I understand how standard random number generators work. But when working with crytpography, the random numbers really have to be random. I know there are instruments that read cosmic white noise to help generate secure hashes, but your standard PC doesn't have this. How does a cryptographically secure random number generator get it...
Is there any good open-source implementation of Mersenne Twister and other good random number generators in Python available? I would like to use in for teaching math and comp sci majors? I am also looking for the corresponding theoretical support. Edit: Source code of Mersenne Twister is readily available in various languages such as ...
I'm looking for a very quick way to generate an alphanumeric unique id for a primary key in a table. Would something like this work? def genKey(): hash = hashlib.md5(RANDOM_NUMBER).digest().encode("base64") alnum_hash = re.sub(r'[^a-zA-Z0-9]', "", hash) return alnum_hash[:16] What would be a good way to generate random nu...
Hello, I'm trying to use the Gamma distribution from boost::math but it looks like it isn't possible to use it with boost::variate_generator. Could someone confirm that? Or is there a way to use it. I discovered that there is a boost::gamma_distribution undocumented that could probably be used too but it only allows to choose the alpha...
how would you use, say, the string "abc" as the seed of an rng? would you change it into 0x616263, or 123, or hash it with sha1 (or some other hash), or something else? ...
I am putting together an internal "every developer should know" wiki page. I saw many discussions regarding rand() % N, but not a single web page that explains it all. For instance, I am curious if this problem is only C- and Linux-specific, or if it also applies to Windows, C++,. Java, .Net, Python, Perl. Please help me get to the bo...
Hi everyone, I'm using a custom random number function rand48 in CUDA. The function does not allow an upperbound to be set, but I require the output to be between 0 and 1. I guess I'm missing something but how would I convert the output to be between 0 and 1, the length of the number can change e.g. 697135872 would need to be divided ...
I've been given the task of porting Java's Java.util.Random() to JavaScript, and I've run across a huge performance hit/inaccuracy using bitwise operators in Javascript on sufficiently large numbers. Some cursory research states that "bitwise operators in JavaScript are inherently slow," because internally it appears that JavaScript will...
What are some alternative methods to generate 1000 distinct random integers in the range [0,8000] as opposed to the following: naive method: generating a number and checking if it's already in the array. O(n^2) linear shuffle: generate sequence 0 to 8000, shuffle, take the first 1000. O(n) ...
For a simple simulation in C, I need to generate exponential random variables. I remember reading somewhere (but I can't find it now, and I don't remember why) that using the rand() function to generate random integers in a fixed range would generate non-uniformly distributed integers. Because of this, I'm wondering if this code might ha...
Most of us know that the command random.randint(1,n) in Python (2.X.X) would generate a number in random (pseudo-random) between 1 and n. I am interested in knowing what is the upper limit for n ? ...
to retrieve k random numbers from an array of undetermined size we use a technique called reservoir sampling. Can anybody briefly highlight how it happens with a sample code?? ...
how does one use code to do this: produce 15 random numbers [EDIT: from 1 - 15] that are not in any order, and that only occur once eg. 1 4, 2, 5, 3, 6, 8, 7, 9, 10, 13, 12, 15, 14, 11 rand() or arc4rand() can repeat some, which is not what im after. Thanks ...
I have a problem where depending on the result of a random coin flip, I have to sample a random starting position from a string. If the sampling of this random position is uniform over the string, I thought of two approaches to do it: one using multinomial from numpy.random, the other using the simple randint function of Python standard...
Can anyone recommend a cryptographically-secure pseudo random number generator library for Delphi (Win32)? Can be free or commercial, but will ideally be an active project. I'd like it to include source code. ...
Possible Duplicates: Auto Generated Avatars on Stack Overflow what is the algorithm used to generate those little gravatar identicon images? StackOverflow seems to have nice, randomly generated avatars for default users. How do I do that (preferably with PHP)? ...
Brand new to droid programming, but would love to learn as much as possible, so I finally got my emulator working correctly, I even got a hello world button to work, I'm attempting to make this button display a random number, I've googled this and came up with this code: Random generator = new Random(); int n = generator.nextInt(n); ...
Hi all, As all developers do, we constantly deal with some kind of identifiers as part of our daily work. Most of the time, it's about bugs or support tickets. Our software, upon detecting a bug, creates a package that has a name formatted from a timestamp and a version number, which is a cheap way of creating reasonably unique identifi...
rand(1,N) but excluding array(a,b,c,..), is there already a built-in function that I don't know or do I have to implement it myself(how?) ? UPDATE The qualified solution should have gold performance whether the size of the excluded array is big or not. ...
I am using below code to generate random numbers in range... int randomNumberWithinRange(int min,int max) { int snowSize = 0; do { snowSize = rand()%max; } while( snowSize < min || snowSize > max ); return snowSize; } for(int i = 0; i < 10 ; i++) NSlog("@"%d",\t", rando...