Refers to the interface of statistics and computing; the use of algorithms and software for statistical purposes.

learn more… | top users | synonyms

0
votes
2answers
23 views

Compare lists of genes

I have two lists of differentially expressed genes: the list 1 was derived from the universe A of total genes while the list 2 was derived from the universe B of total genes. A number of genes is in ...
0
votes
0answers
15 views

Is there any reason that cross correlation would perform well or poorly on sparse binary arrays?

I am using matlabs xcorr to correlate simulated photon count data that has some Gaussian random noise set on top of it and it is working fine when the average value in the arrays is greater than one ...
3
votes
0answers
27 views

Cholesky factorization and forward substitution less accurate than inversion?

I recently asked this question asking for an efficient way to compute the Mahalanobis distance (without calculating the inverse). The accepted solution was to use the Cholesky factorization and ...
2
votes
0answers
21 views

What is a statistically rigorous model? [on hold]

Is there a formal definition for a model or methodology being statistically rigorous? I've seen the term often used in research papers but I've never fully understood what makes the model or method ...
0
votes
0answers
16 views
3
votes
1answer
218 views

Efficient/fast Mahalanobis distance computation

Suppose I have $n$ data points $x_1,\dots,x_n$, each of which is $p$-dimensional. Let $\Sigma$ be the (non-singular) population covariance of these samples. With respect to $\Sigma$, what is the most ...
0
votes
1answer
9 views

Calculation of Cosine Similarity using LSA

I am getting negative cosine similarity value between two documents in Latent Semantic analysis. How should it be treated?
0
votes
0answers
12 views

Can using of Weight function in Latent Semantic Analysis increase the efficiency of the technique?

What type of combination of local & global weight function and what would be the length of the document which can actually increase the efficiency of the LSA.
1
vote
1answer
41 views

How to get corpus used for word-frequencies for languages other than english?

I have taken a corpus of English for finding the word frequency in giving recommendation for spelling mistakes. I just used simple : Edit Distance between ...
1
vote
0answers
30 views

Validating Neural Network

I have a relatively large set of labelled data which I am using to verify how well-trained a neural-network I wrote is. The network uses a competitive learning technique. It has N output neurons, each ...
1
vote
0answers
28 views

Why does the Journal of Statistical Software use The Persistence of Memory as a logo? [closed]

I find this to be pretty interesting, does anyone know why this is?
3
votes
1answer
41 views

Studying complex systems (complexity)

Complex socio-technical systems is one my research interests. Since I plan to further study such systems and related phenomena, I've done a bit of reading and ran across various books, such as Bar-Yam ...
0
votes
0answers
10 views

What does it mean for a function to be “contained in” a confidence band?

So I have this problem that asks me to generate 100 random samples from a standard normal, and I did. It asked me to find a 95% confidence band and I did, using the Python code ...
0
votes
0answers
28 views

Standardization (z-score) across the “Samples” or across the “variables”?

I found in literature that one of the most common way of standardization data is to compute z-scores (mean subtraction and division by standard deviation). Can anybody tell me if it is ok to compute ...
1
vote
1answer
48 views

Computational complexity for linear discriminant analysis

The linear discriminant analysis algorithm is as follows: I want to conduct a computational complexity for it. For each step, the complexity is as follows: For each $c$, there are $N_cd$ ...
0
votes
0answers
25 views

Z-score across the “Samples” or across the “variables”?

I found in literature that one of the most common way of standardization data is to compute z-scores (mean subtraction and division by standard deviation). Can anybody tell me if it is ok to compute ...
-2
votes
1answer
22 views

Why my code error? find call value in R code [closed]

this is my code whats miss? Im confused why my code error please help me this code like black-scholes but in geske formula Values Call = VT1*N(d1)-K2*exp(-r*(T2-T1))*N(d2) N=distribution normal ...
0
votes
1answer
61 views

A Simple Regression Model for Our Experiment? [closed]

We know, In statistics, simple linear regression is the least squares estimator of a linear regression model with a single explanatory variable. In other words, simple linear regression fits a ...
0
votes
1answer
70 views

uniform distribution with density function? [closed]

If $0.3,0.2,0.8,0.3,0.4$‌ are found from one random instance with uniform distribution with following density function, We need to find $\theta $ estimate with Method of moments. how should we do ...
1
vote
1answer
142 views

Do I need to be a mathematician to be more than an expert in machine learning? [closed]

Machine learning has its roots principally in mathematics so if I wanted to be not only an expert but an innovator in this area would I have to be a computer scientist or would I need to be a ...
3
votes
2answers
38 views

Testing if distribution is similar between two groups

I have a variable young that is equal to 1 if a participant is less than 25 years old. I then have a list of of each ...
5
votes
1answer
39 views

Pitfalls in Fitting Nonlinear Models by Transforming to Linearity

Some nonlinear models can be transform to linear models. My understanding is that there might be one-to-one relationship between the estimates of nonlinear model and its linear model form but their ...
0
votes
1answer
29 views

What statistical test to use?

I would like to ask your advice regarding the statistical tools that can be used in analyzing two different kinds of data where I have to determine if there is an association between them. For ...
0
votes
0answers
25 views

divide among the use of statistical software package [duplicate]

Most of the application done by professionals, may it be in finance, economics or other industry is done in either R, SAS or Python. From what it looks like, most of the application in industries in ...
1
vote
0answers
8 views

Confidence Interval for mean difference with non-mutually exclusive 1 to many matches in R

This is somewhat both a programming question, and a stats question. So sorry for the overlap (although it seems that there is a large overlap between the realm of stats and programming of ...
0
votes
0answers
22 views

Model choice for discrete data with R

I'm keen to model the effect (impact) of variable i.e. var1 and its effect (causation inference?) on var2 given the score measure. Sample data (variation of data I have got) ...
7
votes
2answers
1k views

Mathematica's random number generator deviating from binomial probability?

So, let's say you flip a coin 10 times, and call that 1 "event". If you run, 1,000,000 of these "events", what is the proportion of events that have heads between 0.4 and 0.6? Binomial probability ...
0
votes
0answers
38 views

Scoring model/formula to rank based on accuracy of data sources

Let us say i have 5 different data sources. My aim is arrive a score to arrive the accuracy of this data sources. It is like below 1. Refer the section Data confidence calculation in ...
4
votes
1answer
102 views

Estimate mean & standard deviation of set S if I know stats of an inner set and outer set

Suppose I have sets $S_1\subset S_2\subset S_3$. I know exactly the size, mean, and standard deviation of both $S_1$ and $S_3$ and want to estimate the mean and standard deviation of $S_2$, where I ...
0
votes
0answers
33 views

What is first order asymptotic distribution?

I am stuck with this term in a research paper(Hansen, 1999). Its written (p 351) "Hansen (1996) shows that a bootstrap procedure attains the first-order asymptotic distribution, so p-values ...
0
votes
0answers
35 views

What are the quantitative methods alternative to Meta-Analysis?

What are the alternative statistical quantitative synthesis methods for combining studies, if we can't apply meta-analysis because of the heteronegeity or the shape of the data, for the data set of ...
1
vote
2answers
70 views

When is calculating probability based on a poisson distribution preferred over a binomial distribution?

I'm trying to understand why a poisson distribution may be preferred over a binomial one when modeling binary cases. Is there a case where you can't use a binomial distribution to solve a problem ...
3
votes
1answer
86 views

Find the expectation and covariance of a stochastic process

The problem is: Let $W(t)$, $t ≥ 0$, be a standard Wiener process. Define a new stochastic process $Z(t)$ as $Z(t)=e^{W(t)-(1/2)\cdot t}$, $t≥ 0$. Show that $\mathbb{E}[Z(t)] = 1$ and use this result ...
3
votes
2answers
39 views

Hierarchical Gamma-Poisson CDF?

What is the most computationally efficient way to evaluate the CDF $$P(X \leq x | r,v)$$ where $$ X \sim Poisson(\lambda)$$ and $$ \lambda \sim Gamma(r,v)$$ I can't see the next obvious step after ...
0
votes
1answer
66 views

Which statistical melhods could I use to determine if a price is good, based on a history of prices?

I have the following scenario: A history of prices of a specific product; The current price of the same product. The history of prices should contain prices with a certain amount of discount, very ...
5
votes
2answers
88 views

How to validate if a sample is independent and identically distributed

How can I check if the data is drawn i.i.d. from an unknown multivariate distribution?
0
votes
1answer
55 views

Similarity scoring to compare multi-dimensional datasets

I am trying to come up with a mechanism of scoring a set of multidimensional datasets based on a similarity with an ideal dataset. Each dataset will all have the same dimensions along with the ideal. ...
1
vote
0answers
88 views

R - system is computationally singular - dealing with small numbers

I'm working with a ~200x200 Markovian transition matrix of non-zero probabilities. Forcibly, these probabilities are, for the large part, going to be very small. I am trying to find the inverse of my ...
0
votes
0answers
12 views

Can one fuse graphical and quantitative techniques?

The NIST Engineering Statistics Handbook provides a great compendium of graphical and quantitative techniques. Every technique (graphical or quantitative) is usually explained with a set a questions. ...
3
votes
1answer
26 views

Data rescaling for a more informative heatmap?

I have a 2000$\times$2000 matrix of values. Over half of the values are 0, and for those non-zeros, most of them are less than 10, but the maximum value is 140. So when I do a heatmap, it looks like ...
1
vote
0answers
32 views

propagation of the error in the summation

I have a question regarding the propagation of the error during the summation. Please see the equation below. In this equation only quantity R has an error. How it will propagate to the final value ...
2
votes
1answer
44 views

What is the distribution of $X$ since $X|Y \sim \mathrm{Bi}(Y, p)$ and $Y \sim \mathrm{NB}(r, q)$?

I have done the usual steps to calculate the marginal distribution of $X$, i.e. using the following formula: $$p(X) = \int p(X,Y) dY = \int p(X|Y) p(Y) dY$$ Therefore, it holds: \begin{align} P(X=k) ...
0
votes
0answers
5 views

For an ANOVA comparing here treatment condition

a) None of these choices is correct. b) All three of the population means are different from each other. c) At least one of the three population means is different from another mean. d) There are no ...
0
votes
0answers
33 views

Convergence Time of the EM Algorithm Depending on the Inital Parameter Values

I try to get an intuitive understanding of the convergence properties of the EM-Algorithm. I wrote a code that does the following experiment. We are given three coins: $H$, $A$ and $B$; with ...
1
vote
1answer
41 views

measure for jobs/complaints ratio

I have a number of jobs in a database which can receive complaints. A job can receive several complaints and a job has an associated supplier. I would like to identify the worst performing suppliers. ...
0
votes
0answers
25 views

selection of features with Weka

I have a question and I hope that you can help me: I have a bilingual text(source language and target language). I extract from this text the best source phrase and the target phrase related to this ...
0
votes
0answers
174 views

Is it correct or not I applied PERMANOVA-test and interpreted results?

I want to associate nutrients with microbiota bacteria composition. My data consist of two tables: nutrient table (row - patients, column - some of nutrients, e.g. protein, calorage); bacterial ...
2
votes
0answers
30 views

Sampling Size for a large Dataset

I am having a dataset of size upwards of 200 million rows. I have no knowledge of the distribution of this dataset. Would like to perform some analysis on this - like look at the ...
1
vote
0answers
25 views

What statistical analysis to use?

What statistical analysis should I use if I have 2 groups of subjects (high and low comprehenders) which are divided into 3 subgroups according to text genre (poetry, short story, drama) and subjected ...
2
votes
1answer
211 views

Area within a given number of standard deviations from given mean

I have a variable with mean value of 18.85 and standard deviation of 1.45. I want to define the area that is covered by 1.45 standard deviations left and 1.45 standard deviations on the right side ...