[amelia] Amelia output extracted from output[[ ]] looks odd [WAT Issue #2]

RE: Amelia output extracted from output[[ ]] looks odd [WAT Issue #2] PROBLEM: After running Amelia to generate 5 imputed files, the output files extracted using output[[ ]] look odd.... BACKGROUND: Here is my command line to run Amelia: ******************* CONTROL PANEL ******************* impruns <- 5 tolX <- 0.0001 empriX <- 100 autopriX <- 0.05 resampleX <- 100 *************************** CONTROL PANEL ******************* imputed <- amelia(DATA8i, m = impruns , p2s = 2 , idvars = c(3,4,5) , ts = 1 , cs = 2 , polytime = NULL, startvals = 0 , tolerance = tolX , noms = nomIV8i , ords = ordIV8i , incheck = T , collect = F , outname = "DATA8imp", write.out = T , archive = T , keep.data = T , empri = empriX , autopri = autopriX , bounds = IVlims, max.resample = resampleX ) After a run I am able to extract output info from... imputed[[ ]] The user guide (p.27, under "Output") says. "...you can refer to any of the datasets by referencing output[[i]], where i is the number of the dataset you wish to reference. These datasets will be returned in the same format which you passed them...." However, the files imputed[[1]], imputed[[2]] are quite different from the original input file, and different from each other. -- The input file is a data frame (1044 x 487). with no header. -- Output files: imputed[[ 1]] 1044 x 2435 numeric; looks like imputed values NOTE: 2435 = 5 * 287... imputed[[ 2]] 1 x 1 "5" imputed[[ 3]] TRUE / FALSE imputed[[ 4]] 483 x 2415 numeric, does NOT look line imputed values NOTE: 483 = number of IV minus 4; Data set includes 3 identity variables, 1 time series var, 1 cross-section var imputed[[ 5]] 483 x 5 numeric, does NOT look line imputed values These output files raise the following comments/questions: (1) Contrary to the info in the user guide, the output files extracted from output[[i]] do not match the format of the input file. (2) Does whether or not the input file has a header row (variable names) affect how Amelia works? (This question may be an artifact of my lack of understanding about working with data frames... But if you read in the output csv file and compute nrow(file), the result is one less than the number of rows actually in the csv file. (3) Is the first output file [[1]] the 5 sets of imputed data? (4) I have no idea what the other files are... Are they for diagnostics? Thanks, Wayne SUBMITTED BY: Wayne A. Thornton Harvard Univ. thornton(a)fas.harvard.edu 781-492-3131 <http://1429236.signature1.mailinfo.com/confirm2.6/0000000B/0007074E/06024E0 0/21422241.jpg>