instruction stringlengths 9 38.7k |
|---|
Even simple models in probability theory can be quite confusing (e.g. drawing something with or without returning it, conditional probabilities, one and only one outcome, at least one outcome asoasf...)
In other areas of mathematical modelling (e.g. differential equations) you often have powerful and easy to use modell... |
As a follow up to my previous question, I learned that the chi square test can be used to compare expected and observed frequency distributions. But ...
Suppose I have the following data table in CSV, which surveys people on their fruit preferences in three cities (total people surveyed is different in each city):
appl... |
In a (one or multi) way anova model, once a new individual is assigned to a treatment, the predicted value for him is calculated using the coefficients of the ANOVA model (simply assigning the treatment mean value to the individual).
How should I construct a confidence (or prediction) interval for that predicted value... |
What are some hot topics that mathematical statistics researchers are studying now?
|
In Statistical Modeling: The Two Cultures Leo Breiman writes
Current applied practice is to check the data model fit using goodness-of-fit tests and residual analysis. At one point, some years ago, I set up a simulated regression problem in seven dimensions with a controlled amount of nonlinearity. Standard tests of g... |
Is there a possibility to use R in a webinterface without the need to install it?
I have only one small script which I like to run but I just want to give it a shot without a long installation procedure.
Thank you.
|
I'm in the process of learning R, in the hope of replacing everything I do in SPSS/Sigmplot with R. It's going well so far :) I've got to the point of running a repeated-measures ANOVA, but have come unstuck when trying to plot the results
I've worked out how to plot a set of means using ggplot2, but now I'm unsure of ... |
I ran a multinomial logit model in JMP and got back results which included the AIC as well chi-squared p-values for each parameter estimate. The model has one categorical outcome and 7 categorical explanatory vars.
I then fit what I thought would build the same model in R, using the multinom function in the nnet packag... |
If the correlation between demographic dissimilarity and satisfaction is $r=.-14$ and the partial correlation, with career development partialled out, between demographic dissimilarity and satisfaction is $r=-.06$ across a very large sample of size $n$, what is the appropriate test to determine if these correlations ar... |
I'm hoping to hear from someone who has worked on mouse models or similar biological analyses where there is a tendency to run 'replicates' of an experiment. I know multiple testing is a sizeable kettle of fish which is definitely relevant to this discussion. I have some applications for projects where they talk about ... |
Under what circumstances would using regression with two given variables not increase accuracy of prediction?
|
I was given the following question:
A survey found that 89% of a random sample of 1024 American adults approved of cloning endangered animals. Find the margin of error for this survey if we want 90% confidence in our estimate of the percent of American adults who approve of cloning endangered animals.
I know that for 9... |
Possible Duplicate:
Threshold for correlation coefficient to indicate statistical significance of a correlation in a correlation matrix
Context
I am doing an exploratory study to investigate the relationship between a drug (actually measured in two ways - by direct and indirect methods) and 15 various parameters. Th... |
Is it possible to use a continuous predictor in Bugs? The simplest way of doing this would be turning the size variable in alligators example from discrete to continuous.
Both Winbugs and JAGS examples use combination of values of covariates as indices as in
X[i,j,] ~ dmulti( p[i,j,] , n[i,j] );
where i is the lake... |
... (optional) within the context of Google Web Optimizer.
Suppose you have two groups and a binary response variable. Now you get the following outcome:
Original: 401 trials, 125 successful trials
Combination16: 441 trials, 141 successful trials
The difference is not statistically significant, however one can calcu... |
I have a time series (X) representing a natural phenomenon (wind speed, measured every 15 minutes) and I have to create similar time series (up to 20, Xdi, i=1,...,20) with the same structure (same average, same standard deviation, same percentiles distribution...) but with a predetermined correlation (about 0.7) betwe... |
I am attempting to build a Multinomial Logit model with dummy variables of the following form:
The dependent variable represents 0-8 discrete choices.
Dummy Variable 1: 965 dummy vars
Dummy Variable 2: 805 dummy vars
The data set I am using has the dummy columns pre-created, so it's a table of 72,381 rows and 1770 co... |
I have a set of sea surface temperature (SST) monthly data and I want to apply some cluster methodology to detect regions with similar SST patterns. I have a set of monthly data files running from 1985 to 2009 and want to apply clustering to each month as a first step.
Each file contains gridded data for 358416 points ... |
I'm interested in assessing model performance on data with an ordinal categorical dependent variable. For my use case, the ideal metric would:
Not assume equal intervals between classes or that recoding to a continuous scale is appropriate
Be scale independent
Give preference to models that rank the outcomes a... |
I'm trying to understand the following claim:
if the $t$-statistic is greater than
zero, it indicates that the variable
is explosive... but does that mean it
has unit root?
In the context of Dickey Fuller test.
|
How would you go about explaining "Stambaugh Bias" in simple relatively non-technical language?
|
First of all, I’m new to statistics and this is the first time I am trying to apply it to a real world problem.
I am doing analysis of a series of observations of a variable over all weeks of a year. During certain weeks an event happened that I believe has impacted the variable and I want to check for this.
The value... |
I have a set of data that are binomial, and am comparing them across 9 years. The first 5 years have low sample sizes ($~n=20$) and the last 4 have $n>100$. I've run a glm in R with the family set to "binomial", and the results look reasonable.
However, when I did the multiple comparisons afterwards using the multcomp ... |
I often hear that post hoc tests after an ANOVA can only be used if the ANOVA itself was significant.
However, post hoc tests adjust $p$-values to keep the global type I error rate at 5%, don't they?
So why do we need the global test first?
If we don't need a global test is the terminology "post hoc" correct?
Or ar... |
I have a large set of customer data. For these customers, I have devised a customer loyalty score which is a measure of the loyalty of the customer. I want to find the features that are strongly associated/correlated with this score. Features could be number of purchases at various merchant types.
One obvious answer... |
I have trained an SVM Regression model using training data, $x_1,x_2,\dots,x_N$.
I want to perform active learning to improve the model; i.e., I want to add more samples to the training data and relearn a better model, and to choose these new samples in such a way as to maximize the resulting model performance.
For an ... |
I am about to dive into learning R and my learning project will entail applying mixed- or random-effects regression to a dataset in order to develop a predictive equation. I share the concern of the writer in this post
How to choose nlme or lme4 R library for mixed effects models? in wondering whether NLME or LME4 is ... |
A typical image processing statistic is the use of Haralick texture features, which are 14.
I am wondering about the 14th of these features: Given an adjacency map $P$ (which we can simply view an the empirical distribution of two integers $i,j < 256$), it is defined as: the square root of the second eigenvalue of $Q$,... |
I have a question which asks:
Determine those values of the positive integer n for which a finite nth moment of X about zero exists.
How should I approach this question? Does it depend on the numbers of variables in X? I think that a first moment exists if the mean exists, and the second moment exists if the variance... |
Could anyone provide some suggestions on how to generate over-dispersed counts data with serial correlations? I am using R software to conduct a simulation study. Any references on this subject will be much appreciated.
Thanks for your help.
|
For many years I have been conducting t-tests on response to mailing activity. Recently I was challenged that we should infact be conducting tests on profit rather than response.
So, let me put this in context. If you have two groups of customers of sample size 10,000 each that you were mailing two different offers. On... |
Given a data-frame:
d1 <-c("A","B","C","A")
d2 <-c("A","V","C","F")
d3 <-c("B","V","E","F")
d4 <-c("A","B","C","A")
data.frame(d1,d2,d3,d4)
d1 d2 d3 d4
1 A A D A
2 B V B B
3 C C C C
4 A F A A
Also given that each row may have a unique pattern such that the occurrence of the values A,D,A (first row) r... |
Most clustering algorithms I've seen start with creating a each-to-each distances among all points, which becomes problematic on larger datasets. Is there one that doesn't do it? Or does it in some sort of partial/approximate/staggered approach?
Which clustering algorithm/implemention takes less than O(n^2) space?
Is ... |
I asked a question on StackOverflow for which I was suggested to use Kalman Filter. The question is as follows:
https://stackoverflow.com/questions/5726358/what-class-of-algorithms-reduce-margin-of-error-in-continuous-stream-of-input/5728373#5728373
A machine is taking measurements and
giving me discrete numbers
c... |
Rob Tibshirani propose to use lasso with Cox
regression for variable selection in his 1997 paper
"The lasso method for variable selection in the Cox
model" published in Statistics In Medicine 16:385.
Does anyone know of any R package/function or syntax in R that
does lasso with a Cox model?
|
I want to test the hypothesis of a decreased level of vitamin D in diabetic subjects. For this I have recorded blood glucose and vitamin D levels in 40 cases and 40 controls.
What kind of statistical test can I use to the above hypothesis?
|
Let's say I have two time series, one of which updates more frequently than the other:
$x_0,x_1,x_2,\dots,x_t,\dots$
$y_0,y_{10},y_{20},\dots,y_{10t},\dots$
I want to fit a model to this that predicts $y$ from $x$ (and possibly from previous values of $y$) at each of the values $1,2,3,\dots$, i.e. it gives a prediction... |
Possible Duplicate:
Supervised learning with “rare” events, when rarity is due to the large number of counter-factual events
I am trying to predict diabetes using the BRFSS dataset by using a supervised learning classification model. But I see that the target variable which is having diabetes or not is skewed. That ... |
I have the following data, representing the binary state of four subjects at four times, note that it is only possible for each subject to transition $0\to 1$ but not $1\to 0$:
testdata <- data.frame(id = c(1,2,3,4,1,2,3,4,1,2,3,4,1,2,3,4,1,2,3,4),
day = c(1,1,1,1,8,8,8,8,16,16,16,16,24,24,24,24,... |
I'm trying to understand matrix notation, and working with vectors and matrices.
Right now I'd like to understand how the vector of coefficient estimates $\hat{\beta}$ in multiple regression is computed.
The basic equation seems to be
$$
\frac{d}{d\boldsymbol{\beta}} (\boldsymbol{y}-\boldsymbol{X\beta})'(\boldsymbo... |
I performed a survey using a Likert 1 to 5 scale (totally agree/agree/neutral/ disagree/totally disagree) on 12 questions which are split into 3 statements which the respondent places a value of between 1 to 5 dependent on how much they agree or disagree - there are 36 statements in total.
Respondents:
Group 1 ... |
Does anyone know of a good resource listing known tricks (with examples?) for calculating closed form expressions from messy expectations? (e.g., moment generating function, law of iterated expectations, change of measure, etc.)
In a different setting, I've found Summary of Rules for Identifying ARIMA Models tremendou... |
I want to compare if three groups are different by a non-parametric test. Now..., the problem is that two groups are paired (prior to treatment and one-year after treatment), and the (reference) group is other healthy individuals.
Is there a simple solution? I am using R,
|
Consider data where each observation was generated as follows.
We draw $Z_1,...,Z_m$ from some distribution. (Possibly they're independent or related in some other simple way.)
Next, based on the $Z_1,...,Z_m$, we choose a sequence $0=I_0 < I_1 < ... < I_N=m$ so that, for each $k$, (i) $I_k-I_{k-1}$ is not too small a... |
I got some nice data on multi-environment trials (MET) data for genotype evaluation and would like to use some new developed techniques as discussed in Smith et al. 2005. I'm specifically interested in Factor Analytic (FA) structure. Authors mentioned codes for these methods will be available on request.
There are now... |
I am trying to use Maximum Likelihood Estimation to learn the structure of a DAG, G.
How is the number of free parameters of G calculated to compare the complexity of different graphical models?
Is it based on one of the following, or something else?
Number of edges in the graph
Maximum number of possible edges in the... |
Assume I have a trading system that I'm evaluating over a three-year period. The returns are 25%, -40% and 25%. Empirically, I can see that this system loses because at the end of three years, I have less than when I started.
Wikipedia defines expected return as follows:
E(R)= Sum: probability (in scenario i) * the re... |
I have some data that is highly correlated. If I run a linear regression I get a regression line with a slope close to one (= 0.93). What I'd like to do is test if this slope is significantly different from 1.0. My expectation is that it is not. In other words, I'd like to change the null hypothesis of the linear regre... |
In my elementary statistics course, I learnt how to construct 95% confidence interval such as population mean, $\mu$, based on asymptotic normality for "large" sample sizes. Apart from resampling methods (such as bootstrap), there is another approach based on "profile likelihood". Could someone elucidate this approach?... |
Do there exist any systems for symbolically solving expectations?
This is sort of a follow-up to my question List of Tricks for Solving Messy Expectations? Basically, I'm looking for ways to solve a messy expectation after I've exhausted all obvious routes.
EDIT: BACKGROUND
I'm trying to solve the following for $\alp... |
Can somebody give me references (book/online resource) on using R for Marketing Mix Modelling?
|
I am trying to write a prediction algorithm for a set of temperature data. I settled on Holt-Winters since it seemed to be a simple time series prediction algorithm and I can easily code it up in python to understand what is going on with it.
When I am plotting the smoothing function as it learns this is how it looks.... |
We have data on the day in which a butterfly pupates (forms a cocoon) in the summer/fall of 2 different pairs of years (2005-2006 vs 2009-2010). At the time that the pupa forms it can either be in diapause (suspended animation) or not.
Individual butterfly caterpillars were randomly selected from a wild population a... |
I need some resources to get started on using neural networks for time series forecasting. I am wary of implementing some paper and then finding out that they have greatly over stated the potential of their methods. So if you have experience with the methods you are suggesting it will be even more awesome.
|
While studying machine learning, I've read the following statement:
The kernel $K(x,y)=(x\cdot y+1)^d$ , for $x, y \in \mathbb{R}^p$, has $M={p+d \choose d}$ eigenfunctions that span the space of polynomials in $\mathbb{R}^p$ of total degree $d$.
I do not understand how does the $M={p+d \choose d}$ come from? What do... |
I have 1000 data for two continuous variables (pressure and temperature). I'd like to calculate Bayesian probability between two variables.
In other words, I would like to determine probability that temperature will increase/decrease if pressure is changed?
|
I tried clustering a set of data (a set of marks) and got 2 clusters. I would like to graphically represent it. Bit confused about the representation, since I don't have the (x,y) coordinates.
Also looking for MATLAB/Python function for doing so.
EDIT
I think posting data make the question clearer. I have two clusters ... |
Where can I obtain more weather data?
NOAA has some:
http://weather.noaa.gov/pub/SL.us008001/DF.an/DC.sflnd/DS.synop/
http://weather.noaa.gov/pub/SL.us008001/DF.an/DC.sflnd/DS.metar/
http://weather.noaa.gov/pub/SL.us008001/DF.an/DC.sfmar/DS.dbuoy/
http://weather.noaa.gov/pub/SL.us008001/DF.an/DC.sfmar/DS.ships/
... |
Let's say I have two regression models, one with three variables and one with four. Each spits out an adjusted r^2, which I can compare directly.
Obviously, the model with the higher adjusted r^2 is the better fit, but is there way to test the difference between the two adjusted r^2 and get a p-value?
I know you can d... |
I tried CorrelationFunction[Transpose[{data,data}]][[All,1,2]] but it doesn't work! I mean the results are identical with those if I run CorrelationFunction[data].
|
Consider a vector of parameters $(\theta_1, \theta_2)$, with $\theta_1$ the parameter of interest, and $\theta_2$ a nuisance parameter.
If $L(\theta_1, \theta_2 ; x)$ is the likelihood constructed from the data $x$, the profile likelihood for $\theta_1$ is defined as $L_P(\theta_1 ; x) = L(\theta_1, \hat{\theta}_2(\the... |
I'm trying to use the EM cluster algorithm, provided by the software Weka, to classify my data and it only finds one cluster.
Could I interpret this as there are no ways to distinguish the instances in my sample?
This is a result that is coherent with others analysis that I'm doing to the data, but I don't know if... |
I have performed a Cochran's Q test for a within-subjects experimental design with 3 conditions and 36 participants with a dichotomous dependent variable.
I found a (just) statistically significant effect ($\chi^2$ = 6.00, df = 2, p = 0.04979) and would like to also report the effect size, but haven't been able to find... |
Hey, im a beginner to R and trying to run pvclust so as to test a cluster solution.
I've managed to load data and run the heirachical cluster, however the code i find online for running pvclust is constantly producing errors - just wondering if someone can point out where I'm going wrong...
here is my code (data alread... |
I have a "basic statistics" concept question. As a student I would like to know if I'm thinking about this totally wrong and why, if so:
Let's say I am hypothetically trying to look at the relationship between "anger management issues" and say divorce (yes/no) in a logistic regression and I have the option of usin... |
I have a set of variables for building credit scorecards with logistic-regression. I need to bin some variables, for e.g. years of credit history. What is the method to determine how many bins and what is the interval for each bin?
|
Suppose that I am conducting a questionnaire study that is trying to measure level of awareness of subjects about a programming language and find the relation of those level of awareness to working conditions and methods etc.
To improve my precision I decided to go with stratified sampling. If I have 1 criterion for st... |
Given two multivariate gaussian (say in 2D with mean $\mu$ as a 2D point and convariance marix $\Sigma$ as $2$x$2$ Matrix) $N_1(\mu_1,\Sigma_1)$ and $N_2(\mu_2,\Sigma_1)$, I would like to derive the pdf of $N_1+N_2$.
Can any one point me to the reference where i can find the pdf derivation of $N_1 + N_2$.
Thanks in ad... |
I'd like to model a set of processes. The processes in question are related to human-decision making, so the model will need a measure of input, processing, and then, finally, output.
Ideally, the model would be implemented in something like R (which I know quite well) or Python (which I know less well).
Questions:
W... |
Question on pairs()
I'd like to use pairs() to choose a functional form for modeling a set of data. I know that several of my independent and dependent variables are probably lognormally distributed, so I'd like to produce pairs() plots where some of my variables are plotted on log axes and some are not.
It seems like... |
I have a Machine Learning course this semester and the professor asked us to find a real-world problem and solve it by one of machine learning methods introduced in the class, as:
Decision Trees
Artificial Neural Networks
Support Vector Machines
Instance-based Learning (kNN, LWL)
Bayesian Networks
Reinforcement learni... |
I have a set of data that looks at the number of "hits" a specific program makes over the course of time. The data goes back to September 2010, and includes data up to March 2011, so the data points are monthly. What I want to see if the most recent data (March 2011) shows a statistically significant decrease in the ... |
I am trying to perform logistic regression with lasso. For the logistic regression part I am using PROC LOGISTIC but I am not sure how to do lasso with PROC LOGISTIC. I searched online and found that PROC GLMSELECT allows us to do lasso. But I am not sure how to do logistic regression with lasso using PROC GLMSELECT. ... |
Context: To recommend a minimum sample size when performing multivariate testing of a web page. The sample size would vary based on the number of factors being tested (e.g. A heading, and an image) and the number of variations of a factor (e.g. Two different headings, and three different images). The goal could be to... |
I've tough luck with the use of nls() in R for the following model
$$N_e = N_o\{1-exp[\frac{(d+bN_o)(T_h N_e - T)}{(1+c N_o)}]\}$$
where $b>0$, $c\geq 0$, $T_h>0$, and $T=72$.
This code
T <- 72
NLS.Fit3 <- nls(Ne~No*(1-exp((d+b*No)*(Th*Ne-T)/(1+c*No))), data = Data,
start = list(d = 0.01, b = 0.01, Th = 0... |
Could someone come up with R code to plot an ellipse from the eigenvalues and the eigenvectors of the following matrix
$$
\mathbf{A} = \left(
\begin{array} {cc}
2.2 & 0.4\\
0.4 & 2.8
\end{array} \right)
$$
|
The location and scale of a normally distributed data can be estimated by sampling the data then taking the mean of the sample means and standard deviations, respectively. For non-normal (heavy-tailed) data, is it correct to take the median of the sample medians and IQR/MAD, instead? That is, is it correct to use the m... |
This questions consists of two parts that are quite similar and concern conditional probability.
Firstly, I would like to confirm the calculation of the conditional probability when we know the value of a random variable. Let's assume that we have a conditional matrix which gives us the values for $P(D|A\&B)$ and that ... |
I'm trying to reduce a dimension of my dataset. Maybe reduce is not a good word. I need to sample some of my dimensions.
Setup
For example:
I have $M$ events (let's say $M \tilde{} 60$). They are ALL labeled.
I have $K$ trials/repetitions (let's say $K \tilde{} 10$ or more). $K$ different sets of $M$ events.
Therefor... |
In the log-log regression case,
$$\log(Y) = B_0 + B_1 \log(X) + U \>,$$
can you show $B_1$ is the elasticity of $Y$ with respect to $X$, i.e., that $E_{yx} = \frac{dY}{dX}(\frac{Y}{X})$?
|
I was actually looking at this problem on slide 12. I will write it here briefly:
Problem:
Unknown number of people arriving in a fixed time period and my goal is to maximize my probability of picking the best candidate
Assumptions:
Assume people arrive in interval [0,1] independently
May assume also uniformly
Can N... |
I have a matrix of 1000 observations and 50 variables each measured on a 5-point scale. These variables are organized into groups, but there aren't an equal number of variables in each group.
I'd like to calculate two types of correlations:
Correlation within groups of variables (among characteristics): some measure ... |
My question concerns the assumption of additivity for intraclass correlation. I shall first explain what I have done and then end with my questions.
I want to calculate inter-rater reliability using intra-class correlation so I can report an overall coefficient (as done in previous similar research), and perhaps replac... |
Is there any use for the quantity
$$
\int f(x)^2 dx
$$
in statistics or information theory? $f$ is a probability density.
|
What "fat-tailed distributions" $p(x)$, symmetric about zero, have the property
$$\newcommand{\e}{\mathbb{E}}\newcommand{\rd}{\mathrm{d}}
\e e^X = \int_{-\infty}^{\infty} e^x p(x) \rd x < \infty \> ?
$$
Context
I'm attempting to price financial options for $X$ without using the Black–Scholes formula. It is usually ea... |
This is probably demonstrating a fundamental lack of understanding of how partial correlations work.
I have 3 variables, x,y,z. When I control for z, the correlation between x and y increases over the correlation between x and y when z was not controlled for.
Does this make sense? I tend to think that when one controls... |
I have a problem where I need to calculate linear regression as samples come in. Is there a formula that I can use to get the exponentially weighted moving linear regression? Not sure if that's what you would call it though.
|
In a data frame, I would like to get the column's index by name. For example:
x <- data.frame(foo=c('a','b','c'),bar=c(4,5,6),quux=c(4,5,6))
I want to know the column index for "bar".
I came up with the following but it seems inelegant. Is there a more straightforward builtin that I am missing?
seq(1,length(names(x)... |
I have $n$ standard normal and independent random variables $X_i$ (In reality I have a large known number of them, but let's just say I have $n$). In my experiment I want to on average get exactly 3 random variables $X_i$ under a threshold $c$. To get that, I can compute $c$ having that property easily, because the ave... |
In the one-dimensional case, if $X$ is $\mathcal{N}(\mu,\sigma^2)$, then $Y =\alpha X + \beta $ is $\mathcal{N}(\alpha \mu + \beta,\alpha^2\sigma^2)$ . We can prove this using the cumulative distribution function of of $Y$
$F_Y(a) = P\{Y \leq a\} = P\{\alpha X + \beta \leq a\} = P\{X \leq (a-\beta)/\alpha\}$.
Substitut... |
For a Dataset $D$, we have gold standard centroids say $c_1, c_2, \cdots, c_n$. Now if we run k-means algorithm on $D$ with input $n$, we get k-means centroid $k_1, k_2, \cdots, k_n$.
I just wanted to know, is there any algorithm/heuristic to match the centroids between $k_i$ and $c_j$ where $i, j= 1, \cdots, n$ (One t... |
I need to generate cross variograms of images using moving windows. For that I use the following equation:
$$
\gamma_{jk}(h)=\frac{1}{2n(h)}\sum_{i=1}^{n(h)}\Big\{\big[dn_j(x_i)-dn_j(x_i+h)\big]\cdot\big[dn_k(x_i)-dn_k(x_i+h)\big]\Big\}
$$
The first part stands for one band(j) and next part of band k. To illustrate ... |
I was wrestling with stationarity in my head for a while... Is this how you think about it? Any comments or further thoughts will be appreciated.
Stationary process is the one which
generates time-series values such that
distribution mean and variance is kept
constant. Strictly speaking, this is
known as weak ... |
In An Empirical Comparison of Supervised Learning Algorithms (ICML 2006) the authors (Rich Caruana and Alexandru Niculescu-Mizil) evaluated several classification algorithms (SVMs, ANN, KNN, Random Forests, Decision Trees, etc.), and reported that calibrated boosted trees ranked as the best learning algorithm overall a... |
I am new to evolutionary algorithm. I have studied Covariance Matrix Adaptation Evolution Strategy. I am not good at statistics. So could you please explain me in simple language (I mean not too many equations)
What is CMA-ES?
How does it work?
Why is it superior to other strategies?
|
I have a multi-class dataset like the following (a,b,c,d are features and e is the class (it can be 0,1 and 2)).
a b c d e
1 1 1 2 2 1
2 1 2 4 2 0
3 1 2 4 2 0
4 2 2 2 2 0
5 2 1 2 2 2
I am trying to use mlogit package in order to see which column is more important but I am having a difficulty to understan... |
This is probably a simple question.
I'm studying events which have N outcomes, of which exactly one is correct. N is very large, more than a billion (and is known). There are many possible events, some of which are tested multiple times.
I would like to test the following model: a given event is tested correctly with... |
I have a dataset with between 10,000 and 100,000 feature values. The number of datapoints is between 1,000 and 10,000. I want to perform a LASSO on this dataset but can't really find any good software to do so. Does anyone have any suggestions?
|
Context:
I am trying to analyze an experiment on plant community response to two treatments. Here’s a simplified description of the experiment, there are a few extra complications in reality.
Treatments were applied to small patches of ground arranged in blocks with a mix of naturally occurring plant species present... |
I'm compiling a survey that will have several questions which would lend to the creation of an index of a main dependent variable (level of engagement in sucession planning). The questions will involve topics like:
PROCESS: linking strategic planning to succession planning, identifying critical positions that need to... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.