search for: raffaello

Dear R help, Suppose I have a dataframe with three columns named p, v and C. Here C is a function of both p and v. I can plot the surface C(p,v) using the package lattice using the function wireframe. Now if I have another dataframe - with 2 columns named p_ind and v_ind and pind is a function of v_ind. I would like to overlay the plot of the curve p_ind, v_ind and C(p_ind, v_ind) onto my

Dear All, I know this may be a trivial question. In the past I have used glm to make logistic regressions on data. The output creates an object with the results of the logistic regression. This object can then be used to make predictions. Great. I have a different problem. I need to make predictions from a logistic regression taken from a paper. Thus I need to (by hand) enter the reported odds

Dear users, I can access an database oracle database using sql developer. This was done by importing an xml file that contains the login details - username, password and specifies that it uses the KERBEROS_AUTHENTICATION. I'm trying to connect R - so that it can access this database - do sql queries and convert the resulting tables into dataframes. I am a novice in SQL and database access

Dear R-Users, I am learning how to use the package VGAM to do multinomial regressions. I have worked through the example provided by UCLA stats group: http://www.ats.ucla.edu/stat/r/dae/mlogit.htm However - what I would like to learn is how to use the constraint option. So in the example given in the link i would like to introduce a constraint that does not allow individuals of age less than

Please, could you tell me how to enter a mixed or a purely conditional multinomial logit model in NNET. I know how to do a multinomial logit in NNET but I don't know how to do conditional or mixed models using this package. I do know how to do this with VGAM - but would like to compare my results to those obtained by NNET. Thanks. Raffaele.

Dear Help, I am using the library RODBC to export data into an excel file with different sheets. Here is the code: library(RODBC) save2excel <- function(x, t.name,channel) { sqlSave(channel, x, tablename = t.name, rownames = FALSE) } ## Write Parameters to Excel channel <- odbcConnectExcel(paste(data.dir,"Calibrated_Parameters_Full_Set",".xls",sep=""),