# Search results

1. ### similarity between two random variables

There have two random variables, each of which is of five dimension. One random variable tracks the data collected from one device. The other random variable represents the data collected from another device. I would like to see whether these two devices are replaceable with each other by...
2. ### how to find interaction terms in regression modeling

Given a set of predictor variables, are there any ways to test interaction terms? If I test one by one, it will be impossible to do it?
3. ### regression models with mixed types of independent variables

I am working on building a forecasting model, the independent variables are grouped into three types: some variables are continuous; some variables are ordinal; while some variables are nominal. The dependent variable is continuous. Can the normal multiple regression model handle this kind of...
4. ### mixed predicator types for building logistic regression model

There has a data set, some predicator variables are of categorical types, such as X1={A, B,C}; X2={1, 2, 3}; and other predicator variables are of continuous types, such as X3 can be a real value between 0 and 100. If we want to build a logistic regression model based on these predicator...
5. ### Sampling from N data points based on a given probability distribution

I have N data points, and each data points is associated with a probability. The sum of the N probabilities equals to one. I need to sample these N data points based on the given probability vector. Are there any algorithms that can allow me to do this kind of sampling?
6. ### Finding specific terms in several files.

I have several documents, and would like to see which files contain a given term. How to do that in R?
7. ### the summary statistics for characterizing the differences between two data sets

I have two measurements for the same experiment. Right now, I want to compare how different are these two measurements. Are there any summary statistics that can be used to describe the differences? In addition, are there any graphical approaches to visualize these differences? Mesurement1...
8. ### Compute the intersection of two csv file

I have two csv files sharing some common columns. They are referred to as A.csv and B.csv. Right now, I need to generate two new files. C.csv is the intersection of A.csv and B.csv; D.csv consists of the remaining columns after subtracting C.csv from B.csv. Are there any approaches to do the...
9. ### question on complete confounding and partial confounding in multiple regression

While learning multiple regression, I once meet the concepts of “complete confounding” and “partial confounding” In the model, the response variable is referred to as Y. There have two predictor variables: X1 and X2. With respect to the complete confounding, the correlation between X1 and X2 is...
10. ### sampling issue for a data set with an embedded pattern

I have a large set of data sets. For instance, it has 30000 data points, which are identified as 1, 2, 3,…30000. For notational purposes, D(i) represents the data value for a point identified as i. These data points have the following localized pattern, For a given integer value k...
11. ### Regarding negative correlation and negative variance estimation result

In ANOVA, we sometimes talk about that variance estimation can get negative result when there is negative correlation. I do not understand what does the "negative correlation" refer to? Or which kind of relationship among data does "negative correlation" model? Moreover, how to understand...