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0answers
17 views

Multiple Variable Ranking

Before i start, i should mention i am pursuing my under-grad degree, and hence i have little/basic knowledge about machine learning and statistics. I've been meaning to make an application which ...
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0answers
27 views

Marginal pdf when variable´s domain is restricted by another variable

Given a joint pdf for 3 random variables (X1, X2, X3) I´ve applied a transformation (Y1, Y2, Y3) and found the joint pdf for the transformed variables. This joint pdf´s domain is 0 < Y1 < Y2 ...
2
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1answer
80 views

Nearly constant time series

I want to analyse temporal interactions of some time series by means of the Box-Jenkins approach to find out which time series are predictors of another one (with the help of prewhitening and ...
3
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0answers
91 views

Determine linear relationship between input and output with multiple input variables

Say that your input variables are in $\mathbb{R}^2$ with a univariate output variable. Say that you want to determine whether the output variable is a linear combination of the input variables. If ...
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0answers
24 views

Attribution Analysis for Multi-Variable Equation

I have a multi-variable equation in which I am trying to run an attribution analysis for the change from one period to another. For example: Initial Period X*Y+Z = 100 Where X=2 Y=40 Z=20 Second ...
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2answers
165 views

How to get from joint distribution F(x,y) to f(x,y) to calculate the marginal distribution of X?

I have this homework question I'm not 100% sure how to tackle. I have a random vector with joint distribution function F(x,y) and am asked to find the marginal distribution function. I think need ...
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3answers
3k views

Does adding more variables into a multivariable regression change coefficients of existing variables?

Say I have a multivariable (several independent variables) regression that consists of 3 variables. Each of those variables has a given coefficient. If I decide to introduce a 4th variable and rerun ...
-1
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1answer
256 views

Logarithmic regression of form $y=a+b \log(x_1)+c\log(x_2)$ using R [closed]

How can I fit a logarithmic regression equation of form $y=a+b (\log (x_1)) + c(\log(x_2))$ on a data set using R? Here the main concern is that data contain zeros multiple times, so R will give ...
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2answers
142 views

I need a model that can predict based on multiple variables. How do I get started?

I have a problem where I have to predict a variable X that is dependent on several other variables a,b,c,d... I have the data containing the values of these variables a,b,c,d.. and also X up to a ...
2
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1answer
213 views

What to do when there are too many variables?

I found that the probability of an event occurring is an algebraic function of all the probabilities that I want to find; $$P(v_1,v_2,v_3,...,v_n)=p_{collected}$$ For small $n$, it would be easy to ...
1
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0answers
158 views

References about univariable vs multivariable variable selection

Suppose I have variables $X_j$, $j=1,\ldots,p$, some of which are correlated, and some continuous output $y$. I want to rank the variables by importance. One way is to do an association test of each ...
2
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2answers
1k views

Multiple dependent variables in factorial design

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 ...
4
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1answer
3k views

Readdressing the semantics of multivariate and multivariable analysis

There was a post once upon time dealing with the differences of multivariable and multivariate regression. I have seen the relevant post here. However I am having this debate with a colleague and ...
2
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2answers
142 views

Visualizing a 5x5x5 data set

I'm trying to visualize a matrix of 3 datasets.* For the sake of example, let's say I have a list of hats, coats and shoes, and I want to display a 2D grid/visualization of each possible combination. ...
7
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4answers
934 views

What are the software limitations in all possible subsets selection in regression?

If I have a dependent variable and $N$ predictor variables and wanted my stats software to examine all the possible models, there would be $2^N$ possible resulting equations. I am curious to find ...
3
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1answer
237 views

Estimating probability distribution function of a data stream

I have a very large number of observations. Observations arrive sequentially. Each observation is an $n$-dimensional vector (with $n \ge 100$), is independent from the others and is drawn from the ...
6
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1answer
189 views

From Marginal Exp-Norm Distributions to What Conditionals and Joint?

I have (trivariate: multivariate with three variables) data that appears to be good empirical and reasonable theoretical fit for a (univariate) convolution of an exponential and a normal distribution ...
9
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1answer
803 views

Finding marginal densities of $f (x,y) = c \sqrt{1 - x^2 - y^2}, x^2 + y^2 \leq 1$

As the title says, I'm looking for the marginal densities of $$f (x,y) = c \sqrt{1 - x^2 - y^2}, x^2 + y^2 \leq 1.$$ So far I have found $c$ to be $\frac{3}{2 \pi}$. I figured that out through ...
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2answers
872 views

Computing best subset of predictors for linear regression

For the selection of predictors in multivariate linear regression with $p$ suitable predictors, what methods are available to find an 'optimal' subset of the predictors without explicitly testing all ...
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7answers
950 views

Is there an accepted definition for the median of a sample on the plane, or higher ordered spaces?

If so, what? If not, why not? For a sample on the line, the median minimizes the total absolute deviation. It would seem natural to extend the definition to R2, etc., but I've never seen it. But ...
4
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2answers
636 views

Orthogonal parametrization

In general inference, why orthogonal parameters are useful, and why is it worth trying to find a new parametrization that makes the parameters orthogonal ? I have seen some textbook examples, not so ...
2
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1answer
545 views

Dataset for multi class perceptron

I am developing a multi-class perceptron algorithm and was wondering if there are any datasets that could be used to test a multi-class perceptron? - A dataset where the classes are linearly separable ...
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13answers
7k views

What is the best way to identify outliers in multivariate data?

Suppose I have a large set of multivariate data with at least three variables. How can I find the outliers? Pairwise scatterplots won't work as it is possible for an outlier to exist in 3 dimensions ...
2
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1answer
218 views

Multivariate Interpolation Approaches

Is there a good, modern treatment covering the various methods of multivariate interpolation, including which methodologies are typically best for particular types of problems? I'm interested in a ...