Questions on the statistical functions of Mathematica.

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7
votes
1answer
199 views

How does LocationTest choose its “AutomaticTest”?

Is there a way of determining how LocationTest chooses its "AutomaticTest"? Sometimes it's clear from the ...
7
votes
1answer
712 views

Grain(Particle) Size Distribution (PSD) Analysis with Mathematica

I would like to do an analysis of the grain size distribution of a Monte Carlo Grain Growth simulation I implemented based on the nice example by Rituraj Nandan (see Link). The result of this ...
6
votes
2answers
270 views

BoxWhiskerChart with logarithmic axes

I would like to make a following chart Ideally I would also like to control the boxes position on a logarithmic x-axis. Some inspiration how to do the latter may be found in the answer to my ...
6
votes
2answers
2k views

Function to compute the probability of exactly one event occurring out of N independent events

Is there a built in function (or a function in one of the standard packages) that allows you to compute the probability of exactly one event occurring out of some known set of probabilities for N ...
6
votes
3answers
350 views

Calculate probability function

I would like to calculate the following with Mathematica: Let $X$ be a random variable with probability function $$p(x)= \left\{ \begin{matrix} \frac{x}{6} & \text{for }x \in \{1,2,3\}\\ 0 ...
6
votes
1answer
193 views

Obtaining standardised regression coeffiecients

Regression coefficients are the constant that indicate the rate of change in one variable as a function of change in another. Standardised regression coefficients are the same, but refer to a change ...
6
votes
1answer
400 views

How do I calculate Standard Deviation confidence intervals in Mathematica?

I have a series of simulation results and I would like to demonstrate how the confidence interval for the mean and standard deviation decrease as the number of results increases. I have done this for ...
6
votes
1answer
288 views

Inconsistency in Histogram's “Probability” Binsize

Context Let me define a Probability distribution (following the documentation and with some connection to this question) ...
6
votes
1answer
93 views

Better way to get Fisher Exact?

I want to perform a Pearson's $\chi^2$ test to analyse contingency tables; but because I have small numbers, it is recommended to perform instead what is called a Fisher's Exact Test. This requires ...
6
votes
2answers
97 views

Best way to represent a joint distribution

The motivation for this question is producing a distribution that produces the gender and age of an individual when the distribution of ages depends on gender. Suppose I want a distribution which, ...
6
votes
2answers
644 views

How can I compute and plot the 95% confidence bands for a fitted logistic regression model?

I have a set of binary data that I' d like to fit a logistic regression model to and show the 95% confidence band around the fitted function. I can produce the regression model but how do I compute ...
6
votes
1answer
297 views

Fix end point in smooth kernel distribution density

I am using some extreme value fitting method which results in a parametric distribution for values exceeding some threshold, all values $\geq 0$. For smaller values I'd like to use a smooth kernel ...
6
votes
1answer
253 views

WinBUGS Interface

Has anyone created on WinBUGS (Bayesian inference Using Gibbs Sampling) interface with Mathematica similar to BugsXLA for Excel? I'd like to setup the model, define the evidence in a notebook and then ...
6
votes
1answer
296 views

Support for Multidimensional Scaling (MDS)?

Does mathematica support MDS? Or, are there any libraries that support it? Basically, I have points and a distance function defined between them, and I want to plot them in 2D space, trying to ...
6
votes
0answers
343 views

Sensitivity Analysis: Global Sensitivity and Screening

I have a model which accepts several input parameters and now I want to study the sensitivity to certain parameters as described in here: Cross Validated Answer and in Wikipedia. There is also a link ...
5
votes
3answers
414 views

Creating word histograms from lists of strings

Consider the following: ...
5
votes
2answers
458 views

Plotting 2D Data with Categorical Data in One of the Dimensions

I have a 2D data set in the form of: data={{Category, Integer}, {Category, Integer},{Category, Integer}...} It is a pretty simple data set with four categories ...
5
votes
1answer
385 views

Hodrick–Prescott filter (one-sided version)

I am interested in implementing Hodrick–Prescott filter (HP filter) on my time series data in Mathematica. I know that there is already a version of two-sided original filter for Mathematica (see ...
5
votes
4answers
397 views

Identifying subsets with minimal standard deviation

Consider the following: ...
5
votes
1answer
140 views

Reverse engineer a sample value from a CDF

The image below shows the cumulative distribution of a normal distribution with mean = 4 and standard deviation = 1. Notice that if you have a value with a rank of 0.8 (meaning it would be 80th item ...
5
votes
1answer
422 views

Multinomial logistic regression

Has anyone done multinomial logistic regression in Mathematica? The binomial case is essentially done on the LogitModelFit documentation page and works fine. I am ...
5
votes
1answer
175 views

Representative Smooth Kernel Distribution from Truncated Distribution

I am trying to produce a better distribution from a dataset that is bounded to be greater than 0. Here is an example distribution from the documentation that mimics the behavior of the actual dataset: ...
5
votes
1answer
104 views

PearsonChiSquareTest: set degrees of freedom

How to set degrees of freedom for PearsonChiSquareTest? I have this: ...
5
votes
0answers
95 views

Estimation of vector autoregressive (VAR) process

To estimate 1-dimensional VAR process (which is AR process) you can easily use functions EstimatedProcess or ...
4
votes
4answers
2k views

Function for Autocorrelation

Is there a built in function to compute the autocorrelation of a signal ?
4
votes
2answers
196 views

How to find the variance under the assumption that x follows some probability distribution

I am aware that we can find the expectation under the assumption that x follows some probability distribution, something like this: ...
4
votes
3answers
528 views

BoxWhiskerPlot - how to specify boxes position on the horizontal axis

Let's say I have a folowing set of data: k = 1 : list of values k = 3 : list of values k = 10 : list of values I know that to make a BoxWhiskerChart I have to ...
4
votes
2answers
542 views

How to solve for an Z-Score of a T-Distribution?

I'm looking for the Z-Score for a distribution, where the integrated area sums up to 0.90. Unfortunately I always get an error from Mathematica, ...
4
votes
2answers
2k views

How to use a 3×3 covariance matrix to plot an error ellipsoid?

I have a 3×3 error covariance in Mathematica, but I don't know how to use it for plotting the error ellipsoid. It would be great if you can show me how I can do that for the below covariance matrix: ...
4
votes
2answers
450 views

Clustering a bivariate data set with Mathematica

I need to partition a bivariate data set into predetermined "n" clusters and, at the same time, to fix the centroid position of each cluster. Is the ...
4
votes
2answers
374 views

How to fit one distribution to another?

I have a custom distribution created to model some experimental observations. While too complicated to include in this question, I can provide an example and some illustrations to convey a sense of ...
4
votes
2answers
283 views

How to make a conditioning plot?

I'd like to make a conditioning plot just like coplot in R. Is there a pre-made solution or do I have to make a bunch of plots individually? Edit: This is an example from r screenshots. It is a way ...
4
votes
2answers
374 views

Fitting data to an ARProcess using FindProcessParameters

I have 50 data points that I would like to represent as an AR(4) process. I'd like to over-plot the behaivor of the estimated process model with that of the original (raw) data before I use the model ...
4
votes
1answer
87 views

How to get an equivalent of WeightedData in Mathematica 8?

Is there an equivalent command of WeightedData (new in version 9) in Mathematica 8 or I have to define it by myself? I haven't found anything in the site or ...
4
votes
1answer
136 views

Defining five-parameter Pearson distribution by moments

How do you derive (or where can I find a derivation of) the equations to match the five parameters of a general Pearson distribution to a mean, variance, skewness, kurtosis, and condition that the ...
4
votes
1answer
315 views

Using DistributionFitTest on custom distributions in Mathematica 8

I originally posted this question on Stack Overflow, but I didn't get any answers, and I'm hoping to have better luck here. I'm trying to compute the goodness-of-fit of a bi-modal Gaussian ...
4
votes
1answer
108 views

NExpectation not up to expectations with Boole or Conditioned

Context I am interested in computing numerically the number of extrema at a given threshold for random fields. These numbers are expectations of MultinormalDistributions. Problem This integral ...
4
votes
1answer
243 views

How does Mathematica estimate error on fit parameters?

When performing a fit using NonlinearModelFit (or any of Mathematica fitting functions, but I am particularly interested in nonlinear models), Mathematica makes a ...
4
votes
1answer
206 views

AR(1) Process first term

I'm trying to generate a very simple AR(1) Process with Mathematica using the ARProcess[] function. The process must have the following format: $Y_t = \alpha + ...
4
votes
0answers
87 views

Sparse Principal Component Analysis

I'd like to run sparse PCA on some economic data. There appear to be several R functions available including elasticnet and PMA but I wanted to check if anyone had something coded up directly in MMA ...
3
votes
4answers
201 views

Descriptive statistics of two events

I am trying to use the descriptive statistics feature of Mathematica to answer the following question: suppose I have two events, A and B, whose occurrence is described by a normal distribution around ...
3
votes
3answers
260 views

Log-log scale smooth histogram

How can I create a smooth histogram with a log-log scale? I can use Histogram[data, "Log", "LogCount"] to get a log-log histogram, or I can use ...
3
votes
2answers
299 views

Conditional T distribution

Suppose $(X,Y)$ has a bivariate t distribution. I want to plot the density of the conditional density of $Y$ given $X$, i.e. $Y|X$. I wonder why the following does not work: ...
3
votes
2answers
550 views

Is there a function to calculate studentized range?

Is there a built-in function for studentized range or do I have to build it myself? Is there a test of normality for the studentized range?
3
votes
3answers
174 views

How to partition a list into sublists in a similar way to Histogram

I have a list of list as below (I show part of it) ...
3
votes
2answers
89 views

Expected sum of largest 3

I pick 4 numbers from the Uniform Distribution. I need the expected value of the sum of the 3 largest. I am pretty sure that the answer is 9 / 5 which agrees with a simulation. I would like to get ...
3
votes
1answer
215 views

Getting slightly different results in fitting a logit model in R and Mathematica

I'm fitting some data to a Logit model in both Mathematica and R and I'm getting slightly different results. R code: ...
3
votes
1answer
214 views

How do you pattern match a DataDistribution

I have a function, f[dist_, samp_]:=somework[dist, samp] that I want to return Null or zero if passed a null distribution. I ...
3
votes
1answer
97 views

Testing for OLS Heteroscedasticity White's General Test

I've done my best to search the help and google White's test (http://en.wikipedia.org/wiki/White_test) in Mathematica. Can anyone point me to a function or Mathematica reference for this or do you ...
3
votes
1answer
112 views

I need a technique for determining and drawing a line where the density in a listplot jumps up suddenly

Basically I have a two dimensional list plot with a bunch of points between the square of (0,0) and (1,1). The y-values of these points are drawn from a uniform probability distribution between 0 and ...