similar to: Logistic Regression

Is there anyway to perform a query from within a validate function? I need to verify that the sum of several rows does not exceed a certain value eg: class Entry < ActiveRecord::Base belongs_to :day belongs_to :project def validate totalhours = hours samedayentries = self.find_by_day_id(day_id) samedayentries.each do

I would like to have a date control on a page and I would like a behavior similar to what you get using date_select with the :include_blank => true option where the first value in the dropdown is "- Month -", "- Day -", or "- Year -" rather than a blank value for the respective month, day, and year select fields. I took a look at the ruby source for

?Hola, Es más fácil que todo eso... Es que en tu fichero de entrada, la segunda fila son las unidades de las variables que tienes en la primera fila, pero "R" al leerlas las considera como un string que altera la clase de toda la columna cuando ésta es numérica. Simplemente eliminando esa segunda fila, las columnas acaban teniendo la clase que deben..

Hi. I'm analysing some fish biological traits with a gam in mgcv. After several tries, I got this model log(tle) = sexcolor + s(doy, bs = "cc", by = sexcolor) +log(tl) sexcolor is a factor with 4 levels doy is "day of year", which is modeled as a smoother tl is "total length of the fish" The summary of this models is (only parametric coefficientes): Parametric

Dear all, I am using the nlsLM function to fit a Lorentzian function to my experimental data. The LM algorithm should allow to specify limits, but the upper limit appears not to work as expected in my code. The parameter 'w', which is peak width at half maximuim always hits the upper limit if the limit is specified. I would expect the value to be in-between the upper and lower limit with