search for: obersv

Hi Im attempting to build a sample variogram for 300 obersvations of longitudinal data. So what I need to do is compute the half squared differences between pairs of residuals (for instance if a subject has 4 obersvations, this is 4 choose 2 paird differences) for each subject. Also, then I need the corresponding time differences within each individual. S...

..., I'm looking for how can I input a linear model with an arma model,like log(y) = 8.95756 + 0.0346414^t - 0.1*t^2 + ut ut=-0.296ut-1+at-0.68at-1 where log(y) is qudratic function ,for the time series trend, and get then get the residuals from the first function. " obersvations value - the fit value = ut" and fit an ARIMA(1,1,1) model for ut. anyway,how can I combine this two models together as a group ? my purpose is to to use this mixed model forecast 'y' can you help me? I will very appreciate it. ___________________________...

Hi everyone! I'm new to R, and I'm stuck on a problem I don't know how to approach. I have calculated a regression in the form of M ~ D + O + S, and I would like to take this regression and test it with other samples, 5 at a time(5 meaning 5 set, each consisting M, D, O, and S of a specific date). I assume I'll need a for loop. Right now, My data of M, D, O, and S are all stored in

Hi all Does anyone know if it is possible when plotting a line or scatter plot, to selectively color the data points based on the data value? i.e. if plotting say the percentage change in stock price movements, to color +ve points in green and -ve points in red? And extending this to a user-defined range of colors based on the quartile of the data points? Thanks Rory Rory Winston RBS Global