# Tagged Questions

Techniques for analyzing the relationship between one (or more) "dependent" variables and "independent" variables.

0answers
21 views

### How can i find code( matlab, vb, c++) for running fuzzy regression?

I am new in fuzzy regression, i knew about its theory but have problems in running it in matlab or other programs. I will be so helpful if someone helps me in finding codes for fuzzy regression.
2answers
17 views

### Calculate the tendency of a set of samples

I develop an application in which i constantly get samples of heart pulse. I defined an interval of t seconds. In each t seconds I have n samples. In every interval, I want to calculate the ...
1answer
82 views

### How to compare two regression slopes for one predictor on two different outcomes?

I need to compare two regression slopes where: y ~ a + b1 x y ~ a + b2 x How can I compare b1 and b2? Or in the language of my specific example in rodents, I ...
0answers
21 views

### Breakpoint for bivariate data

The breakpoint(s) estimation approach implemented in the strucchange package (Zeilei & al) seems to work very well (based on my little experience with this package on real case studies). Is ...
1answer
36 views

### First difference or log first difference?

I am evaluating the effect of covariances between series on returns. That is I run the following regression: $$r_t = \beta_0 + \beta_1\text{Cov}(Y_t,r_t) + ...$$ I have conducted my analysis with ...
0answers
18 views

### R module for creating plots of prototypical individuals from fitted models?

In order to help interpret fitted models — especially those with interaction terms and non-linear components — I've found it useful to plot predicted values of a dependent variables for what we might ...
0answers
13 views

### Addressing multicollinearity with key driver analysis

I am trying to determine the key drivers from a series of 30 Independent Variables (IVs) (attributes rated on 10 pt scale) on 3 Dependent Variables (DVs) (i.e. purchase intent). The 30 IVs are pretty ...
1answer
26 views

### Conditional expected value from a regression model using ordinary least squares

I have a query regarding part (a) of the following question. I cannot figure out how to calculate the conditional expected value of collections for the month of Easter. Is it not possible to calculate ...
1answer
45 views

### Can I use a regression model with ANOVA significance greater than 0.05?

I have a multiple regression using SPSS. The significance of my model in the ANOVA table is p=0.174 which is >0.05. what does this mean for my model? Can I still use it and proceed in the ...
2answers
70 views

### How to interpret the output of the summary method for an lm object in R? [duplicate]

I am using sample algae data to understand data mining a bit more. I have used the following commands: ...
1answer
28 views

### Do you always measure reliability through the Cronbach's alpha coefficient? Or is there another way? (multiple linear regression)

I started doing a quantitative research for my thesis without any previous SPSS or proper statistic experience, and the first thing my professor told us in the spss workshop is that you start by ...
1answer
22 views

### Heckman's two stage: multiple selection models

If a sample is likely to be self-selected on multiple selection criteria, does it make sense to include Inverse Mill's ratios for multiple selection models in the same second stage OLS model?
1answer
43 views

### How to calculate confidence intervals of $1/\sqrt{x}$-transformed data after running a mixed linear regression in stata?

I have run a series of mixed linear regressions in Stata, some with inverse-square-root ($1/\sqrt{x}$) transformations and others with square root ($\sqrt{x}$) transformations. How do I calculate ...
0answers
26 views

### Performing Linear Regression on Rolling Averaged Data

I have multiple years of daily aggregated data for which I want to conduct a multi-variable linear regression. Auto correlation is high with one particular variable included and there is a strong ...
1answer
46 views

### Linear Regression with a Dependent Variable that is a Ratio

I'm doing linear regressions where the dependent variable is a ratio that can range from 0.01 to 100. Is it ok to take the log of the dependent variable and the regression on that? I'm matching the ...
0answers
23 views

### Regret in the linear regression setting

I've seen the concept of regret apply mostly to online learning problems, but while going through the definition it does seem that is not bounded to this setting. I'm trying to come with a simple ...
1answer
96 views

### Random forest assumptions

I am kind of new to random forest so I am still struggling with some basic concepts. In linear regression, we assume independent observations, constant variance… What are the basic ...
1answer
50 views

### Logistic regression: controlling variables not significant, what should I conclude/further test? [closed]

I ran annual logisitic regression on time-series datas. The most important independant variable have coefficient that are significant in a lot of years, that's a relief. But the "controlling ...
0answers
33 views

### How to build a model where variance depends on covariate?

I have what I believe is a very simple problem for anyone used to modelling with unequal variances (which I am unfortunately not). I have a dependent variable "totrich" which I want to model as a ...
0answers
8 views

### Error function of noisy input and target variables

Why is the sum of squares error function of noisy input and noisy target variables very similar to the error function for only noisy input? This is the relevant part in Bishop's book: Another ...
2answers
185 views

### How are regression, the t-test, and the ANOVA all versions of the general linear model?

How are they all versions of the same basic statistical method?
0answers
25 views

### Appropriate method for supervised learning of small data set with few variables

What method exc. for regression can be used in order to get y=f(x1,x2) on a training set of 800 to 2000 samples? y is a whole number <0,15>, x1,x2 are real <0,40>? I'm interested in prediction ...
1answer
33 views

### Weighted multiple regression in R with prespecified weights

I would like to run a regression of the following form: Y ~ B1*predictor1 + B2*predictor2 + B3*predictor3 I would like to specify ...
1answer
39 views

### Basic questions concerning the interpretation of results from summary(lm(…~…)) in R [duplicate]

set.seed(11) a = runif (12) b = rep(c(1,2,3),4) summary(lm(a~b))$coeff summary(lm(a~b-1))$coeff What does a p.value for the intercept means ? What differences ...
2answers
70 views

### Does the intercept count as a parameter for the n/parameters sample size rule for multiple regression?

When estimating parameters, I know the general rule of thumb is n/parameters should be >10. Does the intercept in a model count as one of the estimated parameters in this "rule"? For example, if I ...
1answer
48 views

### R Forward and backward Selection

I have a data set with large number of attributes some are not relevant and some are relevant for the regression model. My approach was to do forward and backward selection to identify a starting ...
0answers
19 views

### Changing prior for a regression model

I have a regression model trained on a particular output distribution (for example N(0, 1)). I now have to do a prediction on a test set, with a caveat that I know that the distribution of the test ...
0answers
19 views

### Strategy for building best fit multiple regression model with time lagged variables

I am building a multiple regression model - wrapped in a function - with one dependent variable and a dozen independent variables. The reason why I am building a function is that I need to do this ...
0answers
33 views

### OLS standard error log log regression

I am estimating the following Power Law relationship: $$\ln(\text{Rank}) = \text{constant} + \alpha \ln(\text{Size})$$ where $\text{Rank}$ is $1,~2,~3,~...,~n$, and $\text{Size}$ is the raw value. ...
1answer
47 views

### How many observations are enough to perform linear regression with fixed effects

I am new to econometrics. I am studying earnings management in banks during the financial subprime crisis. I manage to collect data from 23 banks from 2005 to 2010. Few years of them are missing but ...
1answer
89 views
+50

### What does the residual higher level variance tell me?

I have a multilevel logistic regression model predicting the probability of item nonresponse, where the random intercept variance at country level takes on the following distribution for the different ...
3answers
65 views

### Which glm algorithm to use when predictors are numerical as well as categorical?

I just need a direction on which regression algorithm (preferably glm or similar) algorithm to use when the predictor variables are a mix of numerical and categorical variables. The output is ...
1answer
73 views

### Multiple Choice on Linear Regression

1. Which one is NOT a linear regression models? Please give a 1-2 sentences brief explanation to your choice. (a) $y_i = β_0 +\exp(β_1x_i)+E_i, i = 1, 2, \ldots, n$ (b) \$y_i = β_0 + β_1x_i + β_2 ...
0answers
66 views

### Universal Approximation Theorem — Neural Networks

I have posted this question elsewhere--MSE-Meta, MSE, TCS, MetaOptimize. Previously, no one had given a solution. But now, here is a really excellent and comprehensive answer. Universal approximation ...
1answer
52 views

### Model Building: Missing Data or Large Gap between data points

I am currently trying to build a model using a data set that has large gap between data points. When I look for the correlation I clearly see a negative regression line. But I am worried about the gap ...
1answer
66 views

### normality distribution

I have a problem with normality test. In order to make sure that I can use parametric test, I need to make sure that my residual distribution is normal. However, when I refer to the value of skewness ...
1answer
45 views

### Hold-one-out linear regression : a shortcut?

For a series of observations $(\vec{x}_i, y_i), i = 1 \cdots N$ from the linear model $Y = \beta^T X + \epsilon$, the least squares estimate of $\beta$ is: \$\hat{\beta} = (\mathbf{X}^T ...
0answers
31 views

### Brant test in R

In testing the parallell regression assumption in ordinal logistic regression I find there are several approaches. I've used both the graphical approach (as detailed in Harrell´s book) and the ...
1answer
39 views

### Polynomial regression using scikit-learn

I am trying to use scikit-learn for polynomial regression. From what I read polynomial regression is a special case of linear regression. I was hopping that maybe one of scikit's generalized linear ...
1answer
67 views

### Is $R^2$ value valid for insignificant OLS regression model?

I am interested in stating that ___ % of the variance in Y is explained uniquely by $X_1$ and ___ % is explained uniquely by $X_2$. Is there some way to obtain this from a multiple regression ...
1answer
82 views

### How to handle Regression data thats not linear

I'm new to stats and am using Python 2.7 to fit a regression model (Random Forest). When I plot the percentile plot of the prices before and after a log ...
2answers
99 views

### Estimating $b_1 x_1+b_2 x_2$ instead of $b_1 x_1+b_2 x_2+b_3x_3$

I have a theoretical economic model which is as follows, $$y = a + b_1x_1 + b_2x_2 + b_3x_3 + u$$ So theory says that there are $x_1$, $x_2$ and $x_3$ factors to estimate $y$. Now I have the real ...
0answers
20 views

### Testing for structural break on included variables under heteroscedasticity

I am doing an analysis on how energy ratings affects the prices in the housing market. My data series ranges from 2003 to 2013, and to account for fluctuations in the sales price over time, I use ...
2answers
67 views

### Help with Anova of categorical and continuous variable in R and SPSS output

I am having some trouble running an Anova on categorical variables in R and matching SPSS output. What I need to do is run an anova on the dataset below (its a made up data set). But, I need to know ...
0answers
44 views

### When to Log/Exp your Variables when performing Linear Regression?

I'm doing regression using Random Forests for predicting prices based on several attributes. Code is written in Python using Scikit-learn. How do you decide whether you should transform your ...
0answers
15 views

### Non-integer dependent variable in negative binomial models

I have non-nested count data that I've interpolated from one area to another based on the proportion of the area that lays in each. This is ZIP codes to counties, so most nest cleanly, with a few ...
0answers
16 views

### Proc GENMOD estimate statement with 2 continuous variables?

I'm testing an ordinal scale measuring dyskinesia (range=0-4) via proc genmod, with the independent variables in the model being Drug1 and Drug2. Both of these variables are continuous. I want to ...
0answers
31 views

### Ratios in Regression, aka Questions on Kronmal

Recently, randomly browsing questions triggered a memory of on off-hand comment from one of my professors a few years back warning about the usage of ratios in regression models. So I started reading ...
1answer
62 views

### Calculating the linear model with R

I need to calculate the linear model in R, i did the following: summary(model) But what if I wanted to calculate only the first point? A bit stuck with this one... Many thanks! Here is the code ...
1answer
45 views

### Mean squared error definition

I'm currently working through (part of) a textbook on non-parametric regression techniques. Regarding the choice of smoothing parameter the book starts out explaining the MSE which is defined as: ...
{"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 20, "mathjax_display_tex": 3, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "github"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "english_confidence": 0.8969458341598511, "perplexity_flag": "middle"}