# Tagged Questions

Questions about random number generation and the properties of numbers so generated.

135 views

### Why do I keep getting 0.06 with WorkingPrecision->1?

I'm trying to generate a list of 1000 random numbers with WorkingPrecision->1. Is there any particular reason that I'm getting some entries as 0.06? I have tested the following lines: ...
869 views

### Random Geometric Graphs

I'm trying to implement an application which uses random geometric graphs in Mathematica, but it seems Mathematica lacks the functionality. I need the following functionalities: Generate a set of ...
685 views

### Some questions about random numbers

How can I get non-repeating random numbers from Mathematica 8? How can I know which distribution the numbers I get are? Can I choose the distribution I want together with the non-repeating random ...
1k views

### Wald–Wolfowitz Runs Test

Does Mathematica 8 implement Wald–Wolfowitz runs test for randomness? I can't find it in the documentation. I would like to test some fit residuals.
3k views

### Efficiently generating n-D Gaussian random fields

I am interested in an efficient code to generate an $n$-D Gaussian random field (sometimes called processes in other fields of research), which has applications in cosmology. Attempt I wrote the ...
1k views

### Picking random items out of a list only once

I'm trying to create a function that randomly returns a value from a list but remembers the values that have been given before. At the end when the list is empty it should return an empty list. ...
272 views

### Repeatedly randomly redrawing part of a random sample that matches a certain criterion

I would need some (a lot of) help to improve/rewrite some code. Since my real problem is a bit too complicated to explain, I'll try to show a simplified scheme of what I want to achieve. I create ...
1k views

### Random data generator

Inspired by Quality of random numbers I would like to set up a true random data generator in Mathematica. My idea is to use the static from an open microphone. I recall reading about extracting the "...
3k views

### Quality of random numbers

Mathematica has several ways of generating random numbers: Congruential, ExtendedCA, Legacy, MersenneTwister, MKL, ParallelGenerator, ParallelMersenneTwister, Rule30CA. For ...
381 views

### RandomVariate with a Discrete Distribution

Nature has provided me with a random variable $Z$ taking on the values $0, 1, 2, \ldots$, with probabilities $z_0, z_1, \cdots$. I can sample from the distribution of $Z$ reasonably efficiently (I ...
741 views

### Most efficient way to obtain samples from high-dimensional multivariate distributions?

Is MultinormalDistribution[] efficient and easy to use for high dimensions? I have a variable $n$ representing the dimension of a Monte Carlo integration I do on a ...
583 views

### Going Beyond Pseudorandom Numbers

I cooked up this simple bit of code in hopes to exceed pseudorandom number generation maybe touch the face of true randomization: ...
3k views

### RandomVariate from 2-dimensional probability distribution

A probability distribution can be created in Mathematica (I am using 8.0.1) with e.g. ...
4k views

### Efficient way to generate random points with a predefined lower bound on their pairwise Euclidean distance

Using Mathematica what is an efficient way to generate a list of $n$ random two dimensional points $\{x_i,y_i\}$ where $i=1,...,n$ so that no two points $p_1$ and $p_2$ in the list has an Euclidean ...
394 views

### Are there rules of thumb for knowing when RandomVariate is more efficient than RandomReal?

Please consider the following: From a fresh Mathematica kernel, RandomVariate is more efficient for NormalDistribution but <...
328 views

### How to fix errors in Gram-Schmidt process when using random vectors?

I first make a function to get a random vector on unit sphere in a swath around the equator. That is what the parameter $\gamma$ controls; if $\gamma = 1/2$, the vectors can be chosen anywhere on the ...
623 views

### Generate Random Text within a Rectangle

I would like to generate images such as the four below. That is: some text of different length fit within a Rectangle[] using ...
1k views

### creating vectors with normal distribution of lengths

First consider vectors of unit length, say on the unit sphere. Now I want to give some magnitude to these vectors and I want the magnitude to be chosen from the normal distribution. In one dimension ...
702 views

### Creating randomly oriented planes

I would like to create randomly oriented planes. This is how I'm attempting to do that: I create a 2 random unit vectors, $\mathbf{v}_1$, and $\mathbf{v}_2$, in the $x$-$y$ plane I assume that if I ...
199 views

### Generate a new output using Manipulate

Thanks to methods found in the below, I was able to assemble those elements : Tile image on specific location without space between them How to combine images with the same dimensions in a grid? ...