# All Questions

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17 views

### Measuring the performance of a binary classifier

I've build a binary classifier (text classification for spam non spam emails) based on DT classifier using scikit learn and I am training the classifier and testing different test sets 'sorted ...
0answers
14 views

### What preparation do I need to understand mathematical statistics research papers? [on hold]

I have an undergraduate degree in mathematics and statistics and a masters in finance. But my preparation is not adequate to read research papers in mathematical finance and statistics. I want to ...
0answers
11 views

### Hypothesis testing on SVM using parameters

1. Introduction I am working on a multi-class classification problem by using a ONE-VS-ALL classifier. I have no problem what so ever with the approach. I just wanted help in how can we interper ...
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18 views

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27 views

### output is a factor … how do I model it

If my input is numeric and my output is continuous I can use linear or nonlinear models. I can split the inputs by factors if an input is a factor. If my input is numeric and my output is boolean I ...
0answers
24 views

### How to achieve requirements for a PhD in medical statistics when my background is only medical? [on hold]

I don't know if this is the right place to ask this question. I am a doctor. I want to apply for a PhD program in medical statistics. These programs often require calculus and linear algebra degrees. ...
0answers
10 views

### Analysis of classification result

Assume you observed a system for 24 hours and collected data points each minute (each data points contain some host information like cpu_usage,... All elements are numeric). Also, there is a trained ...
0answers
17 views

### How to derive conditional expection for a linear combination of independent random variables

Suppose we have the simple set up $Y = \alpha X + \epsilon$ Where $X$ and $\epsilon$ are both mean zero, variance one and independent. $\alpha$ is a constant. Trivially, $E[Y|X] = \alpha X$. By ...
1answer
19 views

### When to use robust methods and how to report them in a paper?

Wilcox in his package WRS in R software managed to provide easily accessible robust techniques to conduct usual hypothesis testing like t-test, ANOVA etc. I've ...
0answers
11 views

### What statistical test can I use with 3 replicates and repeated measurements?

I'm doing analysis on data from an ecological field study. I have fields (n=12) of different age. I treat age as a factor (age class) having 4 levels (1,3,5,and 7/8 years old). Hence the number of ...
1answer
26 views

### Data Mining for a Continuous Target

I have 50 variables, most of them numeric, a few categorical, and my variable of interest is continuous. In addition, I have something like 300,000 observations. I am looking for a way to predict the ...
0answers
9 views

### First Differences vs Within Transformation

First differences and the within transformation / demeaning are the popular approaches to estimating a fixed effects panel data model. I am interested in how the two techniques affect the properties ...
0answers
5 views

### Haplotype Inference using MCMC

A 2001 paper on Haplotype Inference using MCMC (http://stephenslab.uchicago.edu/assets/papers/Stephens2001.pdf), refers to the conditional distribution of a future sampled haplotype, given a set $H$ ...
0answers
20 views

### How to correctly standardize Poisson distriubuted variable? [on hold]

Is there any specific way how to standardize variable which comes from Poisson distribution? I've found that one way is the you can use same approach as for Gauss distributed variable. I've also ...
0answers
9 views

### How to transform the LDA model to see the topic evolution in chat content?

Now I have a data set with about 13,000 lines, including the date, sender, chat content in a public server. The data set covers about ...
0answers
4 views

### How to implement a SVAR with sign restrictions

I am trying to estimate a bi-variate sign-restricted SVAR with daily oil and stock prices and two shocks (demand and supply). The ultimate goal is to explain how much of the recent fall in oil ...
0answers
13 views

### If statement doesnt work [on hold]

When I run my code, then nothing happens. My data isnt modified as it should. My code: ...
0answers
47 views

### Why is the MEAN taken in Simple Linear Regression?

Question Why take the mean of the squared residuals? wouldn't it be simpler and produce the same result ( parameters $\theta_0$ and $\theta_1$ ) if you just minimised the sum of the square ...
0answers
3 views

### What kind of pooling with non ReLU non-linearities?

in a Convolutional Neural Network it is customary to have a ReLU, then max pooling. If we would have a symmetric non-linearity, e.g. max(w_1 x, w_2x), would it make sense to have a max absolute ...
0answers
12 views

### Directed Acyclic Graph Neural Networks,

I have a question, and I cannot actually find out the "right words" to search for it in Google for myself. So, I thought perhaps somebody from here could either give me the answer directly, or maybe ...
1answer
33 views

### $f(x)$ is an increasing function. $\langle X_1 \rangle > \langle X_2 \rangle \Rightarrow \langle f(X_1) \rangle > \langle f(X_2) \rangle$?

Let $f(x)$ be an increasing function. Consider two random variables $X_1$ and $X_2$, with different probability distributions, such that $\langle X_1 \rangle > \langle X_2 \rangle$. Does it follow ...
1answer
32 views

### Multiple Correspondence / Correlation Analysis

I'm a little bit new to statistics, so I'm not sure what I really need. I have a table like the following with some categorical/nominal values (like Gender and Age Group) and a ratio scaled value ...
0answers
9 views

### How to create a data subset by using a dynamic column name / variable? [on hold]

Why are dynamic column names not working in brackets? ...
0answers
18 views

### How can I find the probability of the following?

I need to find $\mathbb{E}_d[\mathbb{P}\left\{X\le\mu\right\}|\hspace{1mm}d]$ with ...
0answers
6 views

### What is the difference between Bayesian seasonal adjustment and other types?

I need to learn this for a new task I have been allocated but it has been a few years since I studied maths! I have some books on time series and have read a few papers on it and I understand time ...
0answers
14 views

### LS-SVM time series forecasting

I'm trying to forecast a time series of air passengers using LSSVM with the help of the LS-SVMLab toolbox v1.8 from http://www.esat.kuleuven.be/sista/lssvmlab/, specifically the NARX model function. ...
0answers
19 views

### Validity of Statistics in Data Mining

While I was going through Oracle Data Mining, found a interesting statement. https://docs.oracle.com/database/121/DMCON/process.htm#DMCON115 Data Mining and Statistics There is a great ...
1answer
17 views

### Forward-Backward Algorithm explanations

I am studying the Forward-Backward Algorithm from HMMs and the forward-backward algorithm by Ramesh Sridharan I don't understand how to get $(1,3,4)^{T}$ in the example below. Could someone help to ...
0answers
25 views

### Can we solve multiple linear regression using simple linear regression solver?

Suppose I have a blackbox function that solves simple linear regression. Can I use this function to solve "multiple" linear regression? The blackbox computes the slope and intercept in a simple ...
0answers
15 views

### What to do with non-normality and heterogeneous variances in Two-Way ANOVA when transformations do not work?

I'm conducting a Two-Way ANOVA with my two factors being Sex and Cohort. I have data from two cohorts of subjects, with each cohort consisting of males and females that were measured on one response ...
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21 views

### What is the correct formula for Linear Regression Forecast? [on hold]

I would like to know the correct Linear Regression Forecast formula. I tried different books and sites, but haven't found any reasonable answer. Are the Linear Regression & Linear Regression ...
0answers
13 views

### Statistical analysis for interaction of genes in multisamples

Say I have 120 human individuals. I have done gene-gene interaction in those individuals and found the frequency of all the interacting genes as shown in the data below. I want to do some analysis to ...
0answers
5 views

### Deconvolution - two transfer functions applied to the same signal

I'm observing two timeseries, $\hat{h_1}$ and $\hat{h_2}$. I believe that both are products of convolution of the same underlying signal $f$ with a two different transfer functions, $g_1$ and $g_2$, ...
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6 views

### Estimating Sailboat Wind Measurement Calibration Error

Sailboat performance is always judged relative to the wind. The optimal approach to sailing the boat is different in light wind than in heavy. So, knowing the wind helps by setting accurate ...
0answers
6 views

### JAGS: Cannot invert matrix: not positive definite

I am trying to model a response Y (count; range: 0-230) against a single predictor X (continuous, rescaled and centered to lie between -0.18, 44.8). The parameters of the relationship between X and Y ...
0answers
8 views

### Train, Validate, and Test partition for cross validation [on hold]

I would like to split data into three partitions for k-fold cross validation. However, the Matlab function 'cvpartion' only produce two outputs which are train and test. Do you know any way to work ...
0answers
18 views

### I need to prove this relation [on hold]

show that Var(y)= 1/N{σyy [0] + 2 (_L=1^(N-1))∑(1-((|L|)/N))σyy[L]} Where ; σyy=Auto co variance function Var(y) = variance of y
0answers
14 views

### Conditional statements in Winbugs

I am using Winbugs for bayesian estimation. I have a categorical data that consisted of the values:1,2,3. Here is what I have: ...
1answer
19 views

### Difference between sample mean and sample median in estimator [on hold]

I need the main difference between sample mean and sample median in estimator
0answers
18 views

### how to proof for unbiased estimator or consistent estimator [on hold]

1.I need to proof this question for me. show that a single sample of N observations of a white noise is an unbiased estimator of the mean, but not a consistent estimator.
1answer
20 views

### Binary logistic regression in R - assistance with determining odds of a predictor at different levels

I have performed a binary logistic regression in R with whether or not a sportsperson was re-contracted or not as the DV. My final model is as follows; ...
1answer
28 views

### What should be the correct result of this product $(Y-XW)^T(Y-XW)$

i usually come across this equation and I am not able to understand it entirely, here X, W and Y are matrices of size N*D, D*1, and N*1 resp. $(Y-XW)^T(Y-XW)$. As per me it should be equal to ...
0answers
16 views

### probability of side A in tossing 3 times of 4-sided dice [on hold]

Q: Find the probability of one side (let's call it A) showing up at least once in three tosses of a 4-sided dice. I get different answer if I do 1-P(no A's) versus P(one A) + P(two A's) + P(three ...
1answer
28 views

### Tool for implementing neural networks [on hold]

I am doing a project on offline signature verification (not classification) using artificial neural networks. Which tool/api should i use? Also mention the options i have with their strengths.
0answers
15 views

### Random effects in GAM [on hold]

I am now trying to use random effects in GAMs developed by Professor Simon Wood. Prof Wood uses s(...,bs="re") to account for the random effects. Random intercepts models or random slopes models are ...
1answer
14 views

### How to calculate the probability that a scalar data point maps to a class?

Suppose that I have the following data set that maps students' test score to the class in which the student belongs: ...
1answer
16 views

### Combining different normality transformations for Fisher's method

I have 2 data sets that are applicable to Fisher's method. One has a p-value of 0.07 and the other 0.15. Neither sets were normal or homoscedastic. The first satisfied the ANOVA assumptions only with ...
0answers
15 views

### How can I approximate a pdf knowing the estimated CDF in R?

I have an estimate of a CDF in R (nonparametric) and I need to compare this distribution to another one by Kullback-Leibler. In order to do so, I need to find the pdf of this random variable. What is ...
1answer
18 views

### What are the recent real life use or applications of the Cauchy Random Variable?

We have a short assignment on the described question and I already have gone through a lot of trash results from Google. I can't seem to find any. I don't know where else to post this question. ...
0answers
7 views

### Multiple time series - class of problem with agents and events?

I'm working on a prediction problem and struggling to find applicable resources (articles, tutorials, papers) that address this class of problem. I'm assuming the info is out there and I'd love to ...

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