Questions tagged [random]
This tag is for questions dealing with random numbers, pseudorandom numbers, and computer entropy.
125 questions
6 votes
6 answers
669 views
Do floating point rounding errors affect random number generators
Several random number generators I've used return numbers between 0 and 1, such as JavaScript's Math.random() It's also notoriously true that floating point numbers have an issue with storing specific ...
- 201
1 vote
1 answer
359 views
Random Numbers and Collisions [closed]
I read a question about using a 32bit random number as a "unique" identifier. One of the answers asserted that a "rough guide" to estimating collision likelihood is that there's a ...
- 37
4 votes
4 answers
2k views
Is checking if a new GUID exists before insert a code smell?
Say I use GUIDs as keys. Considering the chance of a duplicate GUID being generated being what they are, is code like this considered a code smell? Guid newID = GenerateGuid(); while (dictionary....
- 1,533
1 vote
2 answers
1k views
What are the reasons not to use random values in unittests? [duplicate]
I've read the questions regarding the use of random values in unit-tests and, well, I still don't quite understand what the argument against random values is. I'm trying to understand because I've had ...
- 346
0 votes
0 answers
340 views
Improving performance of 'Weighted/prioritized left shuffle algorithm'
I wrote a prioritized/weighted left shuffle algorithm (the code is copied from my open source C# project Fluent Random Picker). What does that mean? You've got some values and each of them has a ...
- 101
4 votes
3 answers
1k views
How does cuRAND use a GPU to accelerate random number generation? Don't those require a state?
My understanding is that every PRNG or QRNG requires a state to prevent the next item in its sequence from being too predictable; which is sensible, as they're all running on deterministic hardware. ...
- 396
-1 votes
2 answers
240 views
How random is enough to be random? [closed]
I download the atmospheric noise data from random.org in form: 10111011 01101111 01100001 00001001 00100110 10111011 01110110 11010110 00000111 01111110 10001110 01101010 11100000 11110111 10101011 ...
- 115
-4 votes
1 answer
95 views
How to write a sporadic metronome?
I already asked this question on stackoverflow -- I am posting it here as well, because I think many of you will have encountered an analogous problem. I would appreciate even a link as a reference, ...
1 vote
4 answers
2k views
Is using multiple UUIDs decrease chance of collisions exponentially?
For example if you have a single UUID with a collision probability of x, if you concatenate 2 UUIDs, does the collision probability become x^2? val0 = generate_uuid() val1 = generate_uuid() final_val ...
- 1,980
0 votes
3 answers
1k views
How to guarantee an ID is unique in a non-UUID set of values?
I would like to have IDs of different sizes from the alphabet 0-9. So I have 5-length IDs as in 10000 or 13531, etc.. I have 10, 15, 20, up to 39 digit strings (the size of a UUID). I would like to ...
- 2,787
2 votes
3 answers
951 views
Algorithm for random weighted boolean shuffles?
I don't exactly know how to phrase the thing I'm searching for in a succinct way, which also made it hard to research. In my application I need a random list of booleans, say of length five. The ...
- 139
3 votes
3 answers
600 views
Is it really more difficult to debug randomized algorithms?
I am a theoretical computer scientist. I have heard the following: Practitioners do not like randomized algorithms because they are notoriously difficult to debug. So deterministic algorithms are ...
- 147
0 votes
2 answers
139 views
Is it possible to transfer data with a really unique seed of a psudo random number generator
I have thinking about this idea for over 5 years and i don't have the complete technical knowledge to fully grasp the idea I'm having. The premise of the idea is to have an extremely high base number ...
- 105
0 votes
3 answers
493 views
Getting random yet consistent data for testing
I have a big codebase yet to be covered with tests and rather limited access to the real data. The code that needs to be covered is very data dependent. And the data is anything but shallow and ...
- 441
1 vote
2 answers
1k views
How to shuffle a large data set without touching every row?
Let’s say I have two larges arrays of users with equals number of rows and I want to match them randomly and one to one(one from the first array,one from the second), I will first need to shuffle one ...
- 121