search for: 2c260a95

Hello, I've had no luck finding an R package that has the ability to estimate a Tobit model allowing for heteroskedasticity (multiplicative, for example). Am I missing something in survReg? Is there another package that I'm unaware of? Is there an add-on package that will test for heteroskedasticity? Thanks for your help. Cheers, Alan Spearot -- Alan Spearot Department of Economics

Hello, I would like to inlude the Q-Q plot by "qqmath" into a panel with other plots, say, using par(mfrow=c(1,2)). How can this be done given that "qqmath" refreshes the plotting window and there seems to be no series coming out of it? Thanks Serguei [[alternative HTML version deleted]]

Hi, I'm trying to aggregate date values using the aggregate function. For example: aggregate(data,by=list(weekdays(LM),months(LM)),FUN=length) I would also like to aggregate by year but there seems to be no years() function. Should there be one? Is there any alternative choice? Also, a hours() function would be great. Any tip on this? Thanks in advance! S?rgio Nunes

...~~~~~~~~~~~~~~~~~~~~~~~~~~~ Laboratorio de Biolog?a de Organismos --- Centro de Ecolog?a Instituto Venezolano de Investigaciones Cient?ficas (IVIC) Apdo. 21827, Caracas 1020-A Rep?blica Bolivariana de Venezuela Tel: (+58-212) 504-1452 Fax: (+58-212) 504-1088 email: jferrer at ivic.ve clave-gpg: 2C260A95

...~~~~~~~~~~~~~~~~~~~~~~~~~~~ Laboratorio de Biolog?a de Organismos --- Centro de Ecolog?a Instituto Venezolano de Investigaciones Cient?ficas (IVIC) Apdo. 21827, Caracas 1020-A Rep?blica Bolivariana de Venezuela Tel: (+58-212) 504-1452 Fax: (+58-212) 504-1088 email: jferrer at ivic.ve clave-gpg: 2C260A95

Hi there, I'm writing a function that calculates the probability of different outcomes of dice rolls (e.g., the sum of the highest three rolls of five six-sided dice). I'm using the "combinations" function from the "gtools" package, which is great: it gives me a matrix with all of the possible combinations (with repetitions allowed). Now I want to count the number