1
vote
1answer
20 views

In a random forest algorithm, how can one intrepret the importance of each feature?

I am in the process of building a Random Forest algorithm in MATLAB using the TreeBagger function. In the documentation, it returns 3 parameters about the importance of the input features. My ...
-1
votes
0answers
11 views

Set all values of a column to zero conditionally by factor level [on hold]

I am trying this in R I have the following variables in a data frame: X1 (numeric) X2 (numeric) ... X100 (numeric) X101 (factor with 5 levels) X1 to X100 are numeric I want to do the following: For ...
1
vote
0answers
17 views

Model for count data with different exposure time (some times are terminated by death)

I am looking for most suitable model for count data in the following case: we collect number of patient's visits in a hospital for $t_i$ days ($t_i$ varies across subjects) some patients died ...
1
vote
0answers
9 views

Can I Use DFT To Find The Most Common Frequency?

I have a collection of data which measures the change in state of a device which records information. I basically record the time a new observation is made on the device. I want to collect the data ...
0
votes
0answers
4 views

Testing Proportional Odds Assumptions

I am working in R with a response variable that is the letter grade the student received in a specific course. The response is ordinal, and, in my opinion, seems logically proportional. My ...
5
votes
0answers
27 views

how does the beta function make the total probability of Dirichlet distribution integrate to 1? [duplicate]

the Dirichlet distribution $$Dir(\boldsymbol\mu|\boldsymbol\alpha)=\frac{1}{B(\boldsymbol\alpha)}\prod_K\mu_k^{\alpha_k-1}$$ How is the normalization term $B(\boldsymbol\alpha)$ calculated? or in ...
0
votes
0answers
5 views

clustering segmentation

I am trying to create customer segment using set of customer features. I have dependant variable like revenue of a customer by different product categories. I am trying to create segment that are ...
0
votes
0answers
11 views

Question about the Probability of Error for Joint-Typicality Tests

Given a set of codewords $\boldsymbol{x}_i$ with $i=1,\cdots,2^{nR}$ where $R$ is the rate of the code. The codewords are transmitted over a Gaussian channel $Y = X + W$ with $X\sim\mathcal{N}(0,A^2)$ ...
0
votes
1answer
9 views

How to combine a set of features and report their effectiveness with only one number?

I have a binary classification problem. My data set has 100 features with 10 different categories (10 features per category). I want to report the effectiveness (in terms of classification) with a ...
1
vote
0answers
24 views

Data structure for rare event predictions in temporal domains

I am a beginner in rare event modeling. I am working on predicting modem failures within a network where failures occur approximately 3% of the time. Currently my data is structured as follows: ...
-3
votes
0answers
5 views

invoke pipeline functions in sklearn [on hold]

i want to invoke sklearn pipeline with a function to transform the sparse matrix output from feature extraction process to the guassianNB() classifier ...
2
votes
0answers
11 views

ML and Flow Maximization

I've been wondering if you guys ever saw ML being used to assist a Max Flow algorithm? I have a very large directed graph that has some fractal characteristics, meaning that this large graph can be ...
-1
votes
0answers
5 views

Adaptive Linear Neurons (ADALINES) Algorithm Not Printing Graphs [on hold]

I am working on an ADALINE algorithm in python, and I am printing the graphs in the code, but when I run the program the graphs do not print. Any help with that or suggestions to improve the algorithm ...
0
votes
0answers
53 views

Poisson regression? [on hold]

If we have a $y_i$ random sample with a $Poisson(\lambda_i)$, $i=1,2,...,n$. Also $\log(\lambda_i)=(X\beta)_i$ where $X$ a known $n \times p$ matrix and $\beta\in\mathbb{R}^p$ is not known. Assuming ...
0
votes
0answers
13 views

What are scientific questions one may ask regarding a univariate time series?

What are scientific questions that one may ask regarding a univariate time series besides forecasting/prediction?
0
votes
0answers
12 views

Poisson regression residual analysis

In a three factor poisson (log-linear) model $(A*B*C)$, when the highest interaction term $(A:B:C)$ is dropped, the response/raw residuals are exactly the same for different levels of two of the ...
0
votes
0answers
10 views

Unbiased proportion estimate for a 2-component Gaussian mixture model?

Suppose I have a 2-component Gaussian mixture model of dimension $p$, where each mixture has the same covariance matrix: $$ \pi_1 \mathcal{N}(\mu_1, \Sigma) + \pi_0 \mathcal{N}(\mu_0, \Sigma) $$ ...
3
votes
2answers
42 views

Pattern detection in scatter plot

Below is a scatter plot (capped at $10k) representing the average donation a project receives vs the word count of the funding request essay for all projects represented in the open Donors Choose ...
0
votes
0answers
11 views

Finding Correct Distribution For Data

I'm working on a project, and I am trying to figure out the probability of where in a certain time frame an event will land. I am trying to find a distribution that resembles my data, but the problem ...
0
votes
0answers
13 views

Identifying outliers in time series with decomposite in R

I have time series data, from a period in which it is reasonable to assume the seasonality is the. I used decomposite in R to get a multiplicative decomposition. I know, ex-ante, periods where I think ...
3
votes
0answers
25 views

Asymptotic conditional expectation

Problem Setup Let $\{X^d_1, X^d_2, \cdots, X^d_n\}$ be a $d-$dimensional zero-mean, i.i.d. random variables. Let $S_n^d$ be $$ S^d_n = \frac{\sum_{i=1}^n X_i^d}{\sqrt{n}} $$ Let $Y^d$ be a ...
0
votes
1answer
44 views

Exercise in Bayesian Statistics

What I want to do is the first part of the exercise : It is for chapter 14 of the book, an introduction to regression. I have minimal experience with regression and is the first time I see a ...
2
votes
2answers
49 views

Conditional Expectation of a function and another Conditional Expectation

Suppose $\{X_1,X_2,Z\}$ is a vector of 3 real valued continuous random variables with compact support, $f_1(X_1,X_2)$, $f_2(X_1,X_2)$, and $g(X_1,X_2)$ are measurable functions with at least 2 ...
0
votes
1answer
9 views

Sample size - prioritizing issues

Hi I am about to distribute a survey that asks stakeholders to pick from a list of 20 issues, the top 3 they feel are important. I am not doing any hypothesis testing but ranking the results based on ...
0
votes
0answers
7 views

Simultaneous Equation Model with Fixed Effects [on hold]

Can someone please clarify the appropriate method for running a 3 equation simultaneous equation model with fixed effects estimation? In my model, each of the dependent variables depend on the other ...
0
votes
0answers
21 views

PYMC error:pymc.Node.ZeroProbability: Stochastic A's value is outside its support, or it forbids its parents' current values

I asked this question in stackoverflow but closed it after 4 days since I didn't get any answer. I am using this example as a basis for my work: I am trying to use pymc MCMC to fit the parameters of a ...
1
vote
0answers
19 views

Using several cross-sectional regressions (for different years) vs. a single fixed-effects panel model

I have what I think is a relatively simple question about the merits of performing a single panel regression with fixed effects as opposed to individual yearly cross-sectional regressions with the ...
2
votes
1answer
23 views

LSTM time series with mixed frequency data

I want to make a LSTM RNN for timeseries prediction, but some of my predictors are monthly and others are daily. Any advice / examples on how to set up this network? The frequency of the ...
2
votes
1answer
17 views

Optimal Combination Forecasts

Can someone give me an intuitive explanation of how Optimal Combination Forecasts work for hierarchical time series? I've been reading Rob Hyndman's paper and understand that the resolved forecasts ...
0
votes
0answers
5 views

Comparing homogeneity of variance and t-test

I have categorical variable with 2 levels having more than 1 response variables for Shapiro-Wilk test? I tried shapiro.test(abdata$Conductivity), how do I prepare ...
2
votes
1answer
23 views

How to determine xdy dice roll from a sample?

I'm playing an RPG based on DnD xdy dice damage rolls, where x is the number of dice rolled and y is the number of sides on each die. So, normal double-sixes dice people are familiar with would be ...
0
votes
0answers
12 views

Plot Volume Under Surface in R for multinomial logistic model [on hold]

I have a model with a response variable with 3 categories and I want to run a multinomial logistic model. Is there a mode to plot a generalization of ROC in the simple logistic model, like the VUS ...
0
votes
0answers
14 views

Use of weights in PROC GLIMMIX

I am looking to implement a generalised linear mixed model in SAS using PROC GLIMMIX. The data is from a survey, and a single ...
0
votes
0answers
15 views

Is there a way to force seasonality from auto.arima [migrated]

With the forecast package, I have a time series that I would like ?auto.arima to automatically pick the orders but I would like ...
0
votes
0answers
17 views

Heterogeneity testing in logistic regression models

We ran 5 separate logistic regression models testing a set of independent variables on 5 different country-specific datasets. Our goal was to assess the relative contributions of known risk factors of ...
3
votes
0answers
19 views

How to calculate odds ratio per unit decrease of continuous variable

I have a logistic regression model obtained in R comparing association between two index diagnoses (0 or 1) with Age (continuous) + ...
0
votes
0answers
20 views

How to test the inclusion of a single random effect in glmer?

Suppose I have two models: m1=glm(DV~IVs) m2=glmer(DV~IVs+(1|Subject)) How can I test the inclusion of that random intercept in R? I know that I can't use ...
0
votes
0answers
13 views

Is this following assumption of autocorrelation test right?

Basically I ran an autocorrelation test using first the d-watson test which resulted in an inconclusive result as it equaled du stat. Then I ran the durbin-watson alternative test which resulted in ...
0
votes
0answers
36 views

To call an api every minute from a URL, is R practically doable? Or would I need to do it in Python? [on hold]

I'm wondering if R is practical enough to call an api from a URL every minute and update the set of data. Would it be better use of my time to do learn and do it on Python instead of R? Thanks
0
votes
0answers
10 views

Metric vs feature

I'm dealing with a supervised N-way classification problem. Input is a feature matrix (NxM), and label vector (Nx1). Would there by any difference between the following in terms of accuracy: 1) Use ...
0
votes
0answers
13 views

Test for equal variance for 2-way ANOVA

Forgive a novice in statistics for asking a perhaps very simple question, but I am running a two-way ANOVA with unbalanced design and want to test for homoscedasticity using Levene. For a one-way ...
0
votes
1answer
20 views

Linear AIgebraic interpretation of Standard Errors in ANOVA using R function

Background (can safely skip): I'm working towards some sort of computer illustration through a Monte Carlo, plotting, or linear algebra explanation, I don't know, of the effect of sample size on the ...
0
votes
0answers
15 views

How to perform a nested or hierarchical ordinal logistic regression in SPSS

I have one outcome/dependent variable that can be ordinal or nominal and 3 independent variables. I have learned so far how to perform ordinal and multinomial logistic regression in SPSS between a ...
3
votes
0answers
30 views

How to calculate probability of a random sampling of a population

Let's say that I have a city for which I know the size in square miles and I want to know the probability of a random sample of individuals from that population living within a certain threshold of ...
2
votes
0answers
11 views

Mahalanobis distance for highly multivariate random variable

I have to compute the Mahalanobis distance for a $10^6$ dimensional multivariate random variable. What is the best (and fastest) way to do this? I am currently taking cholesky decomposition of the ...
0
votes
1answer
11 views

Mixed-effect models for repeated measures - problems with the “Significance level”

I am trying to fit a linear mixed-effect model to my dataset to see the relationship between a self-reported questionnaire and some physiological data. I've created a first model including all the ...
0
votes
1answer
18 views

ARMA errors and combining explanatory variables

Currently I'm working on forecasting the employee turnover of an organisation. To do this, I'm using a time series data of the employee turnover over the past 7 years, it is an annual data. To make a ...
0
votes
0answers
8 views

how to choose the test dataset and train dataset in link prediction [on hold]

hi i need to know how to split my dataset as test dataset and train dataset for doing the experiment of prediction links (i will apply common neighbors jaccard coeifficent ...) the dataset i have is ...
0
votes
0answers
15 views

Random Forest: Strange Feature Importance Results for Constant Variables

I've been using the RandomForestClassifier in python's Sklearn package to assess the importance of the features in a large dataset with features that are both binary and continuous. I've done quite a ...
2
votes
0answers
16 views

Interpreting the Dickey Fuller test

I can't seem to make sense of the following results. The time-series looks more non-stationary than stationary, and when I fit an ARMA(1, 0, 0) it estimates the AR(1) term to be very close to unity ...

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