# regression's questions - Chinese 1answer

16.262 regression questions.

### 3 How to calculate p-value for multivariate linear regression

Software packages that calculate regressions sometimes also return p-values. I want to understand how to calculate this p-value by hand. Here's what I think I understand: I want to calculate the ...

### Interpreting two multiple linear regression models

0 answers, 6 views regression linear
I fitted a multiple linear regression model which included 5 explanatory variables ("model 1"). After this I realised that maybe I was omiting several interesting variables so I fitted another model ...

### 2 Paired data comparison: regression or paired t-test?

3 answers, 41 views regression t-test paired-data
Question I always used a paired t-test or a wilcoxon signed rank test (of course depending on the dataset) to check whether two methods (on average) yielded the same results. After learning more about ...

### 1 Aggregating factors: dummy vs. relative frequency

I have a dataset that looks like this: ...

### Logistic regression with independent variable values less than 1

0 answers, 16 views regression logistic ratio odds
I have one independent variable which has values less than 1, and want to see how the odds of having a disease change when the independent variable increase by 0.1. I ran a binary logistic regression ...

### 1 Predictive model in R

I have the data of events occurring randomly. Variables include, Unique ID,type, Date of Event, End date etc. I have the dates of, when the event occurs for 6 years. I need to predict the next ...

### 3 Can I still use Linear Regression assumptions test on a linear model with a Polynomial variable

I have a multivariate linear model (y=x1+x2) which gives me the following results when using R's plot() function: I can clearly see that the Normality and ...

### 1 U shaped data in Simple linear regression

1 answers, 23 views regression data-transformation linear
I am working on an analysis of a simple linear regression and I don't know what to do. This is my graph: the p-value is <0.0001 but the data is clearly not linear and $R^2$ value is really small. ...

### What is meaning of high AIC value?

I have a query related AIC value. I am getting very high AIC values while selecting multiple regression model, ranging from 4300-4600. Is it possible to get such high AIC values?

### 1 k-fold cross validation of segmented regression

I am solving a MILP problem in my current master thesis and I got stuck with some issue. Originally, I had it a set of data points that I was using to build an OLS regression model of second order. ...

### How do you deal with missing column data for 98% of rows? [closed]

I have a case where I have only 2.7% of the rows having value for a particular column? What steps could I take to utilize it? Any specific methods? Also, any algorithms or techniques for utilizing ...

### 1 Censored regression methods for analyzing extreme end of a normally-distributed variable

1 answers, 15 views regression exponential censoring
I have a normally distributed continuous variable referring to an observed human behavior, and I'm interested in measuring or rather analyzing the extreme of this behavior, namely, the top 10% of the ...

### Likert-scale data as DV… curious as to which regression model to use

I have a 1-10 Likert scale as my DV and five variables as my IV. My IVs include both continuous and categorical variables. I am wondering which independent variables have a major effect on my ...

### 3 What are the relation and differences between time series and linear regression?

1 answers, 326 views regression time-series
What are the relation and differences between time series and linear regression? I have a strong grasp of linear regression, and a beginner's grasp on time series analysis; I know the Box-Jenkins ...

### 3 Autocorrelation and heteroskedasticity in time series data

I have several time series of two variables over the course of one year (approx. 2.5k observations). I hypothesize one variable (x) acts as a potential predictor for the other variable (y). I looked ...

### 1 Non-uniform density of observations

0 answers, 19 views regression multiple-regression
I would like to build a regression model to predict an outcome variable, y. Let ymin, ymax be the smallest and largest observed values of y in the dataset. Let ymean be the mean observed value. The ...

### 2 What modeling problem does ridge regression solve?

If your modeling problem is that you have too many features, a solution to this problem is LASSO regularization. By forcing some feature coefficients to be zero, you remove them, thus reducing the ...

### Fixed y and solve $x_i$ in regression

Suppose we have three explanatory variables like $x_1,x_2,x_3$ and three response variables like $y_1, y_2, y_3$, we know that y should be a function of x, such that  (y_1,y_2,y_3) = f(x_1,x_2,x_3) \$...

### 3 Logistic regression vs Random forest vs GBM: equal performance?

I'm trying to convince my boss that we should consider using machine learning in our field (oncology). We study brain tumours, roughly 90% die within a few years. I wanted to compare the performance ...

### 18 Assumptions of multiple regression: how is normality assumption different from constant variance assumption?

5 answers, 1.642 views regression multiple-regression assumptions
I read that these are the conditions for using the multiple regression model: the residuals of the model are nearly normal, the variability of the residuals is nearly constant the residuals are ...

### 2 Adjust for variable in mixed effects model

I've looked at prior posts as well as the lme4 documentation in R but can't seem to find a solution to my problem. I am trying to model how an intervention (tutoring), impacts examination pass rates ...

### Using GARCH and LDA

I'm working on a regression model using Latent Dirichlet Allocation (LDA). Using daily news data, I'm using a GARCH-model to see if different topics found using LDA indeed are significant in the ...

### Is there an equivalent to a linear model that uses the median as central descriptor for categories?

Since the median is often a better central descriptor of skewed distributions, I'd like to know if there is an equivalent method to a linear model for explaining variability of one variable through a ...

### 2 Linear combination of two non-independent random variables

I would like to check if the slope coefficients retrieved from two separate regression models are significantly different. Both models have the same independent variables. The dependent variable (DV) ...

### 10 Why are the Least-Squares and Maximum-Likelihood methods of regression not equivalent when the errors are not normally distributed?

Title says it all. I understand that the Least-Squares and Maximum-Likelihood will give the same result for regression coefficients if the model's errors are normally distributed. But, what happens if ...

### 1 Linear Regression - Cutting a Continuous Predictor into 2 Separate Continuous Predictors

0 answers, 18 views regression linear
I have a variable (call it V) that I want to create a linear model with. The problem is that I want to break up this continuous variable V into 2 continuous variables (such as V1 for V<0, and V2 ...