1
vote
1answer
31 views

Implementing bayesian networks in python for gaze estimation using visual saliency

I am developing an appearance based gaze estimation system based on opencv and python. I have currently developed a prototype which can estimate the gaze based on active calibration, which is ...
0
votes
0answers
8 views

How should I combine this binary scale with a 4-point scale?

I'm doing a meta-analysis and I want to combine the results of two questionnaires. One questionnaire has 30 questions about whether you've experienced certain traumatic life events. They're all ...
0
votes
0answers
11 views

VC Dimension of the set of canonical hyperplanes

This is a proof of the theorem about VC Dimension of the set of canonical hyperplanes from Professor Mohri's lecture slide. I'm having difficulty with understanding the inequality$$ \forall i \in ...
0
votes
0answers
5 views

mean and standard deviation of a population [on hold]

you are given a sample of a temperature in one month in the city over the past hundred and thirty years. three days it was 50 to 59 degrees 307 days it was 60 to 69 degrees 1439 days it was 70 to 79 ...
0
votes
0answers
10 views

Prerequisites for time series and ARIMA

I am working on forecasting sales for 2016. The details of the problem is: 2014 - sales happened only between Jan-Apr 2015 - Sales happened only between Jan-Apr The sales in rest 8 months of the ...
0
votes
0answers
20 views

Upcoming areas in theoretical Bayesian Machine Learning [on hold]

I will soon be going for a postdoc position at a new university. One thing that the panelist asked me to think of is if I were to start, what would I work on. Now the thing is so far with my PhD ...
0
votes
0answers
8 views

Missing block (Multilevel Modelling, repeated measures)

Experiment: participants respond to a moving object. Explanatory variables: velocity of object (fast, slow), Type of object (A,B). There are four different types of blocks, each with 16 trials: ...
0
votes
0answers
17 views

Advanced Method in Machine Learning to Learn Objects Position

I have done research about tracking of human body, face, hands, pedestrian etc. Can you point me to the methods in machine learning that learn the changes in position of multiple objects for object ...
0
votes
1answer
28 views

Calculating force of mortality from life table

The force of mortality at age $x+t$, given survival to $x+t$ is given by $\mu_{x+t}$ $=-\frac{d}{dt}[ln({}_{t}p_{x})]$ Given a life table I know how to calculate ${}_{t}p_{x}$, but then how can I ...
2
votes
0answers
20 views

Comparison of Bernstain and Chebyshev inequalities applied to Bernoulli distribution - simulation in R gives unexpected results

I'm trying to compare Bernstein and Chebyshev inequalities applied to Bernoulli distribution with parameter $p$. More specifically - how good are bounds they give for different sample sizes. I wrote ...
-1
votes
0answers
22 views

Weak classifier with Naive Bayes

I am trying to train weak classifiers from a specific data set, so I can boost them later on(with Adaboost). I have tried using Naïve Bayes as a weak learner. Here D1 is the expected output. Since ...
0
votes
1answer
10 views

How do I perform a Wald Test with multivariate Granger Causality Analysis

I am doing a Granger Causality Analysis for three economic variables (GDP, CO2 emissions and Total Energy Consumption) of Puerto Rico. I am using a Toda-Yamamoto Procedure implemented in R R. I am ...
0
votes
0answers
8 views

Error bars from a set of points at different x values [on hold]

Say I have a set of 4 data points all at different x values. They fall approximately on a line, with fairly small noise. How can I estimate the standard deviation, or some reasonable measurement of ...
0
votes
0answers
7 views

birnbaun saunders regression model [on hold]

i am running a birnbaun saunder (BS) regression model. My response variable is amount( in dollars) and my predictor variable is operational time ( in %). please which code will i use to generate it ...
0
votes
1answer
16 views

gam models with random effect R

I am modeling fishery CPUE as a function of a number of a number of covariates using a GAM approach that includes fixed and random effects. I understand that there are limitations with regards to ...
0
votes
1answer
29 views

Is it appropriate to use t-tests to find the most different outcomes?

I have a large CSV file of spending by individuals on different drugs. I want to find the drugs with the most different spending patterns by gender. The file looks a bit like this, but with 7.5k ...
0
votes
0answers
15 views

What does the sigma^2 figure mean when fitting a model to a time series in R?

I have a time series in R, and I am using the arima function to fit it to a SARIMA model. I would like to use the parameters it returns to write the time series equation by hand, but in order to do ...
0
votes
0answers
18 views

What is the best way to extract time-series shared by two variables?

I have one dependent and several independent variables. I want to extract the time-series of the independent variable that is shared with the dependent variable. In other words, I want to extract only ...
1
vote
1answer
21 views

Generating 2D different shapes with same mean and covariance matrix

Im trying to reproduce the synthetic data used in this article. The authors claim the data was generated from densities with the same mean and covariance matrix. Is there any principled way I to ...
3
votes
2answers
104 views

Adjustable sample size in clinical trial

Most clinical trials I see have a fixed sample size. In some cases they have prior data that allows estimating the effect size and the variance or distribution of values, and calculate the sample ...
1
vote
0answers
16 views

Find bins for observations where each bin has similar mean

I have 100000 observations with two variables on each, age on the range of 18-80 and interactions on the range of 1-1500. I want ...
4
votes
2answers
51 views

Analyze trend given a set of points

Suppose I have a set of N values representing EUR/USD rate... [ 1.10 , 1.20 , 1.25, 1.20, 1.19 ] Which is the simplest way for analyzing if values tend to raise or tend to fall? I'm looking for a ...
0
votes
0answers
5 views

RSNNS neural networks, checking percentage correct.

For those who have some experience with RSNNS, I'm trying to build a neural network for reading aloud, using RSNNS in R. To give some information about what I'm doing and using. I'm using orthographic ...
1
vote
1answer
17 views

Is there a difference between on-line learning, incremental learning and sequential learning?

What I mean is the following: Instead of processing all the training data at once and calculating a model or hypothesis, we process one data point at a time and update the model directly afterwards. ...
0
votes
0answers
6 views

Correlation computing time series data of unequal sample size

I am working on a computing a correlation between two variables X and Y. Both are time series and were recorded during the same period. 6/25/15. However X was recorded much more often than Y. ...
0
votes
0answers
10 views

Which time series model to use?

Hi I have a large data set of objects, each containing a list of the same attributes. The data is arranged in a time series so that the value for an attribute for an object is indexed by its time. ...
1
vote
0answers
21 views

linear regression with autoregressive errors ~ARMA(1,0)(2,1)[12]

I am fitting monthly data that are expected to be auto-regressive (streamflow), but I want to include other independent variables (in my case it is a multivariate regression, with about 4 variables). ...
0
votes
0answers
5 views

Connecting vertices in a graph stochastically. How to calculate a joint condition?

Full disclosure: I've posted this on reddit at /r/askstatistics, but haven't gotten any feedback yet, so I'm re-posting here in the hopes of getting some more exposure. Sorry for the long question. I ...
0
votes
0answers
14 views

Covariance of ARMA (2,1)

I am preparing for an exam and need help. Consider the following estimated ARMA(2,1) model, y(t) = 0,05 + 0,83y(t-1) + 0,13y(t-2)- 0,15e(t-1) + e(t): Given the unconditional variance and 1st order ...
1
vote
1answer
47 views

Combining principal component regression and stepwise regression

I want to use a combination of principal component analysis (PCA) and stepwise regression to develop a predictor model. I have 5 independent variables (which are correlated among each other to ...
1
vote
0answers
18 views

Overfitting of Regression with Robust Variances?

I performed regression with robust variances (after Stata 12.1 lnskew transformation). A question of overfitting has been raised. To summarise what I did: [1] Comparison of BrS (disgrp=2) vs ARVC ...
0
votes
0answers
8 views

Why are standard errors the same in lag-distributed model in R?

I am running a lag-distributed model ordinary least squares in which a set of units are all treated in the same year. I am including a 2 lags and 2 leads to see if there were any "anticipation" or ...
0
votes
0answers
13 views

Svm for survival analysis in r [on hold]

Is there any implemented package for survival analysis with SVM in R? I need to feed the model with both survival time and event. Thanks!
1
vote
1answer
15 views

Mediator reverses direction of causal variable. How to interpret?

I'm running a mediation in SPSS as per Baron and Kenny's guidelines (using regression). X is a dichotomous variable; M and Y are continuous. Step 1) X-->Y (r = .07, p = .03) Step 2) X-->M (r = .45, ...
0
votes
0answers
23 views

Validity of pre-established scale when dropping item as suggested by CFA

During my CFA I was forced to eliminate one item from the market orientation scale (well-established scale) due to poor loading which reduces the model fit. My PhD examiners asked me to explain the ...
2
votes
1answer
37 views

Get survival rates from a cox regression in R

I am fairly new to survival analysis and am playing around in R. I have a fairly simple cox model ...
6
votes
1answer
51 views

Significance of regression coefficients and their equality

Suppose, we want to regress $y$ on $x_1$ and $x_2$, i.e. $$ y = \alpha + \beta_1 x_1 + \beta_2 x_2 + \varepsilon \hspace{1cm} (1)$$ Is it, in principle, possible that simultaneously: $\beta_1$ is ...
1
vote
1answer
23 views

Time series analysis with known outliers

Let's say I have a time series of site usage data that I would like to analyze. The data is for people visiting my site, with a known seasonality that I can easily calculate, but in addition, there ...
1
vote
0answers
10 views

Efficient Triangular Backsubstitution in R [migrated]

I am interested in solving the linear system of equations Ax=b where A is a lower-triangular matrix (n $\times$ n) and b is a (n $\times$ 1) vector where n $\approx$ 600k. I coded up backsubstitution ...
0
votes
0answers
10 views

How to minimize setup cost in linear programming model using R [migrated]

Suppose we have a matrix m: > m C1 C2 M1 70 80 M2 50 61 M3 45 40 with machines M1-M3 and customers C1-C2. The values indicated the product volume that each ...
0
votes
0answers
16 views

Maximum lag selection for panel unit root tests

I am interested in conducting panel unit root tests on a panel of subregional annual data where N>100 and T<10 (more specifically, depending on the independent variables included in each ...
0
votes
2answers
23 views

Tests of heteroscedasticity in linear regression models

I am unfamiliar with the implementation used in the R package GVLMA. What are some basic tests of heteroscedasticity in linear regression models and how or where ...
0
votes
0answers
6 views

How should I measure difference between user behavior / model performance on different population?

I am developing a recommendation engine whose goal is to suggest data exploration routes to non-technical users. The underlying model is content based, with the training data made up of the behavior ...
1
vote
0answers
10 views

Likert scale dependent variables

I am doing a research about the ethics in pharmaceutical industry. I've chosen 7 branding activities followed by pharmaceutical companies. I want to study the relationship between the perception of ...
0
votes
0answers
12 views

Detecting linear connection between only several measurements in PCA (or any orther method)

$X$ is an $n\times p$ data matrix that has $n-d$ random measurements and $d$ highly correlated measurements, i.e. $X_{n-d+1+i}=b_i+a_iX_{n-d+1}+W_n$ for $i=1,2,...,d-1$, $a_i,b_i$ are unknown ...
0
votes
0answers
18 views

How is the entropy calculated by the `entropy` package in R?

So, as per the docs, I'm calling the function like this v = c(0,4,3,6,7,3,2,3,4,5) entropy(discretize(v, numBins = 8, r = c(0,7))) and I get ...
0
votes
0answers
11 views

How to make a 4X6 matrix from a 6X6 diagonal matrix in MATLAB [on hold]

I am having a diagonal matrix A = diag(a,b,c,d,e,f) which is a 6X6 matrix. From this I want to make 4X6 matrix specified by: B(1, :) = [a b 0 0 0 0] B(2, :) = [0 0 c 0 0 0] B(3, :) = [0 0 0 d e 0] ...
0
votes
2answers
19 views

Test Control. A longitudinal study

I have two samples of the same size, one being the 'treated' group, and the other used as a 'control' group. Each group have a different univariate variable (stress level), repeatedly observed over ...
0
votes
0answers
6 views

Longitudinal data with different response measurement types

I intend to fit a generalized linear (possibly mixed) model to longitudinal count data. However, I am running into an issue. The response I am modeling is a measure of student activity involvement. At ...
0
votes
0answers
6 views

Convert coordinates to neighbor list for spatial analysis in R using INLA [on hold]

I am trying to do an analysis of two greyscale images taken a few seconds apart, where each pixel in the first image should be predictive of the pixel in the second image. In general pixels near each ...

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