instruction stringlengths 9 38.7k |
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I've been running some power simulations for a one-way ANOVA in R, and my problem is that the results from the simulation doesn't match the result from g*power or pwr.anova.test from the "pwr"-package. As an example, let's compare simulated power to analytical power using these values:
group_size <- c(40,40,40)
means <... |
I have list of proteins with their feature values. A sample table looks like this:
...............Feature1...Feature2...Feature3...Feature4
Protein1
Protein2
Protein3
Protein4
Rows are proteins and columns are features.
I also have a list of proteins which interact as well; for example
Protein3, Protein4... |
I am looking for some libraries in R that can do incremental learning (also called online or sequential learning). The use case of such learning in comparison to traditional batch methods would be to process large amounts of data. Such practices include streams and data from sensors, where it is not feasible to use alw... |
I have a sample of 100 items, each associated to a random variable for which I can compute expected value and variance: $X_1, X_2, ..., X_{100}$. From these, we can define the mean $\overline{X}=\frac{1}{100}\sum{X_i}$. I'd like to test the hypothesis $H_0:\mu=0$, (where $\mu$ is the true population mean from which the... |
Is there any function for $M$-estimation in multivariate linear regression model in R. I can estimate the $\beta$'s in my model by using the rlm() by rewriting the $y$-variables into one column but, I would like to use one function to get the $\beta$'s.
|
Consider approximating the following integral:
$$
\mathcal{Z} = \int h(x) \pi(x) dx
$$
Where $\pi$ is known only up to a normalizing constant, that is, $\pi(x) = \hat{\pi}(x)/\mathcal{Z}_\pi$. We can simulate $\{x^{(i)}\}_{i=1}^m$ from an appropriate proposal distribution $q$ and use the ratio importance sampling esti... |
General theories would be great. My specific problem is I'm trying to find a specific portfolio of all the stocks in the market. The possibilities are huge because I need the stock combination(itself massive) and weights for each stock(even larger than the quadrillion combination). To make matters more complicated, I'... |
I'm a biology PhD student dealing with ordinal data (scoring of a medical effect: 0–3 points) for the first time and I'm looking for information regarding differences in treating ordinal numbers in
calculating Mean, Median, SD, SEM etc.
performing significance tests between two ordinal datasets
calculating correlation... |
I have a question about how to correct standard errors when the independent variable has correlation. In a simple time series setting we can use Newey-West covariance matrix with a bunch of lags and that will take care of the problem of correlation in the residuals. What does one do in a panel data setting? Imagine ... |
I am using the MATLAB code for Rasmussen & Williams' book Gaussian Processes for Machine Learning.
How can one incorporate prior knowledge in Gaussian process regression? Say, that the variance in one dimension of a two dimensional vector is greater. Is it only by considering the parameters of a normal distribution, or... |
Can someone show me why for a distribution function $F$ on $(0,\infty)$, $0 < y \leq x$, the following holds:
$\frac{F(x)-F^{*2}(x)}{\overline{F}(x)}=\int\limits_{0}^{x}\frac{\overline{F}(x-t)}{\overline{F}(x)}dF(t)$
Edit: $F^{*2}$ stands for the convolution of $F$ with itself:
$F^{*2}= F \star F = \int\limits_0^x F(... |
I'm an enthusiastic single developer working on a small start-up idea. I reduced a corpus of mine to an LSA/LDA vector space using gensim. Now I have a bunch of topics hanging around and I am not sure how to cluster the corpus documents. I see that some people use k-means to cluster the topics. Can someone please elabo... |
I'm relatively new to statistics, and understand that my question may be completely misworded. I am testing my own algorithm versus another. While the outputs are not identical, I want to show that the differences are "statistically insignificant." How can I quantify this, to make my point?
|
I recently ran an experiment assessing the impact of three system factors (factor A; factor B; factor C) on user attitudes (4-item scale). Each system factor had two levels (high vs. low). As a result, my experiment had nine conditions: eight treatment conditions (reflecting the 2x2x2 design) plus one control group. Su... |
I've come across a scenario where I have 10 signals/person for 10 people (so 100 samples) containing 14000 data points (dimensions) that I need to pass to a classifier. I would like to reduce the dimensionality of this data and PCA seems to be the way to do so. However, I've only been able to find examples of PCA where... |
I am wondering if I can use the results of EOF to "predict" the EOF loadings of a second set of data?
I have a data set $X$ that consists of sampled light spectra (each column represents a sample and each row is the amplitude of the spectra at a given wavelength).
So I first construct a covariance matrix of my data:
$... |
I would like to understand whether the output of an algorithm I developed agrees with the ratings of external observers. The number of observers is 10 and each of them rated on 2 3-point-Likert items 10 stimuli. The algorithm provides one measure (a real number) for each stimulus.
I am thinking about the use of intrac... |
Right now, I'm doing my thesis which use multilayer perceptron learning method to train a model. What I learned from my class is the purpose to partition the data which can be separated into 3 group
Training dataset - This set is to train the model.
Validation dataset - This set is to find the best model parameters.
T... |
Are there any games that get the player "think like a statistician"?
For example, lightbot gets you to "think like a programmer" (in a very basic way). Are there any games - designed for entertainment or teaching - that can help get one comfortable with basic concepts like correlation, p-values, least squares, variance... |
In Section 4.2 of the paper by Boucheron et al., the authors argue that the minimizer $f^*$ of the cost functional
$$A(f) = \mathbb{E}\{\phi(-Yf(X))\}$$
is such that the classifier $g^*$, constructed from $f^*$ by
$$ g^*(x) =
\begin{cases}
1 & \text{if } f^*(x)\geq 0 \\
-1 & \text{otherwise}
\end{cases... |
Consider a multinomial $2\times 2$ table $\begin{pmatrix} x_{11} & x_{12} \\ x_{21} & x_{22} \end{pmatrix}$ with theoretical probabilities: $$\begin{pmatrix} \theta_{11} & \theta_{12} \\ \theta_{21} & \theta_{22} \end{pmatrix}.$$
Let us call $p:=\dfrac{\theta_{12}}{\theta_{11}+\theta_{12}}$ the "false positive" propo... |
I have a linear model of a dependent variable, $y$, with two predictor variables, year and site, and their interaction, with year being numeric and site categorical.
The main effect of year is not significantly different from zero, with an estimated value of 0.02312 for the $y$ on year slope.
Some of the year by site i... |
I was trying to fit one time-series data (without replicates) using regression model.
The data looks like follows:
> xx.2
value time treat
1 8.788269 1 0
2 7.964719 6 0
3 8.204051 12 0
4 9.041368 24 0
5 8.181555 48 0
6 8.041419 96 0
7 7.... |
I am trying to sample the Gaussian markov random field or say multivariate gaussian distribution with some spatial correlation given by the precision matrix Q.
Here is the algorithm that I am using
Compute the Cholesky factorization Q=LL'
Sample z ~ N(0,I)
Solve L'x = z
where x is the samples obtained.
I have a grid ... |
If I fit my data with something like lm(y~a*b), in R syntax, where a is a binary variable and b is a numeric variable, then the a:b interaction term is the difference between slope of y~b at a = 0 and at a = 1.
Now, let's say the relationship between y and b is curvilinear. If I now fit lm(y~a*poly(b,2)), then a:poly(b... |
I have a sample data for a spatial grid of size 20x20. I need to plot the correlogram of this grid of data to see how much they are correlated. Currently I have 400 data points for the 20x20 grid cells, one for each cell. How can I compute the correlogram to see the correlation?
|
This is Statistics 101, but I'm not a statistician and so can't seem to find the right technical jargon to google.
My company collects data at discrete points through time. Today's datapoint is positioned somewhat differently to the others, and so we're having a debate about whether this is an accident of chance or ind... |
I can't seem to find what this does online. Does is create a random distribution?
|
I have data which looks like this. As you can see the data is symmetric and its not exactly a distance matrix. They are log odds ratios. And the diagonal values are higher than non-diagonal elements.
I want to know if normal clustering techniques could be use for such a scenario. When I looked online, all the clusterin... |
I am interested to learn about cognitive robotics and its application in situation assessment using natural language processing esp monitoring of human activities/disaster management.The processing would involve data visualization techniques. Can anyone suggest what is the starting point,which books to follow,the progr... |
I am interested in understanding the graph plots we get after running lm() command (for linear regression) in R like, for example
lm.mod1 = lm(y ~ x1 + x2)
I then get the do the summary by:
summary(lm.mod1)
I get the result as:
Residuals:
Min 1Q Median 3Q Max
-750.32 -160.54 -49.83 115.83 2923.7... |
Random Forests (RFs) is a competitive data modeling/mining method.
An RF model has one output -- the output/prediction variable.
The naive approach to modeling multiple outputs with RFs would be
to construct an RF for each output variable. So we have N independent
models, and where there is correlation between output ... |
I'm currently trying to evaluate a model of metabolism which aims to predict whether deleting individual genes will cause a growth defect (there are ~850 genes in total). I know from experimental data which genes show slow growth, so I'm mainly judging the model on what percentage of genes it correctly predicts. Ther... |
I was hoping you could provide some information on how one should interpret and present group level coefficients and degrees of freedom in a mixed effects (in my case: logistic) model. I'm fully aware of how we understand them in the classical sense, certainly in conventional OLS and logistic regression models. Howev... |
Context: say I am trying to determine the concentration of a chemical, so I take known concentrations of the chemical and make a standard curve (6 measurements per standard) then measure my unknown 6 times.
Here's what I can do: I can use linear regression to determine confidence limits for the concentration of each i... |
Note that for a homogeneous point process the density is just a number, while for an in-homogeneous process it is a function. In addition, how can I distribute that function on a larger study region than the initial points?
Update 1:
Suppose the region a is given with intensity functional to x and y coordinates. It is... |
I'm currently working on a project measuring willingness to pay (WTP) for a particular product. The data we are collecting are continuous variables denominated in the local currency. One thing we are interested in is the "demand curve" for this product, expressed as the fraction of respondents willing to pay a partic... |
I am using the Metropolis-Hastings algorithm for phylogenetic inference. To do so I would like to draw the substitution matrix Q from the generalized time-reversible model.
To do so I need proposal distributions for the stationary distribution and the 6
substitution probabilities. For the stationary distributions I wo... |
First I have to apologize for any uncorrect naming or categorisation of my question, as I am an electrical engineer rather than a mathematican.
I have a simulation that outputs for a given number of input parameters one output value. As the simulation is pretty complicated, I don't know the statistical connection betwe... |
I'm trying to fit a multilevel model for a repeated measures design with three levels:
Subjects - conditions - trials. Each subject passes the test in two conditions, and there are 21 trials in each condition. Each trial is expected to be correlated in some manner with the previous and following trial.
My problem is t... |
What's the definition of a symmetric distribution? Someone told me that a random variable $X$ came from a symmetric distribution if and only if $X$ and $-X$ has the same distribution. But I think this definition is partly true. Because I can present a counterexample $X\sim N(\mu,\sigma^{2})$ and $\mu\neq0$.
Obviously,... |
I've got a stochastic variable $X$ which takes the values in $\{0,1,2\}$ with some unknown probabilities. I want to know the distribution, and can sample $X$ as many times as I want to. How many times will I need to sample to get some specific confidence interval?
(For instance, 99% sure that the estimated probabilitie... |
I am curerntly running PCA for returns series of 50 stocks for 524 observation. I have completed following steps like I have computed covariance matrix, got the loading for each of them and also respective scores for all 50 stocks. There are 20 component explaining 80% variation.
When we get final scores for example p... |
I have a set of data $Y \in \mathbb{R}^n$ and a set of $k$ factors $\{F_1, ..., F_K\}$ with $F_i \in \mathbb{R}^n ~ \forall i$.
I would like to perform a factor analysis which consits in finding $\beta \in \mathbb{R}^k$ such that:
$$Y_t = \alpha + \sum_{i=1}^k \beta_i {F_i}_t + \varepsilon_t$$
I believe that I would n... |
I am doing some work on the effects of collinearity on different types of model (OLS, binomial logistic, ordinal logistic, multinomial logistic and maybe others). I have found the perturb package in R, which will be very useful for this. This package shows how small changes in the data affect the parameter estimates of... |
I studied the standard econometrics textbooks about panel data, but most textbooks only mention the difference between balanced and unbalanced panels. The advantage of having balanced panel data is not usually explained. I would like to know: What is the advantage of having a balanced panel? I believe unbalanced panels... |
This might be a simple question but I am unable to find a solution on the web. I would like to measure variation of some numerical data. What is the minimum number of values I should use for measuring their standard deviation or coefficient of variation? Basically my plan is to derive groups from a set of performance m... |
I am performing a Mixed between subjects Anova where I have multiple time points that subjects have completed a measure at.
The within subjects factor is time.
The between subjects factors include gender, ethnicity, refugee status and English language.
My two questions are
Combined or separate ANOVAs: Is it possi... |
I am asking to find out why a factor may become non significant after I define the nested design. The following are the two aov analysis in R.
Obs (subject #) is the within subject factor and stim3 & label (1st & 2n stimuli manipulations) are the nested within subject. stim3 & label are nested within obs. The analysis... |
$F$ is the distribution function of a positive random variable.
Why does the following hold for every $x \in (0,\infty)$:
$F^{*2}(x) \leq F^2(x)$, where
$F^{*2}=F*F=\int\limits_0^x F(x-y)dF(y)$
|
First, I have a question about whether the Poisson distribution is "stable" or not. Very naively (and I'm not too sure about "stable" distributions), I worked out the distribution of a linear combination of Poisson distributed R.V.'s, using the product of the MGF. It looks like I get another Poisson, with parameter equ... |
I am trying to create the algorithm that will tell me the good price to buy stuff and a correct re-selling price based on eBay item history.
The main variables would be the auction type (buy now or bidding), price, if the item was sold and some sort of margin that has to be made on each transaction (in percents or doll... |
I have a grid of plots (see example below) with different x axes but all the same y-axis. What is the best way to label the y-axis without being redundant? The information is in the legend, but this is not a solution.
Here are two options I am considering:
center one label on the right hand side in the same font as th... |
Possible Duplicate:
Computing and plotting a correlogram
I have spatial data for a grid of size 20x20. I wanted to know how I can plot a correlogram to see how much the data are correlated spatially.
|
I want to do power computation for testing differnce between two log normal means with R. Can you write using R code?
best wishes...
|
I'm working on a word-prediction/spelling-correction software project and I need to calculate the probability that a dictionary word is what the user meant to type, referred to as a "score". I found an article that explains how to score matches using statistical techniques, but I don't understand it 100% (I'm not stats... |
I am thinking of building a model predicting a ratio $a/b$, where $a \le b$ and $a > 0$ and $b > 0$. So, the ratio would be between $0$ and $1$.
I could use linear regression, although it doesn't naturally limit to 0..1. I have no reason to believe the relationship is linear, but of course it is often used anyway, as ... |
I'm trying to make overlaid ROC curves to represent successive improvements in model performance when particular predictors are added one at a time to the model. I want one ROC curve for each of about 5 nested models (which I will define manually), all overlaid in one plot. For example:
#outcome var
y = c(rep(0... |
Ok, I have a logistic regression and have used the predict() function to develop a probability curve based on my estimates.
## LOGIT MODEL:
library(car)
mod1 = glm(factor(won) ~ as.numeric(bid), data=mydat, family=binomial(link="logit"))
## PROBABILITY CURVE:
all.x <- expand.grid(won=unique(won), bid=unique(bid))
y.h... |
I am trying to access the GMRFlib as mentioned in the link http://www.math.ntnu.no/~hrue/GMRFsim/doc/html/. However, I think it is not available anymore. I couldn't see the tarball mentioned. Does anyone have access to it?
|
For three independent normally distributed continuous random variables X, Y, and Z (each with its own mean and standard deviation), I need a way to calculate
$P(Y \geq X, Y \leq Z)$
I know that I can do this by the following:
$P(Y \geq X, Y \leq Z) = P(Y \geq X) \cdot P(Y \leq Z | Y \geq X)$
I am able to calculate $P(Y... |
I need to prove an induction step. $X_i$ are independently distributed with the distribution function $1-F_i=x^{-\alpha}L_{i}(x)$ where $\alpha \geq 0$ and $L_{i}(x)$ is regularly varying (If the limit $g(a)=\lim\limits_{x\rightarrow\infty}\frac{L(ax)}{L(x)}$ is finite and nonzero for $a >0$, then L is regularly varyin... |
I'm fitting a Bayesian HLM in JAGS using k-fold cross-validation (k=5). I'd like to know whether estimates of parameter $\beta$ are stable across all folds. What's the best way to do this?
One idea is to find the differences of the posteriors of $\beta$ and to
see if 0 is in the 95% CI of the difference. In other words... |
I am using inverse modelling software (PEST) to estimate a periodic parameter for the direction of anisotropy, $\hat{\theta}$, which is somewhere in $[0^{\circ}, 180^{\circ})$ (i.e., has a wavelength of 180°). With PEST, parameters must be defined with lower/upper bounds and an initial guess. The inverse model will the... |
Given pairs $(x_i, y_i), x_i \in R^n , y_i \in R$ we want to solve minimization
problem (logistic regression):$\min \frac{1}{2} ||w||^2 + \sum_i^{i=m}\log(1+\exp(-y w\cdot x_i))$. How to do that? I know the dual form is:
$ \min_{\alpha} D(\alpha)= \frac{1}{2}\sum_{i, j}\alpha_i \alpha_j y_i y_j x_i \cdot x_j + \sum_i\a... |
Let $0< \delta<\frac{1}{2}$. Why do we have for $X_{1},X_{2}$ iid:
\begin{equation}
\{X_{1}+X_{2}>x\}\subset\{X_{1}>(1-\delta)x\}\cup\{X_{2}>(1-\delta)x\}\cup\{X_{1}> \delta x,\ X_{2}>\delta x\}?
\end{equation}
|
Short question:
I am looking for books that deal with correlated data in a systematic and theoretical way.
Long version:
Right now I am developing approximation algorithms for time series data (more concrete I want to approximate a function $f:[a,b]\rightarrow\mathbb{R}^3$ where $[a,b]$ is a time interval). The raw ... |
Possible Duplicate:
Clustering with a distance matrix
I have a set of data which I wish to cluster.
I have computed a distance measure between each pair of data, but I am limited in that I am unable to compute a measure between each data point and an 'arbitrary' point in space. In addition, the distance measures do ... |
Are there any extensions of the James-Stein estimator for the case of dependent variables?
I've done numeric experiments with the James-Stein estimator on correlated normal variables (5-10 variables, correlation was about 0.3) and it still is better then Least Square estimator in 95% cases.
|
I am working out a book on Lebesgue measure by Bartle, and would like to see the steps that go into the construction of a proof for the following:
Show that any $\sigma$-algebra of subsets of $\mathbb{R}$ which
contains all open intervals also contains all closed intervals.
That is, $[a,b]=\cap_{n=1}^{\infty}(a-\fr... |
Is there any agreement on when to reduce data dimension before clustering in order to avoid curse of dimensionality?
My intuition is that if I have say 1000 points and data dimension is 10 then it is OK to cluster. But if dimension is 50 then it is not OK because data points become sparse and hard to cluster (as a resu... |
I'm trying to wrap my head around dynamic factor analysis. So far, my understanding is that DFA is just factor analysis plus a time series model on the scores (the loadings remain fixed). However, in the cases that I've seen, the model on the scores is just a random walk with a diagonal correlation matrix. This seems i... |
I am learning a statistical model, which includes a very large amount of parameters, which results in the risk of over-fitting. If I first learn the model parameters from the data, and then simply remove some of the parameters according to whichever criterion, would I be reducing the chance for overfitting?
On the one... |
I've followed guidelines for comparing models in Chapter 6 of Bolker's Ecological Models and Data in R, applying code used in this section to cancer count data. The models include parameters for age group (a) and birth cohort (c), and are as follows:
# Value of lambda is the same for all age groups and birth cohorts
po... |
I'm trying to generate many draws (i.e., realizations) of
a Gaussian process $e_i(t)$, $1\leq t \leq T$ with mean 0 and covariance
function $\gamma(s,t)=\exp(-|t-s|)$.
Is there an efficient way to do this that wouldn't involve computing the square
root of a $T \times T$ covariance matrix? Alternatively can
anyone... |
Can someone tell me why this is wrong:
I want to estimate the goodness-of-fit for a linear mixed effects model. I regress the fitted values against the raw values and calculate an $R^2$.
I suppose an accepted alternative would be to run the model with just the random effect and no fixed effects and compare AIC scor... |
What is the easiest way / method to compute the correlation between two time series that are exactly the same size? I thought of multiplying $(x[t]-\mu_x)$ and $(y[t] - \mu_y)$, and adding up the multiplication. So if this single number was positive, can we say these two series are correlated? I can think of some examp... |
From the R docs for hist:
R's default with equi-spaced breaks (also the default) is to plot the
counts in the cells defined by breaks. Thus the height of a rectangle
is proportional to the number of points falling into the cell, as is
the area provided the breaks are equally-spaced.
The default with non-equi-spa... |
I performed an actual scientific experiment and I was only able to collect 2 data points. I am wondering what kind of statistical method I can use to analyze the data.
I performed a similar experiment before where I was able to collect 4 data points. I calculated the mean, the standard deviation of the population and a... |
Does anybody know if any package calculates the cubic clustering criterion (CCC) index in R to aid the selection of optimal number of clusters?
|
I'm working on highly skewed data, so I'm using the median instead of the mean to summarise the central tendency. I'd like to have a measure of dispersion
While I often see people reporting mean $\pm$ standard deviation or median$\pm$quartiles to summarise the central tendency, is it ok to report median $\pm$ median a... |
i suppose one way to characterize data is by a combination of the variable types that comprises it:
Continuous/Continuous | Continuous/Discrete
-----------------------|---------------------
Discrete/Discrete | Discrete/Continuous
Each of the four cells comprising the 2x2 table just above is comprised of two... |
How would you explain intuitively what is a unit root, in the context of the unit root test?
I'm thinking in ways of explaining much like I've founded in this question.
The case with unit root is that I know (little, by the way) that the unit root test is used to test for stationarity in a time series, but it's just i... |
Lets say I run an experiment testing accuracy of hitting targets of two different sizes. I have 10 participants and 40 targets, 15 small and 25 large. I then have the number of misses for each target recorded.
So I end up with 150 small target scores and 250 large target scores. I want to see if there is a difference i... |
Let $X_1, X_2, \dotsc, X_k$ be an i.i.d. sample of a random variable $X$. I plot these in a histogram and would like to include a confidence interval for the height of each histogram bar. Do you know how to go about doing it?
|
In the context of neural networks, what is the difference between the learning rate and weight decay?
|
I have recently been involved in a project that needs me to analyze the survival time of objects. Therefore, I plan to use the rms package to build a Cox model. The problem is, since the dataset I have is so big (about 450,000 instances, and each has 9 covariables), the R environment fails to handle this. Does anyone h... |
Does the use of calibration/post-stratification imply that the sampling strategy/stratification/individual selection probabilities can be ignored altogether?
In a survey reweighting exercise, I have population totals for a complete cross-classification of four attributes: country, age, sex, and work status. EDIT: The s... |
Is it advisable to use hot-deck imputation to allow for poststratification in the presence of empty post-strata?
In a survey reweighting exercise, I have population totals for a complete cross-classification of four attributes: country, age, sex, and work status. However, the survey suffers from noncoverage: For a few ... |
Since the time variable can be treated as a normal feature in classification, why not using more powerful classification methods (such as, C4.5, SVM) to predict the occurrence of an event? Why lots of people still use the classic but old Cox model?
In case of the right-censoring data, since the time would change for an... |
Regarding the final output of PCA:
Using rotation, I'll get a loading for my 50 components, so the equation would be $pc_1=0.05*a_1+0.02*a_2+\dots+0.04*a_{50}$. Now, can I derive the value of $pc_1$ by using my last observed return for $a_1,a_2,\dots,a_{50}$?
As I looked at my data, I have f... |
We are doing an evaluation in different organizations and need to get data from workers about their work behavior. As this information is something that could get workers in trouble, privacy is an issue, so we go for anonymized questionnaires. To connect the data over time, we are looking for a participant identifier. ... |
Anyone can suggest me a nonparametric version of the intraclass correlation coefficient (ICC)? My model have the following details: two-way random effects model, consistency, average ratings as unit. I am using irr R-cran package.
thank you
|
I would like to learn about the Markovitz theory because I am going to interview at a financial firm that uses variants of it extensively.
I am looking for a resource to learn about the intuition and optimization models behind Markovitz modern portfolio theorem. Any pointer to a book or webpage would greatly help me. ... |
I was using Eviews, and I noticed that there is 'dynamic forecast' and 'static forecast' in the option. But I don't know what is the difference, would any one tell what are they? But I know that both are one-step ahead forecast.
|
This is clearly just a matter of definition or convention, and of almost no practical importance. If $\alpha$ is set to its traditional value of 0.05, is a $p$ value of 0.0500000000000... considered to be statistically significant or not? Is the rule to define statistical significance usually considered to be $p < \alp... |
I use Andrew F. Hayes' macro for SPSS (HCREG at http://www.afhayes.com/spss-sas-and-mplus-macros-and-code.html) to perform multiple regression analyses with robust standard errors.
The information I get in the output is limited compared to the one SPSS provides when applying multiple regression. For example, there are ... |
These are the values:
18.2 17.6
------------------------------------------------------------------------------------------------------------
18.9 18.6
-------------------------------------------------------------------... |
I am running an experiment where I collect two data sets and I wish to measure the difference between the two. The two data sets are independent, with unknown probability distribution, and may not always have the same length.
Calculating the mean difference is easy as pie, but i also want a measure of the standard devi... |
There's a heuristic, which I find appealing, that says that for every stochastic algorithm, there should be at least one deterministic algorithm that performs better, provided the universe isn't adversarial. I first heard this principle articulated by Eliezer Yudkowsky here.
Markov Chain Monte Carlo algorithms, which a... |
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