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19 views

What could cause unreproducible neural network training performance?

I'm trying to select various hyper-parameters, especially hidden layer sizes and depth, for my back-propagation ReLU neural network. I define a procedure to train/test a given configuration by ...
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0answers
16 views

Wald–Wolfowitz runs test

How does the formula of mean and variance of Run test come ? That is , How to derive those formula ?
5
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1answer
206 views

Is tossing a coin a fair way of randomising a group into two groups?

So myself and my uncle are having an argument over whether a coin flip is truly random. I argue it isn't because in real terms a coin tosser will always manipulate a coin so the result isnt 50/50 ...
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0answers
21 views

Intuition behind Whites reality check

Assume you mined some strategy following a simple rule based approach with positive performance measures over the last 30 years from a giant parameter space. Now you want to find out how likely it is ...
1
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1answer
51 views

Can a truly randomized procedure (e.g. random treatment allocation) result in unbalanced distributions?

Thousands of randomized trials are ongoing or in the planning. These trials rely on randomization procedures (e.g. patients being randomized to either placebo or active drugs) to yield two balanced ...
1
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1answer
21 views

how a random sample differ from the whole population in confidence interval?

I know what confidence interval mean in random sampling, but I'm confused what does CI mean in the whole population. Is there any difference? Or I could see the whole population as a "big" random ...
4
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1answer
52 views

One sample run test, but with P(+) $\neq \frac{_1}{^2}$

I am trying to find out how to conduct run tests on one sample but with a non 0.5-0.5 underlying occurrence pattern of the two dichotomous values. For instance ...
2
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1answer
48 views

Is there any difference between Random and Probabilistic?

It seems i can't directly say probabilistic and random are identical . But this is telling : random experiment is a probabilistic experiment. Is there any difference between Random and ...
0
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0answers
33 views

Suggested algorithms for time series analysis of sporadic events

I have a series of sporadic, discrete time series events that appear to occur in shorter interval clusters and I am looking for a way to determine the frequencies at which the events occur. None of ...
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0answers
29 views

Non Probability Analysis

I want to quantify the results of my non-probability survey. Are there any analysis techniques I can use that don't require or assume randomness other than descriptive?
1
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0answers
48 views

Accounting for measurement bias using a histogram or violin plot and numerical data in R

The Problem I have a gardener whose job it is to measure trees in meters using a measuring stick. She measures the heights of 1,000 trees. I plot these measurements on a violin plot in R. I am ...
2
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0answers
33 views

Auto-Correlation

I had thought that if I call acf() on a vector of integers, and examine the value correlation coefficient at K (lag) = 1, I would expect: A value close to +/-1 would show that the integers are not ...
0
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0answers
59 views

Deterministic Model and Stochastic Model

Deterministic model involves no randomness, where as stochastic model involves randomness. An example of deterministic model is: return of $5$years of investment with an annual interest of $7$% . An ...
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1answer
132 views

Is a neural network the only way to learn input/output relation?

first question here but hopefully you can help. Firstly I'm a web programmer by trade but I've touched a bit of neural networks in my university days. I've got a project to do with predicting the ...
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1answer
37 views

Collective randomness of data generated using different seeds

We are generating 5 random numbers for every object we process - this is Java, but the code is pretty easy to follow (docs): ...
1
vote
1answer
60 views

How to predict the time series data

I have no background of advanced stats. I am an engineer and I have the following data. I am representing it as a decent graph for better understanding. I want to forecast the collision for the next ...
1
vote
1answer
35 views

Is it possible for two independent people to generate randomness?

It is well documented that people are not very good at generating random sequences. However, is it possible that two people, working independently, could generate randomness together? Consider the ...
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0answers
6 views

How many bags of Lego minifigs do I need to buy to complete a set? [duplicate]

Lego sells minifigs. They release these as "series". Series 11 has 16 different figures to collect. Each packet is sealed and opaque. You do not know which figure is in the pack when you buy it. ...
1
vote
1answer
166 views

Multilevel: Can I include two dummy variables of a 7-dummy-set into a random slope?

I am calculating a two-level linear multilevel analysis. A look at the random intercept random slope model showed me a significant decrease in my model deviance if I include two dummy variables. Those ...
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0answers
45 views

How can I model this problem?

Genetic algorithms are a kind of evolutive approach to problem solving where solutions are randomly generated and crossed with each other as to produce other solutions. With each generation or ...
0
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0answers
19 views

The outlier in non-random data

I have tested a time series data by using Run Test. The result shows that it is non random. How could I detect which data point(s) caused that non-randomness? Is there have any methods I can use? ...
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0answers
30 views

Testing for consistency in survey data

I have a panel of 6 persons which each have generated 2 recipes (cooking), R1 and R2. I have then asked everyone in the panel to ...
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0answers
67 views

What kinds of PRNG exist outside Linear congruential generators?

I'm kinda running out of words, Linear congruential generator are really low quality PRNG but it was all I needed for some basic stuff, now I need to fill the blank and get to know other families of ...
1
vote
4answers
81 views

Are integer results from random number generators unlikely?

If I generate a random float value between 0…1, say to 40 digits, or n digits, aren't the chances of getting a true zero (0) or a true one (1) incredibly small? On the zero condition, every 0–9 digit ...
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3answers
80 views

Check if a certain procedure is random or not

I am not a statistician, but I have a personal project and I need a help. I will simplify the project a lot to make it more clear and easier to understand. Then in base of your answers, I can fit it ...
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3answers
2k views

Is it a truly random sample?

Any hints on how to solve this problem? A sample of 400 items is taken from a normal population whose mean as well as variance is 4. If the sample mean is 4.5, can the sample be regarded as a ...
1
vote
2answers
135 views

Does randomness imply independence?

By looking at a lag plot, it seems that my dataset is random (no autocorrelation whatsoever). Should this be sufficient to infer independence of observations? As a matter of fact, I know that the ...
0
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0answers
26 views

How to test a Random Number generator in R? [duplicate]

I have a random number generator of U(0,1), I apply the ks test on x, which has 10000 random numbers in [0,1]: > ks.test(x,"punif") and obtain this result: ...
2
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0answers
192 views

Precision and recall of a random classifier

My understanding of precision and recall tells me that there is a tradeoff between these two measures: you can improve one at the cost of the other. However, when I think of a random classifier (on a ...
0
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1answer
18 views

I have a source of numbers. Is there a way to estimate the probability for the given number to originate from it?

The source in question is some blackbox which output looks completely random to me, yey I haven't tested if for randomness quality. I don't exactly know insides of blackbox but can easily caputure it ...
7
votes
1answer
310 views

Probability to draw a black ball in a set of black and white balls with mixed replacement conditions

When a black ball is drawn, it is not replaced in the set, but white balls are replaced. I have thought of this, with the notations: $b$, $w$ the initial number of black and white balls $x_i = (b ...
1
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1answer
55 views

Quality of randomness in generated random number

I have generated a list of 3 random number where each summed to 1. I would like to access the quality of randomness. What is the best mechanism to access this randomness? E.g my random numbers are. ...
7
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2answers
536 views

How to generate random points in the volume of a sphere with uniform nearest neighbour distances

With respect to post (1) and post (2), I generated a large number of uniformly distributed points inside the ball of radius $R$ using $\frac{R_s U^{1/3}}{\sqrt{X_1^2 + X_2^2 + X_3^2}} (X_1, X_2, ...
1
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0answers
25 views

Modeling a list with a tunable degree of disorder/shuffling

Imagine we have a list of ordered numbers $L = (1, 2,\dots, N)$. I want to add an arbitrary amount of "disorder" to that list. For instance: Adding a little bit of disorder would permute a few ...
2
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0answers
105 views

What is the distribution of an outer product of random values mod P?

I haven't been able to answer this daunting question for days now and I am not able to find the right resource for it, so maybe someone here might help me out. Consider an outer product of two ...
1
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0answers
65 views

How to test the randomness of a sequence of real m-tuples?

1) Let $\{a_i\}_{i = 1, ...,n}$ be a real sequence generated by a pseudorandom number generator. How can I check the randomness of such real numbers using, for instance, Runs test? 2) Assume three ...
2
votes
1answer
418 views

Wilcoxon signed rank test on anonymous sample

I carried out a test on a group of 100 people. The test contained 10 questions with 5-point Likert scale answers (1 = Strongly Agree, 5 = Strongly Disagree). After the test was conducted, the group ...
1
vote
1answer
658 views

NIST randomness test fails in random generated bits

I am using the NIST randomness test suite which checks whether a bit sequence is random over 15 different tests. I have problems in verifying if this suite works fine. The situation is that if I ...
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0answers
43 views

Finding a sample to represent a known population

Entire Population: 30,000 Known properties of population: Age, gender, height, weight, Ideal representative sample size: ??? This is for a mailing list test group selection. Problem constraints: ...
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1answer
1k views

Best way to test runs

I have the following sample: ...
0
votes
1answer
138 views

How exactly does the R random number generator work? [closed]

When I generate a random number using the following procedure: set.seed(123) rnorm(1) I would like to know what exactly is happening in this case? Is R reading ...
3
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0answers
34 views

How to check if a data sequence is really random? [duplicate]

I wonder how can I test if a data sequence is really random? Of course I can randomly cut it into equal pieces, and check if the correlation coefficient between different pieces on average is zero. ...
2
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0answers
48 views

How to select model when different models are preferred with different seeds?

I am trying to apply the lasso or ridge regression to my data set for the feature selection, but different random seeds produce different models. What is a good or universal way to obtain the final ...
2
votes
1answer
59 views

Filtering random guessers from daily surveys

Assume we're polling or surveying people about their predictions regarding some future event. This survey is done every day, and the event they are asked to predict is the same every time. For ...
0
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0answers
1k views

Easy-to-apply tests for randomness

I'm interested in testing a sequence of numbers for randomness. I've done some searching and come across die hard and die harder. However these tests seem to require some expertise to apply, or at ...
4
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0answers
97 views

Sanity check to determine if 'random' data on disk drive may have been tampered with

I've got some code that does a Dept of Defense secure erase of disks, and would like to know about a good sanity check to run after the fact. Bottom line, the last write phase of a secure erase of a ...
2
votes
2answers
286 views

Best process for randomly drawing an odd and an even number

I want to draw a random number from 1 to 100. If this number is even, I want to then draw a random number from the odd numbers between 1 and 100. If the first number is odd, I want to draw a random ...
1
vote
1answer
79 views

Detecting/analyzing non-random permutations of a random sequence

I am looking for theoretical results regarding how easy it is to detect alteration of a random sequence. The permutation I am most interested in is where a subsequence of the random numbers is ...
1
vote
1answer
62 views

randomness and computers

How do computers achieve randomness if they really do ? How to decide whether something is random or not? Is there a measure of randomness? ...
8
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1answer
611 views

Differential Entropy

Differential entropy of Gaussian R.V. is $\log_2(\sigma \sqrt{2\pi e})$. This is dependent on $\sigma$, which is the standard deviation. If we normalize the random variable so that it has unit ...