0
votes
0answers
3 views

Between Subjects ANOVA for Pre-Existing Groups

Based on the article here: http://ww2.coastal.edu/kingw/statistics/R-tutorials/oneway.html, there are 4 ANOVA assumptions that must be met: Random sampling, or at the very least, random assignment ...
0
votes
0answers
2 views

predictive models for panel data

I came across some practical problems with the data in similar form: item*features*time. Traditionally, data for predictive models in textbook is only ...
0
votes
0answers
7 views

Ambiguity of chi-squared test of association

Recently I have been struggling with the following two questions regarding the chi-squared test of independence / association during reading an article. Is the chi-squared test able to detect ...
0
votes
0answers
4 views

Creating a mixed model for repeated measure using lme function

I have a question about a selection of the most proper model and subsequent ANOVA for my experimental data. I have one response variable - Net assimilation (Anet). Then I have 5 categorical variables ...
0
votes
0answers
5 views

Creating a personnalized PCA (not using variance as optimization criteria)

I have a simple question (I hope I can explain it clear enough). I want to train and apply a PCA to a set of data (I want to have an orthogonal basis in a low dimension subspace with unitary ...
0
votes
0answers
6 views

media classification open-source software

I'm working on a multimedia/cinema project involving the classification of different kinds of media (primarily video but also audio and text) into a single database which needs to be queried. I intend ...
0
votes
0answers
13 views

Suggestions on statistical models

I have 6 independent categorical variables (x) and one dependent variable (time) y. What are some appropriate statistical modeling techniques if my objective is to predict time (continuous variables) ...
0
votes
0answers
5 views

Repeated measure, t-test on the sums?

I need some help to find a suitable hypothesis testing solution... To make my problem clear, I give you and example. Imagine my hypothesis is that firms in City A are more profitable than firms in ...
1
vote
0answers
9 views

Logistic Regression vs ANOVA for categorical variables

In a problem that I have to predict a categorical variable (0/1) using a set of categorical variables, does it make any difference in prediction accuracy whether I use a logistic regression or ANOVA? ...
0
votes
0answers
7 views

How to conduct a three way ANOVA with non-normal and heteroscedastic data?

I am currently trying to analyze a data set to check the effect of three factors (year, plant, water stress) on yield. But the distribution of my data is not normal. I tried several transformations ...
1
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0answers
5 views

Quantile Regression: follow up methods to have a more fine-grained understanding of what the results really mean?

I recently employed multiple quantile regression in my area of research and found some interesting quantile differences across the distribution of Y, but I don't quite understand what they all really ...
1
vote
0answers
4 views

Decision Trees rpart R categorical and continuous variables

I run some decision trees in rpart with 10 continuous variables and 3 categorical variables (with 1 or 0 options), the result of the tree was that none of the 3 ...
1
vote
0answers
5 views

Quantile regression with continuous endogenous variables

First of all, let me apologise if this question has been resolved elsewhere on the site / the net. I have been researching a methodology for IV Quantile regression with continuous endogenous ...
-1
votes
0answers
6 views

When to stop agglomerative hierarchical clustering - stopping criteria [on hold]

I am coding my application each function so i am not using tools which does everything for you Been looking for solution when to cut my agglomerative hierarchical clustering How do i cluster? I ...
0
votes
0answers
4 views

Comparing the within-subject variance between two groups of subjects

If each subject has repeated a test multiple times, I am able to compute the mean and variance of their performance. (I am assuming the results to be normally distributed). 1) If it is the variance ...
0
votes
0answers
6 views

Random coefficients in regression

Can I use the random coefficients extracted from a random coefficient growth model as predictors in a regression analysis? If the random coefficient growth model also contains a second-order ...
0
votes
0answers
6 views

Quantifying the error from a Bayesian model

I have a Bayesian model that predicts the chance of some event occurring. To view the accuracy, I took the prediction output of my test data and binned it every 10%. For example, if the model ...
0
votes
0answers
8 views

Coefficient in differences-in-differences regression significant for log-level specification but not for level level

I am estimating a differences in differences model: $Y_{it} = \alpha_i + \beta_t + \tau T_iP_t + \epsilon_{it}$ where $\alpha_i$ and $\beta_t$ are fixed effects, $T_i$ is a dummy variable indicating ...
0
votes
0answers
21 views

Interpreting steep histogram, fitting distribution

I'm trying to fit the distribution to the data. I started with histogram. Note that y axis is in logarithmic scale since the histogram is very steep. How should proceed to find actual ...
1
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0answers
7 views

Hypothesis testing for inaccurate sampling

My problem is as follows: Imagine a set of points, their positions have been recorded with a rubbish GPS, so are not precise and have a high error (assume no systematic error). Call this set $I$ ...
0
votes
0answers
9 views

Confidence band for mean of means

This is sort of a stats theory question, and I can't really convince myself of the correct way to view things: In normal regression, the confidence band (or interval) gives the bounds on the mean, ...
0
votes
2answers
8 views

Variable Selection Method for Multinominal Model

When dependent variable is categorical (more than 2 categories) and independent variable is continuous, is there any way i can check the predictive power of independent variable? Can i apply one-way ...
0
votes
0answers
6 views

Relation between Image and Kernel of matrix of sufficient statistics

Suppose we have a parametric statistical model formed by $p_x = \frac{L(\zeta, x)}{\sum_{y\in \mathcal{X}}L(\zeta,x)}$ where $\mathcal{X}$ is the sample space, $L(\zeta,x) = \zeta^{T(x)} = ...
1
vote
0answers
9 views

How capable are neural nets? Do I need to do feature selection?

I'm super new to Neural Nets and machine learning in general, so bear with me. I guess my question is "How capable are neural nets?" I've worked with the example of training a net to predict if an 8x8 ...
0
votes
0answers
6 views

Comparing two groups, each containing categories

I have two groups of patients, separated by surgical procedure. Each group has an associated set of features (emergent from the patients in the group), and the two groups may be a different size. What ...
0
votes
0answers
31 views

Maximum Likelihood Bernoulli Estimation - Discard Trials?

The problem can be shortly formulated as follows: suppose that we are studying the probability of a machine breakdown in an interval of one hour. In our sample there are N independent machines. Of ...
0
votes
0answers
9 views

Power and sample size [on hold]

I would like to test the agreement between two similar imaging tests. How do I determine sample size to power the study? I'm looking for a 10% difference and p<0.05
0
votes
0answers
6 views

Can you use cohens kappa to quantify classifier performance under a k-fold cross-validation

Sincere apologies if this is a dumb question, this is really not my area of expertise. I am training a quadratic discriminant analysis classifier (fitcdiscr function in matlab) and it is performing ...
0
votes
0answers
7 views

BIC in two step clustering

I am just running two step clustering; and I couldn't find the value of BIC after the performing the two step clustering. There /NUMCLUSTERS AUTO 15 BIC in the syntax. So where can I get the value of ...
0
votes
0answers
5 views

Drawing tangible insights from rpart model splits

I'm working on a data set for an engineering problem which involves the use of pumps. My main objective is figuring out how to reduce the number of pumps used where the maximum number of pumps is 4 ...
1
vote
1answer
22 views

Expected number of trials - Bayesian

ref: 2.11 Question 2. Gelman et al.: Bayesian Data Analysis 2nd ed Consider two coins, $C_{1} \text{ and } C_{2}$ with the following characteristics: $Pr(heads|C_{1}) = 0.6$ and $Pr(heads|C_{2})$ = ...
0
votes
1answer
44 views

About simple linear regression

If we assume a vector $y$ which has normal distribution with mean m and covariance matrix M. A simple linear regression model ...
2
votes
0answers
25 views

When is non-normality severe enough to warrant using different tests?

I've been doing quite a bit of reading on the topic of non-normality, and how it pertains to the F-test. My understanding is that non-normality tests aren't very useful, as outlined in the arguments ...
0
votes
1answer
34 views

Fitting known equation to data

I have measured growth rates over a range of temperatures (temperature response curve) and would like to fit an already established equation/model to it. I'm very new to R and have trouble coding it ...
1
vote
0answers
22 views

How to decide which interaction terms to include in a multiple regression model?

I am trying to build a multiple regression model using R. I have a number of predictor variables. I have some basic domain knowledge for which I am trying to build the model. To start with, I included ...
0
votes
0answers
10 views

R packages to calculate Effect Size

There are several R packages with functionality to calculate effect size. Recently I start to use the package pwr. Taking ...
0
votes
2answers
45 views

When the results do not support the research

Suppose that you have a research study about risks factors for kidney disease in a specific area (in the area live few people). In recent years there was a high prevalence of this disease ...
-1
votes
0answers
14 views

New to R , would like some help regarding statistical Arbitrage using R

I am new to R and I was wondering what R can do ? and if I can use it for actual trading using a statistical arbitrage . Basically I want to know if R can : 1. Find the correlation of stocks 2. Find a ...
0
votes
0answers
4 views

How can I have a predictive Termination & Active model? [on hold]

I am a newbie in R. I have a dataset. Year & Month Active is store in the network Enterprise. Termination is store that left the network Enterprise. With these two variables, I can calculate the ...
0
votes
0answers
17 views

Convergence in Probability to a Constant [on hold]

Let $X_{1}...X_{n}$ be a sequence of random variables that converges in probability to a constant a. Assume that $\mathbb{P}(X_i > 0 ) = 1$ for all $i$. Verify that $Y_{i}=\sqrt X_i$ and $Y_{i}^{'} ...
0
votes
0answers
18 views

Combinatorial optimization

Suppose I have some tasks $y_1$$, ... ,$ $y_k$ and some workers $1, ... ,m$ to do them. Furthermore, every task-worker combination has some cost $c_{ij}$ with $i=1, ...,k, j=1, ...,m$. In addition, ...
0
votes
1answer
7 views

Default value on missing columns of data frame in R [on hold]

In R, I've used rpart on training data and then tried to do a prediction on test data. Trouble is that some columns in the training data are missing in the test data; their values should be 0. Is ...
0
votes
0answers
7 views

Sparse Contingency Table Analysis

I am relatively new to categorical data analysis and was looking for some opinions on my analysis approach. I have 4 categorical variables, OUTCOME, X, Y, and Z. All are binary except for Z which has ...
0
votes
0answers
9 views

Hierarchical Multi-label Classification

I have a dataset which its lables are as following; "No", "SmallRiskofDisease", "LargeRiskofDisease", "Sick", I would like to make a disease prediction model, where the information between "No" and ...
1
vote
1answer
10 views

What analysis should we use for repeated measures when some only have the first or second measure?

We're doing a report on a teacher rating system. It finished its second year and in the report we have the percentages of teachers that received each rating (ordinal variable with 4 levels) for each ...
0
votes
0answers
9 views

How do I distribute answers lacking geo information from a poll?

My data table looks like this: Region Answer1 Answer2 NaN 20 40 Region1 15 17 Region2 18 19 ... So is it possible to distribute answers for which region is not ...
0
votes
0answers
5 views

Is kappa only useful for compensating against class imbalance?

Let's say you have a true/false random-forest classifier with a 50:50 split in the training data and 50:50 split in the test data; are the confusion matrix and accuracy a good enough measure of ...
0
votes
0answers
6 views

Standards for reporting propensity score matching

When publishing articles, there are international recommendations for reporting modeling such as the TRIPOD Statement (Transparent reporting of a multivariable prediction model for individual ...
0
votes
0answers
8 views

How much weight should be given to sample mean as an estimate of the population mean?

This R code creates a population of size 10,000 with a population mean of 3 and a population standard deviation of 2: population <- rnorm(10000, 3, 2) We can ...
0
votes
0answers
4 views

Extract details info from regsubsets [migrated]

Given a dataset, if we use regsubsets function in R, we are only able to plot the result using a scale like Adjusted R Squared: ...

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