily ordered”, which means that you cannot depend on it being either ordered or random.
shuffle
Maximal Length of List to Shuffle with Python random.shuffle?
TL;DR: It “breaks” on lists with over 2080 elements, but don’t worry too much 🙂 Complete answer: First of all, notice that “shuffling” a list can be understood (conceptually) as generating all possible permutations of the elements of the lists, and picking one of these permutations at random. Then, you must remember that all self-contained … Read more
Shuffles Random Numbers with no repetition in Javascript/PHP
Try this, $count = 15; $values = range(1, $count); shuffle($values); $values = array_slice($values, 0, 15); OR $numbers = array(); do { $possible = rand(1,15); if (!isset($numbers[$possible])) { $numbers[$possible] = true; } } while (count($numbers) < 15); print_r(array_keys($numbers)); may this help you.
How to make sure that std::random_shuffle always produces a different result?
std::random_shuffle has two forms. One that takes 2 arguments (begin/end iterators), and one that takes 3 (begin/end iterator and a random generator). The first form uses std::rand(), so you would use std::srand() to seed it’s random number generator. You can also use the 3-argument version and provide the RNG yourself.
Numpy shuffle multidimensional array by row only, keep column order unchanged
You can use numpy.random.shuffle(). This function only shuffles the array along the first axis of a multi-dimensional array. The order of sub-arrays is changed but their contents remains the same. In [2]: import numpy as np In [3]: In [3]: X = np.random.random((6, 2)) In [4]: X Out[4]: array([[0.71935047, 0.25796155], [0.4621708 , 0.55140423], [0.22605866, 0.61581771], … Read more
Efficient sse shuffle mask generation for left-packing byte elements
Assuming: change1 = _mm_movemask_epi8(bytemask); offset = popcnt(change1); On large buffers, using two shuffles and a 1 KiB table is only ~10% slower than using 1 shuffle and a 1MiB table. My attempts at generating the shuffle mask via prefix sums and bit twiddling are about about half the speed of the table based methods (solutions … Read more
shuffle array in ng-repeat angular
Thx to http://bost.ocks.org/mike/shuffle/ use this shuffling function: Speciality with it is, that the input array stays bindable because the shuffling wont create a new array but instead does the shuffling on the same reference. // -> Fisher–Yates shuffle algorithm var shuffleArray = function(array) { var m = array.length, t, i; // While there remain elements … Read more
Randomizing elements in an array?
I wrote this a while ago and it so happens to fit what you’re looking for. I believe it’s the Fisher-Yates shuffle that ojblass refers to: Array.prototype.shuffle = function() { var i = this.length; while (–i) { var j = Math.floor(Math.random() * (i + 1)) var temp = this[i]; this[i] = this[j]; this[j] = temp; … Read more
Python – shuffle only some elements of a list
What you do is this: copy = list[2:] random.shuffle(copy) which does not do much to the original list. Try this: copy = list[2:] random.shuffle(copy) list[2:] = copy # overwrite the original
How random is PHP’s shuffle function?
shuffle() function is based on the same generator as rand(), which is the system generator based on linear congruential algorithm. This is a fast generator, but with more or less randomness. Since PHP 4.2.0, the random generator is seeded automatically, but you can use srand() function to seed it if you want. mtrand() is based … Read more