All Questions

I have a query regarding contrasts of posterior predictions. I have generated three sets of predictions from a model using data from animal orientation experiments. The data were modelled according to ...

I am beginner in Stata and any help would be appreciated. I am trying to work with the stata placebo command provided in the 'help synth' page and then visualize it as done by Abadie and others. The ...

MONT 2010 2011 2012 2013 2014 Jan 8340 7124 6431 5231 4069 Feb 8566 9121 5629 6119 4505 Mar 6560 6214 6354 6235 6165 Apr 8212 7458 6614 5178 ...

Randomlyselectedpredictors by random forest

I have an LSTM model and I want to compute the uncertainty of my model. What formulas for uncertainty can I use? If there is an implementation in python, that'd be great.

I have plotted the probability density function of some data, using a Kernel Density Estimator. Both the data, and the code I am using can be found here I want to plot the confidence interval of ...

I am trying to build a Multi-classification neural network from scratch to learn the Fashion-MNIST dataset, which I got from Kaggle. Here is a link to the dataset. Here is a link to my code. I have ...

I have 2 dataset collected with different data collection methods (very large datasets). I use the same classification algorithm on both dataset and get a greatly improved result for one compare to ...

yi=B1*x1i+B2*x2i+ui I've tried many ways to prove B1 is consistent when we know x2i is observable and is uncorrelated with x1i.

We have a small(n = 19) non-randomized pilot clinical study in which we compare two types of surgical procedures on various outcomes. The choice of which procedure was to be performed depended ...

Suppose I have $X$ such that $P(X=1)=\pi$ and $P(X=0)=1-\pi = q$, and $Y$ such that $$P(Y=1|X=1) = 1-q(1-\rho)$$ $$ P(Y=0 | X=0) = 1-\pi(1-\rho),$$ then I can simulate $X,Y$ such that their ...

I built a ZI model and it is producing predicted values that are from a very small range when compared to the observed values. Plus it does not produce any zeros. See the fitted vs. observed graph ...

I'm conducting some research where I need the critical values of the one-sample Kolmogorov-Smirnov distribution. I've found a number of tables online, but the answers from these tables seem too high. ...

When the sample size is large, the results tend to be statistically significant even when there is a small difference between the means of two groups. however, sometimes we see the results are not ...

To control the number of low-fat (defective) oil cans, an $np$ control chart is used, $CL=3$, control limits distant at ± three standard deviations from the center line and $n=150$. How at least ...

I am using R/Python diff() operation. e.g., https://docs.scipy.org/doc/numpy-1.14.0/reference/generated/numpy.diff.html I would like to know if there is a ...

initially as far as I have dug up on internet and books I have seen that Box-Cox transformation may not normalize data as we wish. Besides, log-likelihood function is maximised with $\lambda$ variable ...

0 I'm looking into a project that generates text using LSTM. The common approach to this is having the network output a distribution which you use softmax on to get the most probable word. This ...

Lets say patients in a trial were followed for over 10 years, but there are no events in either treatment or control group after 5 years (the survival curves are flattened after about 5 years). When ...

Consider this question, Suppose $X_1, X_2, . . . , X_n$ is a random sample from an exponential distribution with mean $\lambda$. Assume that the observed data is available on $[X_1], . . . , [X_n]$,...

I am not sure how the results of this study should be analysed given its design. I have searched everywhere for this info on this TYPE of experimental design and have had no luck. I don't even know ...

Suppose, after ACF and PCF investigation, I see my data has strong seasonality. I do both additive and multiplicative time series decomposition, just to check it results. I am not interested in ...

Wikipedia defines p-values as (The probability of obtaining a test statistic) equal to or more extreme than what was actually observed For starters, usage of extreme there is subjective. To make ...

I have a GLM in OpenBugs with a Poisson distribution, I've run the model and had convergence on six explanatory variables. What I'd like to do is for each of these variables, make a plot for the ...

While 2nd order methods have many advantages, e.g. natural gradient (e.g. in L-BFGS) attracts to close zero gradient point, which is usually saddle. Other try to pretend that our very non-convex ...

I am trying to investigate if there is a relation between Occupational Therapy (OT) dosage for stroke patients and patient recovery. I have separated the patients into 2 groups by the amount of ...

Where could I find a chart or almanac on ticket sales for Six Flags over Georgia to go with the family on line less days?

So, I have been trying to play around with NLP recently and decided to work on a project involving Emotional Analysis. I have been following this particular research, http://www.cse.yorku.ca/~aan/...

Suppose $X_t$ is a stationary mean-zero time series with spectral density $f_X(\omega)$. Note: $X_t$ is not necessarily a white noise. Find the spectral density of $Y_t$ where $Y_t = aY_{t-1} + X_t$ ...

I just came across a biokinesiology paper that used some Machine Learning methods, but I think there is a flaw in their methodology. The authors had data on stroke patients and used Lasso regression ...

I'm looking for recommendations of books about Pricing Analytics (non- life insurance and using R or Python, if possible). I want the big picture, from scratch I appreciate your help.

When I fitted the nonlinear regression using the openbugs, and calculated the 95% credible interval of the coefficient through the high density interval, I found that the total number of the credible ...

I have data from 500 school children who took a test. 250 of the children have a certain type of disability (group A). Each child in group A was matched to a child on the basis of age, gender to a ...

How to add column in a table without taking table offline. I was asked this in an interview and didn't have an answer. Can you help.

How would you see a trend a sales in years even there are fluctuations? Please provide answer with details.

My understanding of the Probabilty Density Function is that they evaluate to 0 at a particular point . So if we have some i.i.d points $x_{n}$ from a Normal distribution and we write : \begin{equation}...

I have written a logistic regression routine using the Newton-Ralphson algorithm in VBA for use in a class that I teach which uses primarily EXCEL. I want the algorithm to test for complete and quasi-...

Let's say I have three tables: patients, samples, and mutations. The patients table has unique rows, each with a unique patient_id. The samples table has unique rows, each with a unique sample_id, ...

I would like to run a GLMM with multiple random factors using the function glmer in package lme4. I have a dataset on marine debris like this: count density: numeric year: categorical, two levels ...

Given a univariate time series, what are common / best practice ways to detect "ramp up" or "ramp down" in a time series over an extended period of time? For example, given a daily time series of an ...

Let $X_1, ..., X_n$ be iid $f(x; \theta, \lambda) = \dfrac{\lambda e^{-\lambda x}}{1-e^{-\lambda \theta}}$ for x $\in [0, \theta]$. I am asked to find I want to find A minimally sufficient ...

For two groups A and B that consist of n and m individual samples. Each individual sample has a unique i-dimensional probability density functions (PDFs). I had the following questions: How can one ...

I am learning Maximum Likelihood Estimation. per this post, the log of the PDF for a Normal Distribution looks like this. let's call this equation1. according to ...

When running one-way ANOVA I did not have equal variances, so I log transformed the data and reran ANOVA with equal variances. Do I use these new p-values from Tukey's post-test on my graph showing ...

Let $X_1, .. X_n$ be iid Bernoulli($\theta$). I want to estimate $\lambda = \theta(1-\theta)$, usin $\delta$ (unbiased estimator for $\lambda$) where $\begin{cases} \delta = 1 & X_1 =1 \...

There was a question about p value interpretation and one of the comments made me wonder whether there is some basic misunderstanding I have about p values. I wrote "you can discard the null ...

I bumped into a problem that dazzles me very much, I can't believe it's actually happening. I trained an elastic net using last version of scikit-learn function ElasticNetCV and a 4 folds CV repeated ...

For PDF and CDF f(x) = 1- 0.5 x, 0 Find the inverse F^-1(x) given uniform distribution over (0, 2) Use your answer to plot histogram on STATA Yes. Draw a random sample of 123 people and plot a ...

Given the following AR(2) process: $y_{t} = \phi_{1}y_{t-1} + \phi_{2}y_{t-2} + u_{t}$ I need to prove that the sufficient condition for this process to be stationary is $\phi_{1} + \phi_{2} < 1$....

If $X_{1},X_{2},\ldots,X_{n}$ are independent random variables with common mean $\mu$ and variances $\sigma^{2}_{1},\sigma^{2}_{2},\ldots,\sigma^{2}_{n}$. Prove that \begin{align*} \frac{1}{n(n-1)}\...