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Let $S_n = \frac{1}{n}\sum_{i=1}^n X_i$, and $T_n = \frac{1}{n}\sum_{j=1}^nY_i$, where
The $X_i$ are iid, the $Y_i$ are iid (with a different law)
$X_i$, and $Y_i$ are dependent
For $i\neq j$, $X_i$ and $Y_j$ are independent.
Is there a central limit type result for $S_n^2 - T_n^2$?
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Is there a closed form solution for this inverse CDF?
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An average of n birds fly through an area, in an hour, following a Poisson process. (I think this means the hours don't matter; there's no influence in the number of birds that fly through, at different parts of the day, hypothetically. Correct me if I'm wrong.)
P1 is the probability that exactly m birds fly through be... |
I know roughly and informally what a confidence interval is. However, I can't seem to wrap my head around one rather important detail: According to Wikipedia:
A confidence interval does not predict that the true value of the parameter has a particular probability of being in the confidence interval given the data ac... |
I am hoping that I can ask this question the correct way. I have access to play-by-play data, so it's more of an issue with best approach and constructing the data properly.
What I am looking to do is to calculate the probability of winning an NHL game given the score and time remaining in regulation. I figure I coul... |
There are quite a few methods for parameter estimation out there. MLE, UMVUE, MoM, decision-theoretic, and others all seem like they have a fairly logical case for why they are useful for parameter estimation. Is any one method better than the others, or is it just a matter of how we define what the "best fitting" esti... |
I am studying a dynamical system that takes as an initial condition a list. I want to analyze the evolution of Shannon's entropy in this system. I know the maximum entropy (50) and the minimum (0). Pure random conditions have almost maximum entropy, and so it is hard to analyze changes in it unless it decreases. I set ... |
I want to compare sixteen Case Fatality Rates (deaths per 100 cases) of a particular disease from sixteen different populations across 7 years. Each population received the same treatment but some regions did not implement it properly. As a result, I am trying to show the effectiveness the treatment had in each of the ... |
as question, since we can do the conversion from odds ratio (p1/q1)/(p2/q2) to relative risk (p1/(p1+q1))/(p2/(p2+q2)) fairly easily, I wonder if there is anything that I need to pay attention before doing this?
It is obvious that if I am doing a case-control study, I shouldn't do a conversion, because I never know the... |
I have serial hematological measurements data and I have plotted their means and SE in Stata. On the y-axis I have for example hemoglobin and time (visit days) on the x-axis hence I can visualize hemoglobin levels with time (whether it is decreasing or in increasing). The level decreases up to sometime and increases ag... |
I calculated the quantiles for an Epanechnikov kernel which I'm using to estimate the density of a sample. What I need is to find the sample quantiles knowing that it is composed of many Epanechnikov kernels. Is there a way to calculate at wich data points the different quantiles are using the kernel inverse CDF formul... |
I want to calculate a better bandwidh for my kernel density estimator, which is an Epanechnikov. I use Silverman's formula which involves the standard deviation of the sample, the sample size and a constant, but I'm getting a very smooth curve in most cases and I would prefer if it were more balanced. Thank you for any... |
I need to convert the table A to table B. How can I do that using R?
TABLE A
Y 10
Y 12
Y 18
X 22
X 12
Z 11
Z 15
TABLE B
X 22 12
Y 10 12 18
Z 11 15
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Note: I've updated the example case code, there were some errors in the previous version
Cross posted to R-help, because I half suspect this is 'unexpected behaviour'.
I want to predict values from an existing lm (linear model, e.g.
lm.obj) result in R using a new set of predictor variables (e.g.
newdata). Specificall... |
Suppose I want to build a binary classifier. I have several thousand features and only a few 10s of samples. From domain knowledge, I have a good reason to believe that the class label can be accurately predicted using only a few features, but I have no idea which ones. I also want the final decision rule to be easy... |
If I see Rmath.h in /usr/share/R/include, the signature of the function dpois or Rf_dpois is
double dpois(double, double, int);
However, if I do ?dpois in R, I see:
dpois(x, lambda, log = FALSE)
Are these both the same thing? If yes, can someone please clarify?
Also I tried to find the code for dpois at R-svn.
Ca... |
Let's say you regress monthly stock returns, and the regression model has a standard error around such monthly stock returns of 2%. Next, you forecast the next year annual stock return based on the regressed monthly returns. What is the standard error around this annual stock return?
Some may think this is not a ver... |
Here's what I want to do, but there seem to be no predict method for the mlogit. Any ideas?
library(mlogit)
data("Fishing", package = "mlogit")
Fish <- mlogit.data(Fishing, varying = c(2:9), shape = "wide", choice = "mode")
Fish_fit<-Fish[-1,]
Fish_test<-Fish[1,]
m <- mlogit(mode ~price+ catch | income, data = Fish_f... |
I'm doing an autocorrelation analysis for a spatially distributed collection of observations. To perform my analysis, I am using Moran's I statistic.
My questions are: (1) What are the implications and benefits of using different weighting functions, i.e. $d^{-1}$, $d^{-2}$, $\exp(-d)$, and (2) Is there any (perhaps in... |
I am doing the following to fit my data using an exponential function:
# Define the data
data <- c(67, 81, 93, 65, 18, 44, 31, 103, 64, 19, 27, 57, 63, 25, 22, 150,
31, 58, 93, 6, 86, 43, 17, 9, 78, 23, 75, 28, 37, 23, 108, 14, 137,
69, 58, 81, 62, 25, 54, 57, 65, 72, 17, 22, 170, 95, 38, 33, 34, ... |
I've seen at least 3 sources on time series* state that the component of a series that is variously called random, stochastic, or noise (something clearly separate from any deterministic, patterned component) itself consists of 2 parts, a systematic part and an unsystematic part. I can't for the life of me figure out ... |
Please pardon me if this question is not clear. I am not sure if I am using the right terminologies.
I have conducted an experiment in different environments multiple times. So my data looks something like this:
Environment1 1.2 2.1 1.1 1.5 1.6
Environment2 4.2 2.6 3.5 2.5 2.9
Environment3 7.2 4.6 5.3 4.5... |
An exponential model is a model described by following equation:
$$\hat{y_{i}}=\beta_{0}\cdot e^{\beta_{1}x_{1i}+\ldots+\beta_{k}x_{ki}}$$
The most common approach used to estimate such model is linearization, which can be done easily by calculating logarithms of both sides. What are the other approaches? I'm especiall... |
Given the dataset cars.txt, we want to formulate a good regression model for the Midrange Price using the variables Horsepower, Length, Luggage, Uturn, Wheelbase, and Width. Both:
using all possible subsets selection, and
using an automatic selection technique.
For the first part, we do in R:
cars <- read.table(file=... |
I have to implement a genetic algorithm and therefore select the "fittest" of all possible members of a generation.
I have the following arrays of fitnesses, their weighed equivalents and a cumulative array.
Fitnesses: [0.2, 0.0, 0.2, 0.0, 0.0, 0.0]
Weighed Fitnesses: [0.5, 0.0, 0.5, 0.0, 0.0, 0.0]
Cumulative Fitnesses... |
I was trying to fit my data into various models and figured out that the fitdistr function from library MASS of R gives me Negative Binomial as the best-fit. Now from the wiki page, the definition is given as:
NegBin(r,p) distribution describes the probability of k failures and r
successes in k+r Bernoulli(p) trials... |
I have a design matrix of p regressors, n observations, and I am trying to compute the sample variance-covariance matrix of the parameters. I am trying to directly calculate it using svd.
I am using R, when I take svd of the design matrix, I get three components: a matrix $U$ which is $n \times p$, a matrix $D$ which ... |
Say I have a list with $n$ elements (say number $1$'s) and I want to do 1000 random changes to them, such as a $+1$. If I (1) picked a random element, (2) changed it, and then (3) did these two steps (1)+(2) another 999 times, this would probably be completely random, right?
Now, what if, whenever I change an element,... |
I have been reading the description of ridge regression in Applied Linear Statistical Models, 5th Ed chapter 11. The ridge regression is done on body fat data available here.
The textbook matches the output in SAS, where the back transformed coefficients are given in the fitted model as:
$$
Y=-7.3978+0.5553X_1+0.3681X... |
What properties do these measures have and how can I determine which one is better for a given purpose? What are extreme cases where they differ a lot?
|
I am reading the second edition of Categorical Data Analysis by Alan Agresti, and somehow stuck in the following second paragraph:
I don't quite understand why $\beta\pi(\hat{x})(1 - \pi(\hat{x}))$ will give the probability when $x = 26.3$, can anyone enlighten me? Thanks.
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I have no math or stats background, so this may be a real dumbo question.
I'm developing a time estimation app which would let user enter her worst case and best case estimates, and then select a probability curve which she feels looks realistic.
I needed to draw some kind of curve that sums up to 1, so I came up wi... |
I'm working with a two-state process with $x_t$ in $\{1, -1\}$ for $t = 1, 2, \ldots$
The autocorrelation function is indicative of a process with long-memory, i.e. it displays a power law decay with an exponent < 1. You can simulate a similar series in R with:
> library(fArma)
> x<-fgnSim(10000,H=0.8)
> x<-sign(x)
> a... |
I want to measure the correlation between two 1D point processes $x$ and $y$. Ordinarily I could use the bivariate K-function
$K(t) = \frac{T}{n_xn_y} \sum_{i=1}^{n_x} \sum_{j=1}^{n_y} w(x_i,y_j) I[d(x_i,y_j)<t]$
where $n_x$ is the number of observations in $x$ and $n_y$ is the number of observations in $y$. Deviation ... |
... instead of e.g. the popular Equal-Width-Histograms.
Additional question: What is a good/robust rule of the thumb to calculate the number of bins for equal frequency histograms (like the Freedmann-Diaconis-Rule for equal-width).
|
I am a beginner in statistics, and I want to learn machine learning :). Therefore, I have gathered some sample data to practice. But, the problem is I want to create a feature (or attribute), which is common for every entity. But, this feature is observed and measured for entity X in Y meters and Z seconds, and for ent... |
The data files from http://www.csie.ntu.edu.tw/~cjlin/libsvm/ are in 'svm' format. I am trying to read this in to sparse matrix representation in R. Is there an easy/efficient way to do this?
Here is what I am doing now: read in file line by line (800,000 lines), for each line separate classes, values, and cols. Sto... |
I've fit a model with several independent variables, one of which is the lag of the dependent variable, using the dynlm package.
Assuming I have 1-step-ahead forecasts for my independent variables, how do I get 1-step-ahead forecasts for my dependent variables?
Here is an example:
library(dynlm)
y<-arima.sim(model=lis... |
How can I remove duplicate rows from this example data frame?
A 1
A 1
A 2
B 4
B 1
B 1
C 2
C 2
I would like to remove the duplicates based on both the columns:
A 1
A 2
B 4
B 1
C 2
Order is not important.
|
We have n actors. Each actor chooses from n*2 actions. How can I calculate the probability that at least one actor will choose a unique outcome?
For example, say we have 5 pickup artists in a town with 10 bars. Each PUA chooses a bar at random. What are the odds that at least one PUA will have a bar to himself/herself?... |
I have 80 chemical batches, each of which has 8 associated measurements like pH, viscosity, etc. Is there a way to use Principal Components Analysis or Factor Analysis to group the similar batches together? I know I can use cluster analysis, but I want to have a different visual representation of batch groups other t... |
I'm writing a program for an assignment for my Probability and Statistics course. This program performs several millions of simulated coin tosses, and then analyses various properties of the generated sequence.
One of the things it does is count how many runs does the generated sequence contain, and their lengths. One... |
Not sure if you can help me but here's the problem.
I have two binomial proportions A and B (95% CI) -
$A = 2\% \pm 0.2\%,\quad B = 3\% \pm 0.2\%.$
In other words, B's proportion is 50% higher than A's.
Business people tend to prefer speaking about this difference in terms of a percentage increase. In other words, B's ... |
I have a logistic regression model in GeoBugs to estimate predictors of prevalence of a disease. Can anyone tell me if there is a simple way to determine the lower and upper bounds of phi for spatial.exp.
This is part of the model:
Infected[i] ~ dbin(p[i], tested[i])
logit(p[i]) <- alpha + beta1*covar1[i] + beta2*covar... |
I would appreciate some help getting some EM stuff straight. So, say I generate data in R as follows:
N <- 100
epsilon <- rnorm(N)
X <- 10*runif(N)
beta.0 <- 10
beta.1 <- 3
sigma <- 2
Y <- beta.0 + beta.1 * X + sigma * epsilon
epsilon2 <- rnorm(N)
X2 <- 10*runif(N)
Y2 <- 3 - X2 + 0.25 * epsilo... |
I would like to apply Bayesian network on some data. However, some of the variables are related to time.
E.g. Number of time he/she visit library.
As the value can be defined as Total number of this person visits, Average weekly number of he/she visit, Daily number of visits, or even Number of visits in the last 3 da... |
Apologies in advance - I'm a bit of a newbie with R but I've been Google-ing this for weeks and I haven't found a straight answer.
The problem
Basically, I'm looking to plot proportions with their confidence intervals on a box and whiskers plot using the R environment.
i.e. Plot the results of binom.test(100,1000) and ... |
I have several query frequencies, and I need to estimate the coefficient of Zipf's law. These are the top frequencies:
26486
12053
5052
3033
2536
2391
1444
1220
1152
1039
|
I've identified a Single Nucleotide Polymorphism (SNP) that is associated with a variable of interest (lets just call it height) using a Genome Wide Association Study (GWAS). The SNP can be of the values A/A, A/G or G/G in each of the 69 samples.
I also have gene expression data for the 69 samples and it appears that t... |
Let Year 1 be last year's data and Year 2 be this year's data.
Suppose that in Year 1, you had a likert scale that was 1-9 (Categorical/Ordinal) and that in Year 2, for the same question you had a likert scale that was 1-5 (Categorical/Ordinal).
What would be some of the things that you would try (if at all) to compa... |
A few days ago I saw a post on how to setup a SweaveR, which would allow for a user to directly export things like tables, graphs, etc. into Latex. I couldn't quite follow the directions.
Can anyone give step-by-step instructions on how to do it on both, Mac and Windows?
|
I'm trying to solve a problem for least angle regression (LAR). This is a problem 3.23 on page 97 of Hastie et al., Elements of Statistical Learning, 2nd. ed. (5th printing).
Consider a regression problem with all variables and response having mean zero and standard deviation one. Suppose also that each variable has i... |
I have several time series (generated from a numerical model) that go through an initial stage of spinup, followed by a period of dynamic equilibrium, that presumably exists for all times beyond the spinup period. See this link for an example.
While I can usually estimate the spinup time and the equilibrium by inspecti... |
I want to compare few methods of variable selection. I want to do it using simulations. I'm aware of the fact that it won't be an ultimate answer to question 'Which method is the best one?', but I'm looking just form some hint. To do such simulations I need a method to draw a 'random linear model'. Is there any well ac... |
I have a dataframe df as shown below
name position
1 HLA 1:1-15
2 HLA 1:2-16
3 HLA 1:3-17
I would like to split the position column into two more columns based on the ":" character such that i get
name seq position
1 HLA 1 1-15
2 HLA 1... |
I have recently graduated with my masters degree on medical and biological modeling, accompanied with engineering mathematics as a background. Even though my education program included a significant amount of courses on mathematical statistics (see below for a list), which I managed with pretty high grades, I frequent... |
I'm considering building MATLAB and R interfaces to Ross Quinlan's C5.0 (for those not familiar with it, C5.0 is a decision tree algorithm and software package; an extension of C4.5), and I am trying to get a sense of the components I would need to write.
The only documentation I found for C5.0 is here, which is a tuto... |
I have a question about the Kullback-Leibler divergence.
Can someone explain why the "distance" between the blue density and the "red" density is smaller than the distance between the "green" curve and the "red" one?
|
My intuition says that the third equation must be "the length of the gradient squared less than epsilon".
$x_{k+1} = x_k - f(x_k)$
$x_{k+1} = x_k + 1$
$|f(x_k)|^2 < \epsilon$
However, I am not sure whether it is the standard form.
How would you write the standard form of the gradient method, and particularly its endi... |
Let's say that there is a table like the one below, where for each mutant (A, B, C, etc.) protein or peptide we have a binding and a functional information (true/false) column, and for each amino acid in that protein, we have some kind of amino acid property like hydrophobicity:
Protein Binding Functional 1 2 3 ... |
Can an effect size be calculated for an interaction effect in general and more specifically using the F-statistic and its associated degrees of freedom? If yes, should this be done and what is the appropriate interpretation of the effect size given the nature of interaction effects? Initially, I assumed the answer is... |
Given a table comprising three columns,
1 2 0.05
1 3 0.04
2 3 0.001
and a matrix with defined dimensions,
mat <- matrix(NA, nrow = 3, ncol = 3)
[,1] [,2] [,3]
[1,] NA NA NA
[2,] NA NA NA
[3,] NA NA NA
Is there an efficient way to populate the matrix with the entries in the third column of the t... |
I'm building a database of economic and political indicators provided by the World Bank and other similar sources. I would like to run uni- and multivariate analysis of these indicators over the past 20 years of data. I'll be using JMP to analyze the data.
Here's an excerpt of the database structure:
ID | Pop... |
What are the major machine learning theories that maybe used by Twitter for suggesting followers?
|
What are the best quantitative models for trend detection?
I.e. market trend.
|
The data: I have worked recently on analysing the stochastic properties of a spatio-temporal field of wind power production forecast errors. Formally, it can be said to be a process $$ \left (\epsilon^p_{t+h|t} \right )_{t=1\dots,T;\; h=1,\dots,H,\;p=p_1,\dots,p_n}$$
indexed twice in time (with $t$ and $h$) and once i... |
I would like to be sure I am able to compute the KL divergence based on a sample.
Assume the data come from a Gamma distribution with shape=1/.85 and scale=.85.
set.seed(937)
theta <- .85
x <- rgamma(1000, shape=1/theta, scale=theta)
Based on that sample, I would like to compute the KL-divergence from the real underl... |
I have fitted a dynamic panel data model with Arellano-Bond estimator in gretl, here is the output:
Model 5: 2-step dynamic panel, using 2332 observations
Included 106 cross-sectional units
H-matrix as per Ox/DPD
Dependent variable: trvr
coefficient std. error z p-value
-------------------... |
Can the KS3D2 test as suggested by Fasano and Franceschini (1987) be used when one of the three variables take discrete values between 0-40? The other two variables are continuous.
|
I have a folder with a hundred comma separated files (CSVs) of which the filename equals a company stock exchange followed by it's symbol, delimited with a "_", eg: NASDAQ_MSFT.csv
Each file contains historical daily stock information, eg. a csv file looks like:
Date,Open,High,Low,Close,Volume
29-Dec-00,21.97,22.91,21.... |
Given $X_1$ and $X_2$ normal random variables with correlation coefficient $\rho$, how do I find the correlation between following lognormal random variables $Y_1$ and $Y_2$?
$Y_1 = a_1 \exp(\mu_1 T + \sqrt{T}X_1)$
$Y_2 = a_2 \exp(\mu_2 T + \sqrt{T}X_2)$
Now, if $X_1 = \sigma_1 Z_1$ and $X_2 = \sigma_1 Z_2$, where $Z_1... |
I used cforest and randomForest for a 300 rows and 9 columns dataset and received good (almost overfitted - error equal to zero) results for randomForest and big prediction errors for cforest classifiers. What is the main difference between these two procedures?
I admit that for cforest I used any possible input parame... |
Since regression modeling is often more "art" than science, I often find myself testing many iterations of a regression structure. What are some efficient ways to summarize the information from these multiple model runs in an attempt to find the "best" model? One approach I've used is to put all the models into a list ... |
I am doing some histogram rowstacked plots using the gnuplot command
plot 'file.dat' using (100.*$2/$6) title column(2), for [i=3:5] '' using (100.*column(i)/column(6)) title column(i)
I want to change all the colors used for fill the bars in the histogram. For change the first box color, I simply add lt rgb "color" b... |
How can I test effects in a Split-Plot ANOVA using suitable model comparisons for use with the X and M arguments of anova.mlm() in R? I'm familiar with ?anova.mlm and Dalgaard (2007)[1]. Unfortunately it only brushes Split-Plot Designs. Doing this in a fully randomized design with two within-subjects factors:
N <- 20 ... |
Hey everyone, thanks for taking the time to look at this question. This is pretty simple, and I understand statistics quite well, but I think I'm not wrapping my head around the words, it seems to me as if there's something missing. Here's the question.
The manager of the aerospace division
of General Aeronautics ha... |
I have a question on how to fit a censoring problem in JAGS.
I observe a bivariate mixture normal where the X values have measurement error. I would like to model the true underlying 'means' of the observed censored values.
\begin{align*}
\lceil x_{true}+\epsilon \rceil = x_{observed} \
\epsilon \sim N(0,sd=.5)
\end... |
There are well-known on-line formulas for computing exponentially weighted moving averages and standard deviations of a process $(x_n)_{n=0,1,2,\dots}$. For the mean,
$\mu_n = (1-\alpha) \mu_{n-1} + \alpha x_n$
and for the variance
$\sigma_n^2 = (1-\alpha) \sigma_{n-1}^2 + \alpha(x_n - \mu_{n-1})(x_n - \mu_n)$
from whi... |
I've recently been looking for top-of-the-line statisticians in a recruiting process for our company. Myself, I'm a Physics Engineering major. I gather that great mathematical statisticians have studied a bit different courses, and much more in depth.
When evaluating a candidate, are courses a good indicators of this ... |
There are a few things that are heavily used in the practice of statistics, data analysis, etc. and that form the common canon of education, yet everybody knows they are not exactly true, useful, well-behaved, or empirically supported.
So here is the question: Which is the single worst idea still actively propagated?
P... |
Along the same lines as this question, is there a nice way to display regression results in MATLAB from a single or many regressions in table or graph form?
|
Suppose I have a neural network, with input variables $a, b, c, d, f, g$ and output variables$ m, n, o, p, q$.
Given different input values, the neural network will output corresponding $m, n, o, p, q$.
Now I want find out the best input values which can maxmize $m, n$, while minimize $o,p,q$ with different weights as ... |
I have dendrogram and a distance matrix. I wish to compute a heatmap -- without re-doing the distance matrix and clustering.
Is there a function in R that permits this?
|
I have a series of measurements in which something is sampled and placed into either category 1 or category 2. I have 3x2x3 factors for each set of measurements, and each set of measurements is done independently 3 times.
What is a good statistical test to look examine the combined effects of each factor, both indep... |
Context
I have two sets of data that I want to compare. Each data element in both sets is a vector containing 22 angles (all between $-\pi$ and $\pi$). The angles relate to a given human pose configuration, so a pose is defined by 22 joint angles.
What I am ultimately trying to do is determine the "closeness" of the tw... |
Here is my example. Supose we evaluate a characteristic using two different methods (a and b) and we want to study if both methods performs in a same way. We also know that these two measures have been recorded from two different groups, and the mean values for each one of these groups are highly different. Our data se... |
Kavosh is a recent package designed for network motif discovery. To give a comparison, Kavosh generates a collection of similar networks using an MCMC process.
The networks in consideration are directed graphs without loops or multiple edges. Similar networks have the same vertex set and the same in-degrees and out-d... |
Look at this picture:
If we draw a sample from the red density then some values are expected to be less than 0.25 whereas it is impossible to generate such a sample from the blue distribution. As a consequence, the Kullback-Leibler distance from the red density to the blue density is infinity. However, the two curves ... |
I came by the post "Post-hoc Pairwise Comparisons of Two-way ANOVA" (responding to this post), which shows the following:
dataTwoWayComparisons <- read.csv("http://www.dailyi.org/blogFiles/RTutorialSeries/dataset_ANOVA_TwoWayComparisons.csv")
model1 <- aov(StressReduction~Treatment+Age, data =dataTwoWayComparisons)
su... |
I recently read the advice that you should generally use median not mean to eliminate outliers.
Example:
The following article
http://www.amazon.com/Forensic-Science-Introduction-Scientific-Investigative/product-reviews/1420064932/
has 16 reviews at the moment:
review = c(5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 4, 4, 3, 2, 1, 1)... |
I'm teaching an intro stats class and was reviewing the types of sampling, including systematic sampling where you sample every kth individual or object.
A student asked if sampling every person with a particular characteristic would accomplish the same thing.
For example, would sampling every person with a blue t-sh... |
I'm analysing some data where I would like to perform ordinary linear regression, however this is not possible as I am dealing with an on-line setting with a continuous stream of input data (which will quickly get too large for memory) and need to update parameter estimates while this is being consumed. i.e. I cannot j... |
I'm doing a simulation study which requires bootstrapping estimates obtained from a generalized linear mixed model (actually, the product of two estimates for fixed effects, one from a GLMM and one from an LMM). To do the study well would require about 1000 simulations with 1000 or 1500 bootstrap replications each time... |
Suppose I have the following simplified distribution:
time | value
1 | 2
2 | 4
3 | 8
4 | 16
1 | 1
2 | 3
3 | 9
4 | 27
1 | 40
2 | 20
3 | 10
4 | 5
1 | 12
2 | 1
3 | 99
4 | 23423
These are all part of the same dataset (so one x can have multiple values here, eg. time = 1 c... |
I hope this isn't a silly question. Let's say I have some arbitrary continuous distribution. I also have a statistic, and I'd like to use this arbitrary distribution to get a p-value for this statistic.
I realize that in R it's easy to do this as long as your distribution fits one of the built-in ones, like if it's no... |
I am unable to get the zscore function to work. When I try to call it, I get the following error:
could not find function zscore
The online documentation online states that it is in basic R library.
Searching online reveals that other people had the same problem some time ago - though on macs. Does anyone know how to... |
In a lottery, 1/10 of the 50 000 000 tickets give a prize.
What is the minimum amount of tickets one should buy to have at least a 50% chance to win?
Would be very glad if you could explain your methodology when resolving this. Please consider this as homework if you will.
|
During an article revision the authors found, in average, 1.6 errors by page. Assuming the errors happen randomly following a Poisson process, what is the probability of finding 5 errors in 3 consecutive pages?
Please explain your methodology, as the main purpose of the question is not getting the answer but the "how t... |
I am looking for a book/case study etc on how to build a fraud detection model at the transaction level. Something applied rather than theoretical would be really helpful.
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I have a large amount of variables (24) to predict a Y/N value, and I would like help for writting a procedure that automatically tries the different results of the factor selection to see how good the regression turns out to be, and of course I want to save the best model for later use.
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