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I'm working on a project where I'm trying to take a pair of documents and find and group (cluster) similar words and phrases between them.
Which algorithm would solve this kind of a problem? I know this is a very mundane and probably subjective question, but I'm new to clustering, and I'm still trying to work my way ar... |
I am a graduate student in computer science. I have been doing some exploratory factor analysis for a research project. My colleagues (who are leading the project) use SPSS, while I prefer to use R. This didn't matter until we discovered a major discrepancy between the two statistical packages.
We are using principal a... |
I have about 400 pieces of silver of different geometric dimensions. They were assigned to six groups and each group went through a series of stress tests, such as bending, pulling, putting in fire for a period of time, etc. The treatments that were given to the six groups were not the same, but fairly similar. The siz... |
(A cross post after finding more appropriate tags here.)
My question is on Bayesian inference of partitioned multivariate Gaussian. To make things easier, suppose there is a 2-dimensional Gaussian,
$$
X_1 \sim N(\mu_1, \sigma^2_1) \\
X_2 \sim N(\mu_2, \sigma^2_2)
$$
with covariance $\sigma_{1,2}$.
Suppose we know $\sig... |
Suppose we are doing a cross sectional study on heart disease in males and females. If $16/10000$ males have heart disease and $10/10000$ females have heart disease, can we conclude that men have a much higher risk of heart disease than women? Why or why not?
I think you cannot since we are comparing proportions. We do... |
I wonder if there's a way to calculate the combined odds ratio for certain SNPs in a meta-analysis of a several GWAS, even when you don't have the SE, neither beta, for each individual study?
Thank you!
|
For a model with a binomial proportion as response variable, which is fitted with according to a binomial distribution, a dispersion parameter $\phi$ can be calculated, which is equal to the sum of the squared Pearson residuals divided by the residual degrees of freedom.
I was following along with an example I found on... |
Given a hierarchical model $p(x|\phi,\theta)$, I want a two stage process to fit the model. First, fix a handful of hyperparameters $\theta$, and then do Bayesian inference on the rest of the parameters $\phi$. For fixing the hyperparameters I am considering two options.
Use Empirical Bayes (EB) and maximize the margi... |
I have been looking into the random trees and decision trees in OpenCv and something that still confuses me is the differences between regression and classification.
Can anyone outline what the differences are, when would one use one over the other?
The reason for me asking is that i am using classification for labelin... |
Is it possible to drop levels that are not used in ggplot2s facets? This is my code:
tab = as.data.frame(cbind(groups = mtcars$cyl, names = row.names(mtcars), val = mtcars$mpg, N = mtcars$disp))
tab$N = as.numeric(tab$N)
ggplot(tab, aes(names,val)) +
geom_point() + coord_flip() +
theme_bw() +
facet_grid(groups ~ .,... |
Is there any advantage of using "central moments" over "moments" when approximating a distribution to a known distribution using moment matching? I have noticed that in lot of papers.
|
I am currently working on a segmented regression model with two variables $(x_i,y_i)$ for $i = 1..N$. The model should take the form:
$y_i = \beta_0 + \beta_1 x_i \quad$ for $x_i < x_{crit}$
$y_i = \alpha_0 + \beta_0 + \beta_1 x_i \quad$ for $x_i \geq x_{crit}$
where $x_{crit}$ is a breakpoint value that has to be dete... |
Context:
I am collecting Twitter data through a source that allows me to take a statistical sample of tweets that match a filter. I want to determine the appropriate sample rate in order to achieve a certain statistical confidence in my estimate of the actual number of tweets that would match that filter.
Sampler deta... |
In matlab, I've ran
[p,stats,~] = anova1(X)
with some samples, and it indicates a significant difference in (at least) 2 means from the samples.
i.e. $p < \alpha$ for some value of $\alpha$.
However, running
multcompare(stats,'alpha',alpha)
doesn't indicate any significant difference between the data sets (i.e. ther... |
Very close to: Finding the Bayesian classifier for a bivariate Gaussian distribution
Can somebody tell me the joint Gaussian of the following two Gaussians
(in which $C_j = C_1 \text{ or } C_2$):
$$p(x|C_1) = \text{N}(μ_1,Σ_1)$$
$$p(x|C_2) = \text{N}(μ_2,Σ_2)$$
where
$$μ_1 = \left[\begin{array}{c}
1\\
1\end{array}\r... |
I don't understand how to interpret the coefficient from a Poisson regression relative to the coefficient from an OLS regression.
Suppose I have time series data, my left-hand side variable is number of games won per year, and my main right-hand side variable is NASDAQ value. If my preferred specification is to interpr... |
For example, one wants to predict house prices and have two input features the length and width of the house. Sometimes, one also includes 'derived' polynomial input features, such as area, which is length * width.
1) What is the point of including derived features? Shouldn't a neural network learn the connection betwe... |
In a linear multiple regression equation, if the beta weights reflect the contribution of each individual independent variable over and above the contribution of all the other IVs, where in the regression equation is the variance shared by all the IVs that predicts the DV?
For example, if the Venn diagram displayed bel... |
I have some problem with the transformation of my data. This is my project in my regression class, and we're asked to run our data and satisfy all the possible assumptions, until we can chose a model. Which we're going to use for prediction. Now, I tried all possible transformations, but It doesn't give me any solution... |
I'm currently writing a lab report on Atwood's machine, and the gist of it is that $a=a_{g}\tfrac{\left ( m_{2}-m_{1} \right )}{\left ( m_{2}+m_{1} \right )}$.
We're holding $\left (m_{2}+m_{1} \right )$ and $a_{g}$ constant, where $a$ is our dependent variable and $\left (m_{2}-m_{1} \right )$ is our independent vari... |
I'm trying to do a regression with data over time, and where I suspect there may be a lag component in the relationship between my dependent and independent variables. I've actually found some data online here that provides a good minimal example
sales<-data.frame(Quarter=1:8, Sales=c(16850, 12010, 14740, 13890, 12950... |
I am using the Zipf-Mandelbrot distribution in my work according to its definition on wikipedia: http://en.wikipedia.org/wiki/Zipf%E2%80%93Mandelbrot_law.
I would like to obtain the citation of the paper or the book that introduce it.
|
I need to determine if there is any relationship between two count variables.
I have 60+ observations for 4 variables and I want to see if any of the pairs of these variables are significantly correlated with one another.
Mostly I use R, so forgive me if you're not familiar.
I have been using the cor(...,method="pear... |
I am running 3 models on 3 subsets of the same data. The set up is as follows:
Outcome (DV) is binary categorical
Time (IV) is repeated twice (pre and post)
Treatement (IV of interest) is binary categorical
I am interested to know if at time 2 treatment has had an effect on outcome. I used the lme4 package and used... |
I have some data (a set of numbers) and I want to compare them with the normal distribution using QQ-plot. The only statistical tool that I am aware of is Octave but Octave doesn't draw the reference line.
As can be seen in the above picture the x-axis has a range from - 3 to 3 but the y-axis has a range from 20 to 14... |
In May 2010 Wikipedia user Mcorazao added a sentence to the skewness article that "A zero value indicates that the values are relatively evenly distributed on both sides of the mean, typically but not necessarily implying a symmetric distribution." However, the wiki page has no actual examples of distributions which br... |
Much like with regression, handling binary dependent variables in SEM requires special considerations. In particular, some of these are noted on Dave Garson's Structural Equation Modeling and include:
Polychoric correlation. LISREL/PRELIS uses polyserial, tetrachoric, and polychoric correlations to create the input c... |
I do not fully understand how to interpret the difference between two statistical models where they only differ based on whether a certain variable is included on the right hand side.
If the results do not change much, then do we say that that this omitted variable has little effect on the result?
If the coefficient o... |
I have two timeseries, y[t] and x[t]. A domain expert tells me that y[t] should be a linear combination of past values of x[t] up to a certain horizon, i.e.
y[t] = a[0]*x[t] + a[1]*x[t-1] + ... + a[n]*x[t-n]
How do I estimate the a[i] coefficients in R? Indeed, what is the proper name for this kind of model?
|
Suppose we want to model the temperature ($1$ = hot, $0$ = cold) of 5 regions over the following time periods: 1 month, 6, months, and 4 years. Suppose a predictor variable is $X$ (amount of deforestation, 1 = a lot, 0 = very little). In modeling the main effect (deforestation), should we include time as a predictor?
|
I am working on Lasso problem and the selection of the optimal tuning parameter with $k$-fold procedure, say $k=10$.
Since this procedure relies on random subsampling, value of the optimal parameter will change each time I repeat the procedure. As an example, it can be 0.32, then 0.41, then 0.29, etc.
Two questions:
... |
I don't know if this is a suitable question here. I have data from 2 groups, neutral and positive.
Here how the data looks like
A 02.840 00.960 00.950 00.995 00.995 00.602 1
B 04.730 01.000 01.000 00.999 01.000 01.000 1
C NULL 00.970 00.005 00.078 00.987 00.000 0
D NULL 01.000 01.000 00... |
I and my friends just had a little discussion whether the events are independent or dependent if they have no outcome in common. I thought that they have to be independent. When two events are independent, then $P(A)=P(A\mid B)$. Is the information given in the question enough to establish this?
If you look at it as a ... |
I have an array of $n$ real values, which has mean $\mu_{old}$ and standard deviation $\sigma_{old}$. If an element of the array $x_i$ is replaced by another element $x_j$, then new mean will be
$\mu_{new}=\mu_{old}+\frac{x_j-x_i}{n}$
Advantage of this approach is it requires constant computation regardless of value ... |
Does "benchmarking" and "post-stratification" describe exactly the same process? The Wikipedia article on Statistical Benchmarking claims it is; however, the article on Sampling also mentions "poststratification" but doesn't link to "benchmarking".
Perhaps there are other applications of benchmarking besides post-strat... |
I want to show that my data cannot fit a given distribution (in my case it's the Pareto type II distribution). I did a P-P plot, i.e on the y-axis I plot my sorted experimental data and on the x-axis the inverse of the theoretical cdf.
I added my Matlab code below in case my explanation is not clear.
Most of the time... |
I'm using scikit learn's linear model to do ridge regression.
Ridge regression penalizes parameters for moving away from zero. I want to penalize for moving away from a certain prior, with each parameter having a different prior.
Is this possible with scikit learn's linear model? I know there's a BayesianRidge module ... |
significant lags in causality test?
[Cross-posted to R-Sig-Finance]
Hi all,
I have a question regarding Granger causality test.
I have searched on Internet intensively and extensively and have used both the "grangertest" function in lmtest package and the "causality" function in vars package.
If we see that x causes y... |
Does anybody know the way to construct a Bayesian classifier in R for two bi-variate gaussian distributions of which the means and variances are known? The two classes are equi-probable and the variables are independent from each other.
Any help is deeply appreciated.
|
A marginal model accounts for the correlation within each cluster. A conditional model also takes into account the correlation within each cluster.
My questions are:
Does a marginal model models main effects across a population whereas a conditional model models main effects within a cluster and across a population? ... |
I am doing a thesis project evaluating differences in attitudes towards trans students. The only manipulation was which vignette participants read. My variables are as follows:
DV1: First impressions score (continuous)
DV2: Social distance score (continuous)
IV: description of the vignette character: transsexual, cros... |
What relationship does a negative binomial regression have to heteroskedasticity and if one still needs to check and/or correct for it how would this be done?
|
Lets assume I have a survival analysis study with an exposure, two covariates, and two time related variables. Say date of diagnosis and date of death. Combined, the two time related variables will be used to make a survival time variable: t = date of death - date of diagnosis .
The problem is that some of those date v... |
I have seen it claimed in Hosmer & Lemeshow (and elsewhere) that least squares parameter estimation in logistic regression is suboptimal (does not lead to a minimum variance unbiased estimator). Does anyone know other books/articles that show/discuss this explicitly? Google and my personal library have not helped me ... |
I am analyzing the influence of social capital on household income. I have collected data through a questionnaire survey for my study.Different dimensions (variables) of social capital were measured using 5-point multiple likert items.The scores on each item was summed up to obtain the single value for each variable.No... |
We (my team) are building a robot which will navigate around an arena.
The robot uses a camera to determine its position based on markers on the wall. We have tested this and found it can determine position well when close to the wall. However, at further distances, the markers appear to move randomly by single pixels ... |
I have two sample means from two different samples. I purport that the true population means are identical.
$H_{0}$: $\mu_{1}=\mu_{2}$ and
$H_{1}$: $\mu_{1}\ne\mu_{2}$
What significance test would I use to determine evidence for or against the null hypothesis?
Sample 1: {4,3,1,3,5,2,2,3,5,3}
Sample 2: {5,3,2,2,3,3,1,4,... |
Given, $p_{ij}=\frac{|A_i|+|A_j|}{|A_i\cup A_j|}$ for sets $A_i$,$A_j$ $\forall i\not=j ,\forall i \in \left \{ 1,2...n \right \} $ and given the fact that $|A_i \cap A_j|>0$ for all $A_i,A_j$: it is clear that $p_{ij}$ > 1.
$p_{ij}\in\mathbb{R}^+, \forall i,j$ and $|A_i|\in\mathbb{Z}^+$ are random variables (observ... |
I know that distribution of sample variance
$$
\sum\frac{(X_i-\bar{X})^2}{\sigma^2}\sim \chi^2_{(n-1)}
$$
$$
\sum\frac{(X_i-\bar{X})^2}{n-1}\sim \frac{\sigma^2}{n-1}\chi^2_{(n-1)}
$$
It's from the fact that $(X-\bar{X})^2$ can be expressed in matrix form,
$xAx'$ (where A: symmetric), and it could be again be expres... |
In my study I have several predictor variables as well as dependent variables/outcomes. I don't have much theoretical pressure to choose any variable over another, making decisions about regressions frustrating. So I ran the correlations between all variables, IVs and DVs to see which had relationships. Is this frowned... |
I'm estimating systems of simultaneous eqns in R, and trying to impose homogeneity and symmetry restrictions on the equations. I'm using the "systemfit" package. I've managed to impose one restriction on one of the eqns using 'restrict.matrix' (as you see from the example below). How do I impose all restrictions at the... |
I understand the rules for combining experimental errors in sums, differences and ratios (as explained here), but what happens to an experimental error when you average it?
Say, ruler measurements of the length of beetles that are all values like 12.3 cm $\pm$ 2mm.
I can find plenty of explanation on the web about how ... |
Is there any command-line tool that accepts the flow of numbers (in ascii format) from standard input and gives the basic descriptive statistics for this flow, such as min, max, average, median, RMS, quantiles etc? The output is welcome to be parseable by the next command in command-line chain. Working environment is L... |
Is there any naming convention regarding the hat and the tilde symbol in stats?
I found $\hat{\beta}$ is describing an estimator for $\beta$ ( Wikipedia ) But I also found $\tilde{\beta}$ is describing an estimator for $\beta$ (Wolfram ).
Is there any difference in the meaning?
On the web I found kind of a difference ... |
I have a set of measurements which is partitioned into M partitions. However, I only have the partition sizes $N_i$ and the means $\bar{x}_i$ from each partition. Because all measurements are assumed to be from the same distribution, I believe I can estimate the mean of the population, $\bar{y}$, and standard deviation... |
According to Regression Analysis by Example, the residual is the difference between response and predicted value, then it is said that every residual has different variance, so we need to consider standardized residuals.
But the variance is for a group of values, how could a single value have variance?
|
Is it possible that two random variables have the same distribution and yet they are almost surely different?
|
Suppose that I have two distance matrices for the same set of items.
By a distance matrix I mean a square matrix whose (i,j)th entry holds the distance (in terms of cosine similarity) between ith and jth items. The ith and jth items are the same items in both matrices. Such a situation might happen when we gather infor... |
I have a reasonable understanding of why multicollinearity is a problem is regression models, along the lines of this excellent post.
To summarise my understanding, for a regression model of $y = \alpha + \beta_1x + \beta_2z$ (where $x$ and $z$ are correlated), beta coefficient estimates (as well as being unstable) are... |
I've used Stata 12 to estimate a hierarchical logit model (xtmelogit) with random intercepts. The outcome is incarceration (1=yes) for a series of convicted criminal offenders. There are a slew of interaction terms and I'm trying to understand these by looking at the predicted odds at different levels of X while hold... |
Suppose $X \sim U(0,1)$, and $Y[x] = g(x)$ where $g(.)$ is some complicated function. I want to calculate/plot the density of $Y$. I can do this analytically for simple enough $g$.
I can also generate some large number $N$ samples of $X$ from the stardard uniform, calculate $y_i = Y(x_i)$ for each sample $x_i$, and the... |
I am having some trouble trying to decide what measure of inter-rater reliability to use in a study. Part of a larger study involves accurately determining when participants began (onset) and stopped (offset) writing. I have video footage which captures the writing, and can determine the time of onset/offset to the n... |
I want to know the approaches people use to forecast lets say unemployment rate .... By itself it might not fit a time series model (ARMA) very well as the trend is dependent on many external factors.
My hypothesis is that if a time series for the target doesn't fit well, but some of the underlying causal variables ca... |
How should I calculate sample size for a clinical trial when I need a power of 80% and I predict an effect size to be at lest 0.5? do I need to estimate the mean of outcome as well?
|
I remember seeing/reading somewhere that for multiclass SVMs with unbalanced data, there was a way to determine the class weights from the training data (rather than X validation). Does anyone know what the method is or what paper its from?
Thanks
|
I was reading the Wikipedia article on Robust Statistics: http://en.wikipedia.org/wiki/Robust_statistics#Properties_of_M-estimators
What is meant by the distribution of an estimator, as used here,
It can be shown that M-estimators are asymptotically normally
distributed, so that as long as their standard errors can ... |
I was wondering if anybody had any insight or intuition behind the difference between the Variation of Information and the Rand Index for comparing clusterings.
I have read the paper "Comparing Clusterings - An Information Based Distance" by Marina Melia (Journal of Multivariate Analysis, 2007), but, other than noticin... |
When I run multinomial logistic regression with some of the explanatory variables as categorical, my algo (glm) turns them in binary variables, automatically. For examples if one categorical variable X has three values a, b anc c, then my output shows cofficient and t-values for x.a, x.b and x.c.
But in fact I want t-... |
Please apologize my butchering of statistical lingo :) I have found a couple of questions on here that are related to advertising and click through rates. But none of them helped me very much with my understanding of my hierarchical situation.
There's a related question Are these equivalent representations of the same ... |
This is a multi-response linear regression experiment. I generate a random matrix of gaussian noise $\mathcal{N}(0,1)$ sized 10x6 called $Y_N$. I then generate an independent response $X$ via either uniform or gaussian noise, 10x1. I then regress $X$ on $Y_N$, generating $\hat{Y}$. I obtain my residuals, $Y_{res}$, by ... |
I ran an experiment and obtained the points shown in black below.
I would like to smooth the curve or fit (something like the red curve) in order to identify the elbow.
The problem is that the experiment is too expensive and there is a large amount of variance in the obtained points.
I tried fitting a second degree ... |
I am working on an assignment involving a logistic regression model, where I need to plot the pearson standardized residuals against one of the predictors. Here's the basic setup:
model <- glm(outcome ~ predictor1 + predictor2, family=binomial(logit))
res <- residuals(model, "pearson")
When looking at the residuals' d... |
Cohen's d is a measure of effect size calculated as:
$d = (x_1-x_2) / \sigma_{\text{pooled}}$
where $x_1$ is the mean of one group, $x_2$ is the mean of a second group, and $\sigma_{\text{pooled}}$ is the pooled standard deviation.
Let us say that one treatment has an effect size of 0.6 and another treatment has an aff... |
I have a large survey in which students were asked, among other things, their mother's level of education. Some skipped it, and some answered wrongly. I know this, because there a sub-sample of the initial respondents mother's were later interviewed, and asked the same question. (I'm sure there is some, smaller amou... |
From an answer in a previous question, I was directed toward the Halton sequence, for creating a set of vectors that covered a uniform sample space fairly evenly. But the wikipedia page mentions that higher primes especially are often highly correlated early in the series. This seems to be the case for any pair of high... |
I have problems in using the cor() and cor.test() functions.
I just have two matrices (only numerical values, and the same number of
row and columns) and I want to have the correlation number and the
corresponding p-value.
When I use cor(matrix1, matrix2) I get the correlation coefficients for all the cells.
I just wa... |
Suppose, we have a set of measurements of some quantity in some units of measurement. We also have a nice model that heavily relies on the properties of the Gaussian distribution. The model is tailored for data in some specific units of measurement with some physical meaning behind (like watt, ohm, etc.). It turns out ... |
How to calculate R-squared ($r^2$) statistic in R for loess and/or predict function output?
For example for this data:
cars.lo <- loess(dist ~ speed, cars)
cars.lp <- predict(cars.lo, data.frame(speed = seq(5, 30, 1)), se = TRUE)
cars.lp has two arrays fit for model and se.fit for standard error.
|
I need help, since my skills and knowledge in statistics are really limited.
Using Pearson correlation I found that there is some relationship between a binary one and a second variable taking values between 1 and 4. So now I want to understand if there are significant differences between the two groups defined by the ... |
I have been working on importance sampling fairly closely for the past year and have a few open-ended questions that I was hoping to get some help with.
My practical experience with importance sampling schemes has been that they can occasionally produce fantastic low-variance and low-bias estimates. More frequently, ho... |
Considering the high number of car accidents, it must be around 5%, right?
|
I have two sets of data. The one is daily temperature data and another is 16-day vegetation observation data (value of Jan 1, Jan 17 etc), throughout a year. But I need daily values of vegetation observation data. How to obtain daily value from 16-day vegetation data?
|
I have a data set and I have to fit this data set with a stable distribution. The problem is that the stable distributions are known analytically only in the form of the characteristic function (Fourier transform). How can I do this?
|
Are there any non-identical distributions which happen to have the same moment-generating function?
|
I frequently measure multiple variables, in multiple replicates, at many sites. For instance, I might measure bacterial abundance and bacterial growth rates, each in 3 replicates, at many sites. Each replicate is independently sampled and each variable is measured in a different sample (i.e., I can't measure both bacte... |
Will running multiple regression including 2 independent variables give the same output for each independent variable if we run linear regression using the same independent variables separately/individually?
|
somebody please prove or disprove
$P(x|y)=P(x|z)/P(y|z)$
I have tried to plug in numbers with example in Wikipedia, for example,
$A$ is outcome number of dice 1
$B$ is outcome number of dice 2
$X$: event of $A=2$
$Y$: event of $A+B \leq 5$
$Z$: event of $B=2$
$P(x|y) = 3/10$ ,
$P(x|z) = 1/6$ , and
$P(y|z)= 3/6$
Quest... |
I have one dependent categorical variable and other many explanatory categorical variables. The number of nominal values for any of these categorical variables may fall in range of 5-100. My objective is to explore the relationship between dependent categorical variable and any one of explanatory variable and to find o... |
I asked a question but it was a bit long and confusing so I will attempt to keep this shorter and simple (original post https://stats.stackexchange.com/questions/24971/mixed-effects-model-equations)
I am basically looking to see which factors (e.g. A, B, C such as habitat type, site, disturbance rate) most affect the ... |
First please forgive me of using this non-mathematical terminology in the title.
Assume we have two series of real numbers $X_1, X_2, \ldots, X_M$ and $Y_1, Y_2, \ldots, Y_N$ where it is possible for $X_i=X_j$ and $i \neq j$. Now if we combine series $X$ and $Y$, the resulting set of real numbers $X_1, X_2, \ldots, X_... |
Given an arbitrary discrete distribution and an observed distribution coming from a Monte Carlo simulation, my goal is to be able to say whether or not the observed distribution is the same is the given distribution such that I correctly identify a distribution which is different with probability greater than 1 in 10,0... |
I want to construct a path analysis model that can account for measurement error in totally aggregated parcels, which refer to parcels where all of the items in a scale are summed or averaged. If I am not mistaken, Bollen (1989) advocates the following formula for computing the error variance of each parcel:
$$\big(1 -... |
I've heard a couple of definitions of a Bayesian plot, but I am not 100% sure what it is and whether it is possible to plot this in an R.
An example of the plot is here: http://www.springerimages.com/Images/MedicineAndPublicHealth/1-10.1007_s11307-008-0154-3-1
In this particular example there are four different tests, ... |
I am trying to classify texts using a bag of words algorithm. My feature vector is thus a large array of words. In order to build my feature vector, I parse the sample and put a one in the index corresponding to the word found. I use sparse format to represent the feature vectors. A little example to clarify:
feature v... |
It is fairly easy to figure out what is the average number of rolls it would take to roll all faces of a die [$1 + 6/4 + 6/4 + 6/3 + 6/2 + 6/1 = 14.7$], but that got me thinking of a seemingly more complicated problem.
If you roll a die 1-5 times, the odds of all faces showing is obviously 0.
If you roll a die 6 times,... |
Is there a way of performing HAC robust standard errors in SPSS?
|
I'm trying to sort out two different uses of the term "compound distribution" and figure out the relationship.
The Wikipedia article on compound distribution -- which I wrote -- defines a compound distribution as an infinite mixture, i.e. if $p(x|a)$ is a distribution of type F, and $p(a|b)$ is a distribution of type G... |
I have a time series (let's say $X_1$ to $X_n$), and I need to predict the next sample (let say $X_{n+1}, X_{n+2},\dots, X_{n+k}$) using model such as neural network, or multiple linear regression. At time n, I have all the sample from $X_1$ to $X_n$, and need to predict $X_{n+1}$; at time $n+1$, I have all the sample ... |
I'm pretty new to machine learning so wondering whether someone can help check my thinking or point me in the right direction!
I need to create a classifier which can predict an outcome for a person based on attributes about that person + multiple time series containing activity data for each person.
After a lot of res... |
I am trying to fit data with a GLM (poisson regression) in R. When I plotted the residuals vs the fitted values, the plot created multiple (almost linear with a slight concave curve) "lines". What does this mean?
library(faraway)
modl <- glm(doctorco ~ sex + age + agesq + income + levyplus + freepoor +
... |
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