search for: variables_

Dear r-developers: I am struggling with some fundamental aspects of model.frame(). Conceptually, I think of a flow from data -> model.frame() -> model.matrix; the data contain _input variables_, while model.matrix contains _predictor variables_: data have been transformed, splines and polynomials have been expanded into their corresponding multi-dimensional bases, and factors have been expanded into appropriate sets of dummy variables depending on their contrasts. I originally thought o...

All, I''m wanting to initialize an ActiveRecord object. I understand that there is a method called after_initialize that appears to get called right after the ActiveRecord object is instantiated. Is after_initialize a Ruby thing or a Rails thing? Where is after_initialize documented? Can I pass parameters to it? If so, how? I want to initialize the "belongs_to" attribute of

Hi, I have the precision values of a system on two different data sets. The snippets of these results are as shown: sample1: (total 194 samples) 0.6000000238 0.8000000119 0.6000000238 0.2000000030 0.6000000238 ... ... sample2: (total 188 samples) 0.80000001 0.20000000 0.80000001 0.00000000 0.80000001 0.40000001 ... ... I want to check if these results are statistically significant? Intuitively,