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I have located references that indicate that a 1-sided confidence band is equivalent to the 95% 2-sided confidence band on a linear regression. Does this equivalence hold true for prediction intervals over a linear regression model?
Example:
Given a set of data with a random sampling of age vs strength values, and usi... |
This may be an elementary question which is why I have not been able to find it on Stackexchange or Mathoverflow however I am having problems with the arithmetic involved in updating likelihoods using Bayes theorem for a problem I am working on.
Background:
I am attempting to give likelihood forecasts to future events... |
What is the semantic difference between Mean Squared Error (MSE) and Mean Squared Prediction Error (MSPE)?
|
I have some random numbers which are generated from Gaussian Distribution. But I don't know the mean, standard deviation of that distribution. How can I find them using random numbers?
|
I’m trying to estimate the out-of sample forecast of an ARIMA model, I tried the code below, but it totally doesn’t work!
for(i in 1:83) {
mod[i] <- arima(window(betahat[,1], start=1, end=109+i),order=c(1,0,0),include.mean=TRUE)
pre[i] <- predict(mod[i],12)
error[i] <- pre[i]$pred[12]-betahat[(109+i+12),1]
}
... |
The Breslow estimate is commonly used in the Cox proportional hazards model. However this paper by Deborah Burr
Burr, D. (1994). On Inconsistency of Breslow's Estimator as an
Estimator of the Hazard Rate in the Cox Model. Biometrics,
50(4), 1142-1145.
claims that the estimator is inconsistent (I do not have this pape... |
SPSS Modeler seems like a great tool for data mining (especially for prediction etc.) but it is extremely costly for individuals like me (around 20,000 euros excl. tax). There is also a video.
I am wondering if software as expensive as this really adds value. If it does, my university may consider purchasing it.
What s... |
I am trying to cluster the companies listed in a stock market on the basis of the risk and returns.
I have about 100 companies (categories) and two variables (risk, return) under each category. The data comprises of daily data for the past 10 years.
I want to run a cluster analysis to group the companies (categories) b... |
I am fighting to understand a perhaps simple question, described below.
Let $X$ be a positive continuous random variable. Now, define another random variable
$$
Y = \begin{cases}
\text{undefined} & \text{ if } X \leq d \\
X - d & \text{ if } X > d
\end{cases} \> .
$$
Now my job is to calculate the pdf of $Y$.
My ... |
I'm doing some experiments with neural networks and I wanted to ask for some support to verify my methodology and my results.
My setup: I have separated my data into time slots of 5 seconds, i.e. all timestamps are within 5 seconds. For each slot I get approx. 1000 samples. Furthermore, I have 7 features for each sampl... |
I would like to have some advice on the way to calculate burstiness. I am working with a set of text data, where every term is calculated with their frequency in newspaper for 2 weeks, e.g. "apple" during their iphone4s release will be day1 = 10, day2 = 300, day3 = 25, and so on till day14. So if popular term such as O... |
I am working with Rice's Mathematical Statistics and Data Analysis and on page 179 it introduces Monte Carlo integration. This question is a smallish revision based on comments from @Iterator (in R chatroom on stackoverflow.com).
What I'm trying to show the law of large numbers
$I(f) = E[f(X)]$
where $I(f) = \frac{1}{\... |
I have to forecast a time series in R of a Internet network traffic bitrate.
The data are in file http://www.forumaltavilla.it/joomla/datitesi/dati.dat and the sampling time is every 0.05 seconds.
Now, i want to use HoltWinters forecasting. My problem is setting the parameter deltat. On the Internet i saw deltat is the... |
I have an issue I cannot solve myself and hope I can get some pointers here:
I have a RCB design with 10 tree species each replicated 5 times in 5 blocks. I classified all species according to their height and assigned them to 3 groups (A, B and C). Then, I chose 2 species from each group and take my measurements on 8 ... |
Proportion, ratio, and percentage data is very common in ecology (eg, % of flowers pollinated, male:female sex ratio, % mortality in response to a treatment, % of leaf eaten by an herbivore). An article was recently published by some applied statisticians in the journal Ecology titled "The arcsine is asinine: the anal... |
Using the Stata graph twoway command, I have created a scatterplot with a quadratic best fit line, using the qfit command. How can I get the equation of the best fit line?
Example:
graph tw (scatter y x) (qfit y x)
|
I have the survival dataset of a population with a special disease. I´d like to compare this population with the general population to see whether this population has a decreased life-expectancy overall. What I had in mind was to create a control for each patient in the dataset and enter the age, sex and cohort specifi... |
As a programmer, I am used to a vibrant documentation system with exhaustive references and tutorials online. Does such a system exist for Stata? Where do people go for quick stata questions (besides Cross Validated)? How did people here learn Stata?
|
Why is it that the HoltWinters function in R gives vastly different parameter estimates, say of alpha and beta, when gamma is set as 0 versus set as False? It would seem from the structure of the model the 2 should be specifying equivalent models?
|
For high dimensional data, LASSO is useful as it allows to determine the few significant covariates. I think compressed sensing is an upgrade of LASSO. According to the wiki page:
[the LASSO estimator] recovered sparse solutions, but the required type and number of measurements were sub-optimal and subsequently great... |
I'm working on an alignment algorithm using LAMP HMM library.
This library supports Gaussian probability distribution but it does not seem to support Gaussian Mixture Model.
What I want is, to input continuous observations into multivariate Gaussians for training and alignment purposes.
It may be easy if I extend the c... |
I have been asked by a journal editor to combine two separate measures of child disruptive behaviour into one variable. One meaure is parent rated and is from the 36-item Eyberg Child Behaviour Checklist. It is measured on a 7-point likert scale and gives a total score. The other measure is teacher-rated and is from th... |
I want to find out the relationship between 6 independent variable (4 categorical, 2 continuous) and 6 dependent variables (5 likert scale).
As my data is categorical (likert scale) I thought of using logistic regression (i think ordinal), but I have to reduce my dependent variables for which I used principal component... |
I have several questions regarding the usual gaussianity (broad normality) assumptions in econometrics. Though people often check for normality (with apparently weak tests), I've seen just one example of "gaussianity" testing.
1.Is the "finite variance" assumption the same as a gaussianity assumption? Ie., is it the s... |
I have a data set with a few discrete variables having a lot of classes(>100,000). This is too large to encode using a one-hot method. What is the best way to deal with such variables? Should I be using some other model?
I have yes/no responses to a set of questions and am trying to predict features based on these. But... |
Thank you so much for your input to my question. My variable is HPtsLag and is continuous (although integers, and <=18 - perhaps this could be the issue?). Anyway, here is my code and output. Hopefully this explains it better.
> mylog = glm(cbind(HW,NotHW) ~ HPtsLag, data = g, family = binomial)
> summary (mylog)
Cal... |
I have built what I think is a very good predictive model using randomforest. The initial dataset was imbalanced for the outcome 2:1, so I randomly resampled the dataset to balance it, then trimmed the predictors down to 20 or so and managed to get the sensitivity and specificity of the model up to the 90s based on 10-... |
Empirically the quartimax-/varimax-rotation has proven useful and it was always converging in my applications. But from my readings years ago (most prominent S.Mulaik and K.Überla monographies on factor nanalysis) I have a vague remembering, that the fact of a proof of convergence has been mentioned but I've never see... |
I have two questions about the notion of block in experimental design :
(1) What is the difference between a block and a factor ?
(2) I tried to read some books but something is not clear: it seems that the authors always assume that there is no interaction between the "block factor' and other factors. Is it right, and... |
I'm displaying time-series data as a "stacked line" or "stacked area" chart. (E.g. with percentage data, data points at 10%, 20% and 30% are displayed at 10%, 30% and 60% on the chart.) Unsmoothed lines through the data points obviously never cross (and never go below the minimum data value or above the maximum total; ... |
I am a computer scientist with little statistics background and I am trying to find the best fitting distribution for some data set (using MATLAB). To assess the goodness of fit I use both Kolmogorov Smirnov (KS) and Anderson Darling (AD) tests, and here are the p-values for the same data set:
Distribution AD ... |
I am running a generalized linear model in SPSS on data highly skewed to the right with a bunch of zeroes (average # caterpillars per tree species branch sampled) so I decided to use the Tweedie distribution.
In the model I ran both untransformed data (with link=log) as well as $\log(x+1)$ transformed data (with link=... |
I have timeseries like this:
as you can see there are changes regarding the amplitude. Is there a test to check this kind of changes?
Important annotations:
I do not know if the series have changes in amplitude
If there is a change in amplitude I do not know the point of the change
The changes can be more then ONE (... |
I am using a generalized linear model in SPSS to look at the differences in average number of caterpillars (non-normal, using Tweedie distribution) on 16 different species of plants.
I want to run multiple comparisons but I'm not sure if I should use a Sidak or Bonferroni correction test. What is the difference betwee... |
I have count data (demand/offer analysis with counting number of customers, depending on - possibly - many factors). I tried a linear regression with normal errors, but my QQ-plot is not really good. I tried a log transformation of the answer: once again, bad QQ-plot.
So now, I'm trying a regression with Poisson Errors... |
I have a data set with about 15,000 labeled observations of a single continuous value.
What is the best way to plot this type of data? I'm playing around with various histograms and density plots, but I can't seem to figure out the best way to plot this data set. Any suggestions?
My data looks like this:
label ... |
Let's say that I generate the probability of an outcome based on a certain factor and plot the curve of that outcome. Is there any way to extract the equation for that curve from R?
> mod = glm(winner~our_bid, data=mydat, family=binomial(link="logit"))
> summary(mod)
Call:
glm(formula = winner ~ our_bid, family = bino... |
I would like to implement an algorithm for automatic model selection.
I am thinking of doing stepwise regression but anything will do (it has to be based on linear regressions though).
My problem is that I am unable to find a methodology, or an open source implementation (I am woking in java). The methodology I have ... |
Suppose you have some complex model you want to sample from by Markov chain Monte Carlo. There are many types of situations where you can divide your variables into, say, two groups, and efficiently and exactly sample the variables in one group conditional on the others. That is, we can sample from
$ p(x | y)$
and
$ ... |
I have a list of tokens/words which co-occur with each other. Some of these tokens co-occur more than the others. Moreover, there's a conditional relationship between many. For example, "bat" occurs conditionally with "sport" & "baseball". Such conditional relationships can be on multiple variables. I want to represent... |
I have a situation where an event is supposed to occur every x minutes for a number of different sites (each site could be configured for a different time interval x). From time to time the event may fail.
I'd like to be able to predict an interval of time that I should worry if an event hasn't occurred. (e.g. for site... |
I have observed the following pattern of behavior in my data-set and I'm wondering how I can explore whether I can predict Y using a value of X. This plot is a 2D histogram of values.
I have previously explored interquartile regression to identify the upper bound, but I'm wondering if there are any other approaches wh... |
Let's say that I'm trying to find the factors which help predict whether I wear red shoes or not during a year long time-period. I could look at weather, day of the week, month, and other factors. However, how much variation does there need to be in the dependent variable for me to be certain that I am acctually measur... |
I have read from here and understand how to calculate the estimated logit from a fitted logistic regression model, but how to work on the confidence interval? As it involved a variance-covariance matrix and I think it is better to have a program to do the calculation, rather then doing it by myself.
Thanks.
Edit 01
I h... |
Given a collection of $(x,y)$ data, one might do a non/semiparametric regression of $y$ on $x$ to understand how to predict the $E(Y|X)$. Similarly, if one has enough data, it might be useful take a narrow vertical slice of the data (a small range of $x$), and try to understand the pdf of $Y$ at that point. However, ... |
I am reading Hosmer's Applied Logistic Regression, and I am a bit stuck in chapter 3, when taking about interaction and confounders.
In page 77, it states the following:
Using the estimated coefficient for LWD in model 1 we estimate the odds ratio as $\exp(1.054)=2.87$. The results shown in Table 3.14 indicate that AG... |
Possible Duplicate:
Including the interaction but not the main effects in a model
I'm studying logistic regression now. And I have a question:
Suppose I have a logistic regression model as below:
$$y=\beta_0+\beta_1x_1+\beta_2x_2+\beta_3(x_1 x_2)$$
$\beta_0$ is the "constant" coeffficient (I wonder if that is a corr... |
I've worked with the mutual information for some time. But I found a very recent measure in the "correlation world" that can also be used to measure distribution independence, the so called "distance correlation" ( also termed Brownian correlation): http://en.wikipedia.org/wiki/Brownian_covariance. I checked the papers... |
I am learning logistic regression modeling from the book Applied Logistic Regression by Hosmer.
I need to create a plot named "create univariable smoothed scatterplot on logit scale", something like this one (Figure 4.2 page 107):
Can anyone help? Thanks.
edit 01
Thanks for all the answers. I tried creating the plot, ... |
I am currently playing around with Gaussian process regression. I discovered some confusing facts that I would like to be answered:
When I optimize the parameters like the length and error terms for the covariance function I get different results for scaled targets like $y \times 100$. This leads to the next thing:
Wh... |
I'm not sure what words I should look for. I have an under determined dataset of 8000 correlated variables (sales) over 12 months (ie 12 observations for each variable). And I basically want to predict the future. Where should I start? PCA?
My question is, what are the techniques used to deal with lots of (correlated) ... |
It is well-known that an AR(p) process
$$
x_t=\sum_{i=1}^p \varrho_i x_{t-i} + \epsilon_t \,,
$$
is causal and stationary if and only if the roots of the polynomial
$$
\mathcal{P}(u) = 1 - \sum_{i=1}^p \varrho_i u^i
$$
are all outside the unit circle in the complex plane. (Here is a Cross Validated discussion on the t... |
I am trying to do a very simple regression analysis using a truncated normal distribution with WinBUGS.
Let's suppose the following model $Y|\beta_0,\beta_1,\sigma \sim Normal(\beta_0+\beta_1X,\sigma)$ where $Y$ is the grade of 13 students (from 0 to 10) and $X$ is the gender of each student (1 for Males and 0 for Fem... |
I have a set of numbers $S$, and for each $s_i\in S$, $0\lt s_i \lt 1$. I would like to transform them so that they sum up to $1$.
An obvious way to do it is to calculate $t_i=\frac{s_i}{\sum_i{s_i}}$, so that $\sum_i{t_i}=1$. I wonder if there is any other way to achieve the same effect, and what are the differences b... |
I asked the same question on math.stackexchange and had some responses, but I would also like to hear some input specifically from statisticians and data analysts and I feel that you guys may have something to offer.
The question is about finding reasonable ways of dividing a prize among $n$ people in the following sit... |
I have problems using the package segmented.
My linear regression is very simple, between offer and demand:
linearModel <- lm(demand~offer)
And so should be my model using "segmented":
piecewiseModel <- segmented(lm(demand~offer), seg.Z = ~ offer, psi = NA)
But I have an error message and I really cannot find a rea... |
Working with the generalized covariance formula for a vector $x$, I have the following:
$$E[(x-\mu)(x-\mu)^T)] = E(xx^T) - \mu E(x^T)$$
But the term $E(x^T)$ doesn't make much sense to me. Does anyone have an idea why I'm getting this term with my matrix algebra?
|
Consider the two-way ANOVA model with mixed effects :
$$
Y_{i,j,k} = \underset{M_{i,j}}{\underbrace{\mu + \alpha_i + B_j + C_{i,j}}} + \epsilon_{i,j,k},
$$
with $\textbf{(1)}$ : $\sum \alpha_i = 0$, the random terms
$B_j$, $C_{i,j}$ and $\epsilon_{i,j,k}$ are independent,
$B_j \sim_{\text{iid}} {\cal N}(0, \s... |
Suppose that one runs 8 correlation analyses but in two separate batches: Would the alpha-correction apply to all 8 tests as a family or each of the 4 tests as a family?
For example, if there are two research questions and both require correlation analysis, the researcher conducts the first 4 tests (for research questi... |
Is there a standard method of dealing with independent variables, where they are samples from a known distribution, and the sample sizes differ from sample to sample?
I'll give an example of what I mean. Suppose your sample consists in $n$ individuals, who have been given 3 different types of test. Let $Z_{i,j}$ be nu... |
I'm trying to solve an optimisation problem with stochastic gradient descent with the following properties:
It has a very large (1,000,000+ element) parameter vector.
Empirically, there seems to be a single maximum (though I can't prove this) so hill climbing is fine, however the problem is definitely not convex
I ca... |
I need to have software for detecting dependencies among data attributes. The simplest example: we have a database table representing results of some social quiz. Columns represent questions; rows, people who passed the quiz. We are searching for different interesting dependencies in the data.
Examples:
60% of men a... |
With a linear regression defined in BUGS, how should one implement model identification constraints such as having the mean of a group of parameters be zero, or having the group of parameters sum to zero?
EDIT: To clarify, I'm thinking of a model with, say, varying slopes, e.g.,
for (i in 1:N) {
y[i] ~ dnorm(mu[i], t... |
I am using the principle of maximum entropy to fit a density to a given set of samples. I want to generate new set of samples from the approximated density. Is there any way to draw samples from a density obtained by maximum entropy approach?
|
I have a Gaussian process regression implementation and developed some example data to test the capabilities of those methods. In the posterior calculation one gets the covariance matrix $K$. For some sample data this matrix has a 0 determinant and thus it is not invertible. Can someone see a problem in the covariance ... |
Is Koller's "Probabilistic Graphical Models" suitable as a textbook? Or is there another book which is more recommendable as textbook for a master-course?
Disclaimer: cross-posted from quora.com, where I got no answer.
|
Suppose you perform a parameter selection study in an environment with not-so-many data points. You divide the available data into training and testing set and you plan to validate the future model on a separate, validation set.
You do all your heuristics on the training set and when you are happy with the selected par... |
I am questionning the Chi-squared table given in 100 Statistical Tests (3rd Edition, 2006) by Gopal K. Kanji, reproduced in part below.
Specifically, I think the Two-sided and One-sided levels of significance on the right should be 0.02 and 0.01, instead of 0.01 and 0.005 (regaining consistency with the values below, ... |
I want to make forecast on my data by running an arimax model.
The data is like:
Value1, Flag1, Flag2, ................., FlagN
Value2, Flag1, Flag2, ................., FlagN
Value3, Flag1, Flag2, ................., FlagN
Value4, Flag1, Flag2, ................., FlagN
Value5, Flag1, Flag2, ................ |
I have a stationary time series and I want to calculate the autocorrelation coefficient of order 1. For that I use OLS. I know the autocorrelation parameters change over the time. Thus it is not trivial to fix a window length for the regression. Moreover I can easily do over-fitting by finding the windows which optimiz... |
I have a sample of data sets A = {a1, a2, a3, ...aN}
We will change each data value following the same pattern, say a1’ =a1*10, a2’ = a2*10.
Which statistics evaluated from this data set will be changed?
Assume that I increase the size of this data set simply by make copies for each data,
A’ = {a1, a1, a1, a2, a2, a2, ... |
I'm performing a weighted linear least squares fit, where the weights correspond to the number of counts of a specific observation. Due to the nature of the data, it is possible that a small handful of observations get weighted much more than the rest, so that the regression is dominated by, say, two data points only, ... |
I have a regression with a harmonic effect of day of the year, which interacts with other variables. I am not sure how to interpret the coefficients. My model is:
m1 <- lme(lcount ~ AirT + sin(2*pi/360*DOY) + cos(2*pi/360*DOY) +
AirT*sin(2*pi/360*DOY) + AirT*cos(2*pi/360*DOY) + RainAmt + RainAmt*AirT,
... |
I'm want to do a PhD in NLP and I'm defining the topic at the moment.
I've heard that NLP can be used to track online sentiment which in turn can be used for algorithmic trading on stock markets. See this hedge fund
I was wondering if NLP techniques, maybe with online sentiment tracking, could be used to predict sport ... |
I want to build a document classifier in R, using the Naive Bayes approach.
Here are steps, that I've done so far:
I have corpus with about 30 documents from 2 authors (Classes are: "target author" and "other author").
"Vocabulary" (training set) has been pre-processed (removed numbers, removed punctuation, words to l... |
If I give you three numbers that are independently and identically drawn from a standard normal distribution, then have I given you three samples or one sample?
If the answer is one sample, then is there a short name for what I have given you three of?
|
If I have a coin that is not necessarily expected to turn up heads half of the time, then is it correct to call the coin biased? Or does bias in statistics only mean the bias of an estimator in which case it would be inappropriate to describe the coin itself as biased?
This question does not mean to be about issues li... |
I have Group A, B, C.
My hypotheses are"
1) proportions of C are different from proportions of A (=independance)
2) proportions of C are different from proportions of B (=independance)
3) proportions of A are NOT different from proportions of B (=NO independance)
Is there something like post-hoc contrasts for chi-sq... |
I'm trying to build a prediction model with SVMs on fairly unbalanced data. My labels/output have three classes, positive, neutral and negative. I would say the positive example makes about 10 - 20% of my data, neutral about 50 - 60%, and negative about 30 - 40%. I'm trying to balance out the classes as the cost associ... |
I have a 2x2x2 factorial design with two dependent variables (lets say height and weight). I can examine the effect of the three factors for each dependent variable separately. But I also want to check if height has anything to do with weight? I.e., is the tallest subject the heaviest?
Any idea on how to analyse thi... |
Specifically the Welch's T-Test, but probably any T-Test, requires a value for Mean, Variance and N to be used to calculate the T-statistic and the degrees of freedom. I am concerned about these values if the sample has been bootstrapped (re-sampled with replacement) before using the T-Test. Specifically, I'm concerned... |
I performed a holdout cross-validation analysis on a multilevel model fit. The purpose of this was to show that we didn't have a problem with over-fitting, for which it worked just fine. Now we are writing it up for publication and I need a citation to support my methodology. I am looking for a good canonical statistic... |
I have a data set with high-dimensional feature space. Are there any pre-processing methodologies that can detect outliers from this data set? The outlier, I mean, are the ones that tend to be very different with other data points and can be the ones that generated by improper measurements.
|
I have problem with find ranking of words while computing multiple contents.
I'm splitting each words from the contents except stop words.
I have individual word counting with all contents, i.e total contents count=30, word$_1$ count=some $x$, word$_2$ count=some $y$ and so on.
We cannot consider word occurrence in sep... |
I have a data-analysis problem with two closely-related timeseries. Both are binned in time at the same rate, but one is discrete (takes values in $\mathbb{Z}$), and the other is continuous. I am interested in modeling each of these processes' dependence on a common set of predictors, $X$.
Given $X$, the question I wou... |
I'm trying to investigate the effect on (a) tear resistance and (b) gloss of a piece of film due to additive and extrusion method. I can see that the best results for tear resistance is low additive high extrusion, and the best results for gloss is low additive, low extrusion. Although is there a way to say the best ov... |
I am interested in trying to validate some results from a previous experiment. The experiment involves selecting probes of interest that separate our two populations of interest, e.g. smoker vs. non-smoker, high protein diet vs. low protein diet.
I have called some probes on an initial data set as significant but what ... |
When running the Automatic Linear Modeling function of SPSS version 20, it will return an accuracy value.
The higher the accuracy, the more predictive the model (I assume). However, what does this accuracy really indiciate?
Is it the R2? Adjusted R2? Something else?
|
I am analyzing (in SPSS 19) the data from a field experiment using a Linear Mixed Model with Repeated Measures. When checking the model, I always obtain negative values in the information criteria table. I know the rule of thumb “smaller is better”, but how should these negative values be interpreted? As example, when ... |
We statisticians use many words in ways that are slightly different from the way everyone else uses them. This cause lots of problems when we teach or explain what we are doing. I'll start a list (and now I'll add some definitions, per comments):
Power is the probability of correctly reject a false null hypothesis in... |
I am working on an assignment for a course in statistics, and a part of the assignment is to give the null hypothesis of an experiment. The experiment is as followed (short summary):
A company is testing 3 interfaces for a website. They test the interfaces with 15 students, 5 for each interface, and all 5 have a differ... |
I want to run ordinal logistic regression (OLR) in SPSS. My data include 6 predictor variable (two continuous and 4 categorical ) but my outcome variables are also 6 (categorical-likert scale).
e.g my dependent variable is Business development and 6 likert scale questions were asked for this, increase in profit, sales,... |
I try to figure out how a logistic regression is handling data with a 0/1 dependent variable. 95% of the data are ones. The purpose of the model is to estimate the probability to be in one of the groups. Of course there are several explanatory variables included.
Fitting the model leads to unsatisfactory results, since... |
I have the following probability function:
$$\text{Prob} = \frac{1}{1 + e^{-z}}$$
where
$$z = B_0 + B_1X_1 + \dots + B_nX_n.$$
My model looks like
$$\Pr(Y=1) = \frac{1}{1 + \exp\left(-[-3.92 + 0.014\times(\text{gender})]\right)}$$
I understand what the intercept (3.92) means, but I'm now sure how to interpret 0.014.
Ar... |
I'm using R to provide bootstrap (percentile and t methods) of estimated population totals, using data from a complex survey. It is a stratified survey of tourists expenditure that is weighted to population (the known number of tourists from customs information). I want a confidence interval for total expenditure of ... |
For this question, assume I have a standard deck of cards (52 cards, 13 of each set).
My question is: if I were to randomly draw 7 cards, how would I calculate the probability of at least one of those cards being a Spade?
Then, supposing no spades were drawn, how do I calculate the probability that the next card I dra... |
We designed a RCB experiment and assigned the factor levels to the experimental units randomly inside each block. Let's pretend we changed our mind and we would like to go for a Completely Randomized design. A new completely randomized assignment of factor levels to experimental units is not possible since the experime... |
Does anyone know references for non-asymptotic risk bounds for Gaussian regression. Specifically, I am interested in Bayesian regression with a Gaussian prior on the estimator space, and a Gaussian likelihood. I would like to know any results that bound the difference between the risk of the Bayesian estimator and the ... |
I have 2 daily time-series, each 6 years long. While noisy, they are both clearly periodic (with a frequency of ~1 year), but appear to be out of phase. I would like to estimate the phase difference between these time-series.
I've considered fitting curves of the form $a\sin(\frac{2\pi}{365}t - b)$ to each time-series ... |
Disclaimer: I know absolutely nothing about statistics. I've had trouble searching for answers to my question, as I don't have much knowledge about the terminology of statistics.
I'm currently trying to plot a graph with two sets of values that are widely different. This doesn't really matter, but I'm doing this in Py... |
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