linear regression

  1. A

    Mixed effects modelling

    Hey all, Im building a linear mixed effects model of a variable, lets say the headway time maintained by drivers in car following situations. I want to use a training dataset to come up with a linear regression model and validate this model by running it through several sets of validation data...
  2. jpkelley

    Constrained linear regression in R

    Hi all, Using R, I'm running a linear regression for part of a function I'm writing to calculate survival rates from age distributions. My question for the purpose of this thread is following. Given the following sample data set: set.seed(100) fake.data <- data.frame(x=seq(1:20), y=rnorm(20...
  3. S

    Panel Data: Conducting N time-series regressions and averaging coefficients

    Hi, I stumbled upon a special regression method in a published paper (A+ journal) that I hadn't heard before. In dealing with a panel data set, the authors perform a time-series regression for each single entity. As they explain, "The reported coefficient values are averages of the...
  4. S

    Linear Regression output changes every time

    Hi everybody I'm performing a Linear Regression with SPSS in with one dependent variate and 11 independent ones (these are not my fixed factors, I analyzed them previously in a Mixed Model; these 11 IV are covariates in my experiment). I want to find out which of these IV explain the DP. So...
  5. B

    Yes its me again probably with another really easy question

    Thanks so much for the help on the last question. I promise I am not doing homework. I am really just trying to figure out how this stuff works. I am pretty sure that I am just not seeing something on this one too. Like the last one I did not deduce the mean. Simple Statistics...
  6. B

    I dont know why finding an intercept is so hard

    Thanks in advance to whoever helps =)! I am trying to find the intercept for a linear regression with 10 observations. Given: Sxy=120 Sxx=42 Sum of x=50 Sum of y=100 I found the slope it is 2.857. I have looked at all the formulas and decided that the means are what I really need...
  7. D

    Linear regression-Urgent help required

    I'm kind of freaking out as I have a presentation next week but there is a problem with my results that I have to present. I am doing linear regression looking at the effect that different foods have on BMI etc, however no matter WHAT I do, the r-squared value is working out ridiculously low...
  8. L

    Correlation and Linear Regression

    Hello! I am new to this forum and new to statistics and I am everything that the word "confused" encompasses. I am stuck on a homework question and cannot proceed until I figure it out. A sample of 88 Puget Sound butter clams' widths had mean 4.4 and standard deviation 1.8. Their lengths had...