-epclust = function(data=NULL, con=NULL, raw=FALSE, K, nbPerChunk, ...)
+#TODO: setRefClass... to avoid copy data !!
+#http://stackoverflow.com/questions/2603184/r-pass-by-reference
+
+#fields: data (can be NULL or provided by user), coeffs (will be computed
+#con can be a character string naming a file; see readLines()
+#data can be in DB format, on one column : TODO: guess (from header, or col. length...)
+epclust = function(data=NULL, con=NULL, raw=FALSE, K, nbPerChunk, ..., where_to_store_tmp_data, and how ?)
+#options for tmp files: in RAM, on disk, on DB (can be distributed)