curve fitting

  1. E

    Linear modelling

    Hi, I need some help with a modeling query: I have fit 100,000 linear models: M ~ age + age^2, M is the frequency. I found 2,000 models were significant, but would like to narrow it down to find the most ‘extreme’ cases. Is this possible? Does anyone have any suggestions or any references...
  2. B

    4PL Non-Linear Regression, Transforming observed y values

    Good Afternoon, I'm currently teaching my self how to fit response curves, and have run into some trouble. I currently need assistance on utilizing proper methodologies to "massage" the observed y values. Is it wise to log transform the y values, knowing that this changes the vertical...
  3. S

    "Error in paste" when fitting a latent curve model using OpenMx

    Hi all, I am relatively new to R. I have been using it to estimate structural equation models using OpenMx. Now I am trying to fit a latent curve model using a script that I have used many times, but now I get an error which I cannot find a solution to! I don't know whether I should...
  4. L

    Should the standard error (SE) of the best-fit coefficients be propagated?

    Hi all, This is how I understand it. Please correct me if I’m wrong: When fitting models to experimental data the statistical software produces a set of best-fit coefficients and automatically calculates their respective ‘asymptotic’ standard error (SE). The SE for each coefficient describes...