box-cox

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    Mixed ANOVA - Can We Standardize After Box-Cox Transformed Values

    Background: In a mixed ANOVA (2 timepoints, 3 interventiongroups, so 2x3 factorial ANOVA), the homogeneity of the residual variance was violated as indicated by significant Levene test, for the post-intervention measurement timepoint (T2) As far as I understand it, this prohibits any further...
  2. D

    calculating Z for Box-Cox

    Hello, I'm a bit rusty with my maths and trying to recall how to calculate Z for a box-cox distribution (LMS). For a given LMS how do I get the Z index for a given probability.
  3. S

    Box Cox Transformation on time series

    Hi, I want to apply box cox transformation on my time series. I was just wondering can I apply the transformation on any time series or do i have to fix up the time series prior to. I have a non stationary time series with deterministic trends.. would i have to make it stationary first or no...
  4. J

    Linear Mixed Effects and interpreting transformations

    Hi, I'm running a hierarchical linear mixed effects model in R (subject is nested in dyad). My dependent variable is a continuous variable. When I run the model I do not meet the assumption of homogeneity. A log transformation on the dependent variable does not work. However, when I use a box...
  5. G

    Finding lambda for Box-Cox transformations for non-statisticians

    I've learned that statisticians are not to be trifled with, because every time I read anything about selecting lambda with the slopes of log-likelihoods and whatnot, it feels like I'm trying to grasp oil. That's on fire. That's why I fudge it and use the lambda where the resulting skew of the...
  6. H

    -->(BOX-COX) Transformation breaks down for large (positive) coefficient values <--

    Hi, I have done a box-cox transformation of my response variable, using the following formula: (Y^lambda - 1)/lambda Previously, I have got some excellent help in understanding the way interpretation works for different levels of Y (q1,median,q3). My formula for inverse transformation is...