0
votes
2answers
27 views

No regularisation term for bias unit in neural network

According to this tutorial on deep learning, weight decay (regularization) is not usually applied to the bias terms b why? What is significance (intuition) behind it?
0
votes
0answers
8 views

Model fit VS R-square in path analysis

This is more a conceptual problem, as path analysis (without latent variable) is basically regressions, can I say the model fit indices is something similar to the F value? Usually in regression, ...
0
votes
0answers
14 views

Don't know how to properly weight this calculation [on hold]

Seeking expert help. I have customer analysis problem I'm trying to solve. I have 4 segments of customers, which are: Segment A Segment B Segment C Segment D ...
1
vote
2answers
25 views

Recurrent vs Recursive Neural Networks: Which applies better for NLP?

So, we have Recurrent Neural Networks and Recursive Neural Networks. Both are usually denoted by the same acronym: RNN. According to Wikipedia, Recurrent NN are in fact Recursive NN, but I don't ...
0
votes
0answers
14 views

Difference between autocovariance and autocorrelation [on hold]

I read from a book when i read about Yule-Walker estimation that "autocorrelation has nicer properties than autocovariance".. can any one tell me why please
1
vote
2answers
24 views

How to find conditional distributions from joint

I want to learn about how to do Gibbs sampling, starting with finding conditional distributions given a joint distribution. While looking for examples, I found this blog post that I wanted to ...
1
vote
0answers
15 views

LOOCV vs. AIC for Weighted Multiple Regression Model Selection

I am currently trying to determine the most predictive weighted multiple linear regression model to use. I don't have much formal statistical training, so I would greatly appreciate any help with the ...
0
votes
1answer
16 views

For a one-tailed test using OLS regression in SPSS, is it appropriate to divide the change statistics p-values in half?

I am running a series of moderation regression models in SPSS and entering the models in using blocking (e.g., controls in block 1, controls and IVs in block 2, controls, IVs and moderator in block ...
0
votes
1answer
26 views

Is structural equation modeling (SEM) just another name of confirmatory factor analysis (CFA)?

I am reading some material about structural equation modeling. I found it to be extremely similar to confirmatory factor analysis - modeling a construct as the linear combination of several other ...
0
votes
0answers
19 views

Random slope and random intercept correlation at every level of X

Lets say individuals are nested within each ID and I am trying to a predict level 1 outcome Y from a level 1 predictor X1 or X2 with random slopes and intercepts. X1 and X2 are equivalent to each ...
0
votes
0answers
14 views

Estimating treatment effects on unequal groups

The setup is quasi-experimental: treatment and control groups, chosen ahead of time, are given a pre-test and a post-test. They are close to equal in size, and while membership was selected based on ...
0
votes
0answers
6 views

ANCOVA model with non-significant variables performs better?

I'm running an ANCOVA test with 2 dichotomus and 1 ordinal variable as fixed factors and 2 continuous variables as covariates. I was advised to remove any non significant factors because with them ...
1
vote
0answers
14 views

Need an effective way to show distribution changes over time and outlier reoccurence

Does anyone have suggestions on the best way to approach this problem? I have a large dataset (over 200k+ per day) in a MySQL database, that consists of a single record per user per day with a ...
0
votes
0answers
12 views

Class imbalance problem - Random under sampling

I have a class imbalance problem in my data set (99.5%,0.5%). I understand that there are various sophisticated ways to deal with this problem, but I am trying a fairly simple approach - Random under ...
3
votes
1answer
22 views

References for tiny sample statistics

There are multiple fascinating problems and approaches connected to really small samples. It is possible to estimate confidence intervals using a single point, or there are well known problems such as ...
1
vote
0answers
35 views

Recovering number of planets in a sample

I have a sample of $N$ stars (where $N \approx 5000$). Each star might host 0, 1 or more planets; each planet around star i has a probability $p_i$ of being detected (independent of whether or not any ...
0
votes
1answer
15 views

How to implement knn in r with missing values?

I have this data set from https://archive.ics.uci.edu/ml/machine-learning-databases/credit-screening/crx.names which gives a good summary of the attributes im using. Some of the observations are ...
0
votes
0answers
7 views

Implementing the Bayesian Information Criterion (BIC) Using PyKalman

I'm trying to use pykalman to do a Kalman filter on financial data and it seems to be generally working very well. However, when I attempt to extend the code using BIC $\mathrm{BIC} = {-2 \cdot ...
1
vote
1answer
10 views

Combining text and non-text features

I am working on a binary classification problem using SVM. I am currently using ksvm in R (kernlab package). The input is a combination of text and scores. I would like to be able to use substring ...
0
votes
0answers
12 views

classification, discrimination, prediction, clustering

note: i am restricted to using SAS in this project, no R).The purpose of my problem is to predict the response variable. to start off, I have a large dataset (medical study on diabetes prevention) ...
0
votes
0answers
12 views

How do we know that a certain copula family will be suitable for our data?

I have longitudinal data with repeated measurement over 5 time points. I constructed its multivariate distribution using Gaussian copula. Is there any way to choose the best copula (analytically, ...
0
votes
1answer
28 views

Neural Networks and Numeric Prediction

I'm new to machine learning and am trying to write a simple neural network that uses back-propagation. Now, so far I've successfully implemented my neural network to learn a boolean function. So for ...
2
votes
0answers
30 views

Estimating probability distribution function of data stream

Although a similar question exists, I couldn't find my answer. I'm not a statistician hence please neglect if some terminologies aren't correct and let me know if I am interpreting something wrong. ...
0
votes
0answers
10 views

High asymmetric binary variables [on hold]

I have a set of binary dependent variables where most values are concentrated in one category. Which methods are adequate to analyze such data and which restrictions or difficulties are usual in this ...
1
vote
0answers
25 views

Is correlation required condition for causation? [duplicate]

We all know that Correlation does not imply causation, but I am wondering whether there can be causation without correlation. If there are such cases, could you explain them? I am asking this ...
2
votes
0answers
26 views

How to optimize and compare search algorithms with only a statistical measure of success?

Using the U.S.A. as a loose analogy, our goal is to find the the maximum number of States adjacent to a given State (containing a selected city) with the minimum number of "probes" or "hits". ...
5
votes
0answers
79 views

What's wrong with this visualization of eigenvalues/vectors/PCA?

I have a dataset of 17 people, ranking 77 statements. I want to extract principal components on a rotated correlation matrix of correlations between people (as variables) across statements (as ...
1
vote
0answers
18 views

Make 2D color histogram with uniform distribution (Likert scale)

UPDATE: I've been told that I cannot specifically ask for help in regards to the programming (MatLab and PR Tools), but instead should seek help for general techniques. So that's what I'm doing. Long ...
1
vote
0answers
20 views

Survey methods to be used with a pearson correlation

I'm doing a small project for school analysing the relationship between the results of a survey and how they compare to some performance data for an organisation. After deciding to use Pearson ...
2
votes
0answers
23 views

Finding the optimal combination of independent variables for a constrained dependent variable

I'm currently working on power plant time series data and my main objective is finding out the optimal combination of independent variables which would keep "SO2 concentration (dependent variable) ...
0
votes
0answers
18 views

Find sample size of all interactions for cross classification GLM in R [on hold]

Suppose that I have a response variable called A and four explanatory variables that are all factors (all with at least 3 levels) called B, C, D, and E. I know that the total sample size of my data is ...
4
votes
2answers
54 views

Sequential pattern mining on single sequence

Can someone give me a hint about a good approach to find a frequent patterns in a single sequence. For example there is the single sequence ...
0
votes
0answers
10 views

Interpretation of non-significant parameters in significant Cox-model as prognostic factors

I want to analyze predictive factors for patient survival after surgery. I have variables that are based on investigations at the time of the surgery, known predictive factors (age, KPS) and data on ...
0
votes
0answers
18 views

CONFIDENCE INTERVALS FOR THE MEAN OF A NORMAL DISTRIBUTION [on hold]

I have the following sample that I don't understand How to find that z0.99=2,33 ?
0
votes
0answers
12 views

Confidence interval for the difference of two proportions from small sample size

Suppose I have two trials with small sample sizes such that the event rate for the first trial is $p_1=2/25=0.08$ and for the second trial $p_2=3/20=0.15$. I am wondering what may be the best way to ...
2
votes
1answer
59 views

Comparing models in linear mixed effects regression in R

I have a very large data set with repeated measurements of same blood value (co) (1 to 7 measurements per patient). Each measurement is coupled with time which is the time interval between surgical ...
0
votes
1answer
24 views

How can I find out the needed sample size

I'm going to study if medical reconciliation diminishes the amount of inappropriate medications amongst elderly people in a small part of Sweden. I will count the number of inappropriate medications ...
1
vote
0answers
17 views

Can I use a partial eta squared on t-test results?

I am currently trying to decide which effect size is the most appropriate for my results. I have conducted a repeated measures ANOVA, there are five variables in the ANOVA, all of which are within ...
0
votes
1answer
16 views

Seasonal component in irregular time series

Is it possible to identify seasonality in a Time Series that is irregular? I am currently working with a time series that is being periodically constructed (via crawling), but these crawled ...
0
votes
1answer
18 views

Intuition behind sparsity in over-complete sparse auto-encoders

I am trying to get a grasp of the intuition behind the sparse representation used in over-complete auto-encoders. One piece of text that offers a somewhat intuitive explanation is from ...
0
votes
0answers
36 views

Non-linear regressions with caret package in R [on hold]

i'm new using R and my doubt is really basic. I have several dependent variables (x) and one independent variable (y), and I'd like to generate different regression models with ...
3
votes
0answers
69 views

Comparison between regression of $a = bc^t$ and $\log a = \log b +t \log c$

This question is more qualitative then about the maths behind the equation. Variables: a = month (1, 2, 3, ) t = shipments of a product in that month You wish to derive the relationship between $a$ ...
0
votes
0answers
16 views

Normalization before feature selection such as Fisher score (F-score)

The Fisher score (F-score) for feature selection is defined as in Combining SVMs with Various Feature Selection Strategies. However the paper doesn't mention any preprocessing to feature values such ...
0
votes
1answer
23 views

What is batch size in neural network?

I'm using Python Keras package for neural network. This is the link. Is batch_size equals to number of test samples? From ...
0
votes
0answers
5 views

How many data points are needed for RBM training?

If $n$ is the number of visible units, and $m$ is the number of hidden units, how many data points are required for RBM training? The goal of the learning process is finding interesting correlations ...
1
vote
0answers
16 views

calling R2OpenBUGS with Wine on Mac [on hold]

I really don't know where to go for a solution to this problem. This may not be the right place... I also tried stackoverflow but got no response. Any suggestions gratefully received. I'm trying to ...
1
vote
0answers
24 views

How to determine if a categorical variable affects an independent variable?

I am looking at the wine dataset from the R FactoMineRpackage to find out whether the categorical variable soil type affects the ...
21
votes
3answers
1k views

Why are there two spellings of “heteroskedastic” or “heteroscedastic”?

I frequently see both the spellings "heteroskedastic" and "heteroscedastic", and similarly for "homoscedastic" and "homoskedastic". There seems to be no difference in meaning between the "c" and the ...
2
votes
1answer
58 views

How to test if a percentage is significantly higher than 0?

I have asked people to rate different items between 0 and 100. On one condition, most of the items were rated very low. Therefore, the distribution of the result looks like an negative exponential. ...
-1
votes
0answers
21 views

Finding two independent means in a collection of data

I have a process that supposedly can run in two different modes with executions times of T1 and T2 respectively. Also the process runs in one mode more often than the other. The process is a computer ...

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