All Questions

I know that if ALL the coefficients on the lagged values of, say, $y_2$ are $0$ in the equation for $y_1$, then $y_2$ fails to Granger cause $y_1$. Therefore, our null hypothesis for Granger ...

I performed a one-sided Wilcoxon signed-rank (WSR) test. I had a matched pair of continuous random variables, say $X_1, X_2, ..., X_n$ and $Y_1, Y_2, ..., Y_n$. For my system, it is safe to assume ...

I'm running a FCN in Keras that uses the binary cross-entropy as the loss function. However, im not sure how the losses are accumulated. I know that the loss gets applied at the pixel level, but then ...

I have these four data facts. please help me to understand the underlying data retention problem and solution. Qualitative survey results

Suppose I have the following model $y_i=\alpha+\beta_1*Revenue_i+\beta_2*IFRS15+\beta_3*Revenue*IFRS15+\beta_4...$ where Y = stock return, Revenue = actual revenue and IFRS 15 is dummy equal to 1 if ...

I'm trying to determine how to answer question from text with supervised learning. This used to work quite well when every questions had answers. Here is the head of dataset we used with the sentence ...

I am looking for an algorithm which can detect cyclic pattern in streams of characters which have random noise embedded in them. An example of cyclic pattern with a set of characters a - m for a ...

I am a beginner in machine learning, and I hope someone can help me. In Python's 'scikit-learn' library, the function 'train_test_split' splits the dataset into training and test sets. This is done ...

Given distributions with closed-form quantile functions, since distributions are equivalently described by CDF's or Quantile Functions will we get the same parameter estimates from either form of a ...

In logistic regression, when we look at Z-values or p-values, are we making an assumption that statistics or coefficients of a predictor follows normal distribution? Null Hypothesis is Coeficient of ...

I have some multilevel-data-structure, where I want to regress top 10 music chart listings (dependent variables: downloads and rank) on some song characteristics (Xi). The problem for me now comes ...

I am trying to evaluate the moment generating function of a Weibull distribution with shape parameter $\tau>1$, I know that in this case it corresponds to a light tailed distribution. Basically I ...

for a study that is currently in the planning stage we are considering what kind of model would be most appropriate. We are interested in the interactive effect of a drug (vs. placebo) and hormone ...

I'm working with an asymmetric moving average model and I want to interpret the standard error of the coefficients in a similar model: I'm confused about what the standard error of a coefficient ...

I have 8 variables for which I have to examine whether they have a normal distribution or not. There are 270 observations for each variable. I've run a normality test on SPSS for each variable and all ...

Let $y_{ij}$, $i=1,2,\cdots,n_j$ be a random sample from $N_p(\mu_j,\Sigma_j)$, $j=1,2$. Let $$\overline{y}_j=\frac{1}{n_j}\sum_{i=1}^{n_j}y_{ij} \hspace{2mm} \mathrm{and}$$ $$S_j=\frac{1}{n_j-1}\sum_{...

When working with imbalanced datasets, should one do one-hot encoding and data standardization before or after sampling techniques (such as oversampling or undersampling)?

I´m trying to deduce the profile log-likelihood function in "Rule-Based and Case-Based Reasoning in Housing Prices" (page 14) by Gayer et al. (2007). Given is: $$\mathbf{y}=\alpha \mathbf{1} + \...

I'm trying to classify/cluster subjects according to 4 features in two classes: healthy and sick. Two things to know: I know the labels/classes of each subject + I only have 40 subjects (in total: ...

The question concerns two variables with scores from a personality test, Ptest1 and Ptest2 with values from 60 participants from each variable. So how I can convert these two variables into a new ...

I've performed single cell analysis in which each gene represents a feature to cluster upon; there are about 20,000 genes expressed across all the cells in the dataset. I use the top 1500 or so ...

I understand the title is too generic. I tried to look for similar questions and although there were a few that were seemingly about the same issue, either they provided answers in the negative or had ...

could you guys point me in the right direction to where I can find papers or information about the state-of-the-art performance for the CNN prediction (feed-forward) algorithms? I'm currently ...

I am trying to find the top 2.5% of my data set. In other words, do a 97.5 confidence. The reason is I want to get rid of the top 2.5 % from my data set. I ordered my data from smallest to biggest ...

I work for a manufacturing company where robust databases and data integrity have not always been a priority. I have a very messy and finite list of 13,102 tool descriptions. I need to find out how ...

Let $X_1,X_2,\ldots,X_n$ be i.i.d. RVs with $E(X_{i})=0$ and $V(X_{i})=\sigma^2$, $\sigma <\infty$.Is it possible to find real sequences $a_{n}$ and $b_{n}$ such that $a_{n}(\bar{X}^3_{n}-b_{n})$ ...

I'm new to Support Vector Machines and I've been trying to get into the underlying math (instead of just using Scikit Learn or something like that). I understand the math behind it up to the point ...

I'm working with some fairly large LP problems in R and running into very slow computation times. I'm using the 'lp_solve' solver R wrapper ( through lpSolve and lpSolveAPI packages ), and found the ...

I have built a neural network using Windows Processes. I started off with only two features, the file path with parent process, and the file path with child process. I am slowly adding features for ...

I ran linear mixed model for multiple response variables using the R package, nlme. ...

So after k-means has assigned labels to each data-point. I want to map these labels to the closest pre-defined labels. I have 6 types of pre-defined labels on all of my observations. So the data ...

I cant seem to move further with this Venn Diagram, can someone help me identify what I am doing wrong. The explanation is a follows: A group of 138 people: 39 had at least one tattoo 92 had ...

I am trying to understand how shapiro-wilk test function. So far, I have come accross the following links: How are the values in the Shapiro Wilk weight table calculated? which explains how to ...

I have a data frame with five dependent variables (Yi) and 15 independent variables (Xi). my goal is to run a model that contains all possible combinations of Xi to explain each of the Yi. I think I ...

I'm looking for a suggestion for ways/methods either in r or SPSS to answer how the variance in one set of variables could attribute for the variance in another set of variables. Here is the key ...

When I use the loglik function in R I get numbers like 1002, 1040, -4000, etc. What do these numbers represent? I was looking into maximum likelihood and it's logarithmic counterpart and I understand ...

I have a dataset for gym memberships over 5 years. I'm trying to predict what is causing people to cancel their policies. Variables I have include age, gender, income, locations... all demographical. ...

I want to understand these two methods. I know the second one is a standard one. Can I use the first for the same purpose? Please give reasons. Also, what are other ways to normalise data? Some ...

This is a question about reducing bias in models, in the cultural sense of unfair discrimination. I'm aware that adding features to a model will tend to decrease its statistical bias. The models I'm ...

Is there a way to make plots with emmeans (precious lsmeans, while including the pairwise contrast assigned with ...

Given I have the following dataset and the data is transactional is nature. ...

I have a dataset of user written reviews. What I would like to do is to cluster similar reviews together. I have already trained a word2vec model on vocabulary of 50000 words, and I have updated my ...

I have a 2 years worth of Monthly adjusted data. From that I am taking past 6 months of data to calculate mean and standard deviation. My Six months worth data looks like this, ...

I'm trying to get an estimate of the error in my sample standard deviation (not a statistician at all, hope I'm using correct terminology). The timeseries is normally distributed and follows an AR1 ...

I read through some literature online and did some investigating on my data and the type of scales my data represents. In my data set, I have my independent variable called ASA status (this is a ...

can anyone help me with what this R (package lavaan) syntax? I got a question: Is it correct that a kind of nested multiple mediation is tested with this code (X = "predictor", XM1 = "predictor 2" in "...

I have a dataset contains both numerical and non-numerical columns. I want to use PCA, is there any way to handle both?

I have a few very large and quite "dirty" datasets. Primarily, there are lots of NA's. Because the datasets are so large I would like to use LASSO, to aid me with variable selection. If I would ...

The k-medoids algorithm is a popular distance-based clustering algorithm. It uses a heuristic algorithm to assign samples to clusters based on centroids, which are itself samples. It's cost function ...

I want to use MCMC for generation, but condition the model based on some contextual parameters. Let us consider the following example. ...