Fix package, ok for R CMD check - ongoing debug for main function
[epclust.git] / epclust / R / main.R
index eded952..b09e934 100644 (file)
-#' @include defaults.R
-
-#' @title Cluster power curves with PAM in parallel
+#' CLAWS: CLustering with wAvelets and Wer distanceS
 #'
-#' @description Groups electricity power curves (or any series of similar nature) by applying PAM
-#' algorithm in parallel to chunks of size \code{nb_series_per_chunk}
+#' Groups electricity power curves (or any series of similar nature) by applying PAM
+#' algorithm in parallel to chunks of size \code{nb_series_per_chunk}. Input series
+#' must be sampled on the same time grid, no missing values.
 #'
-#' @param data Access to the data, which can be of one of the three following types:
-#' \itemize{
-#'   \item data.frame: each line contains its ID in the first cell, and all values after
-#'   \item connection: any R connection object (e.g. a file) providing lines as described above
-#'   \item function: a custom way to retrieve the curves; it has two arguments: the start index
-#'     (start) and number of curves (n); see example in package vignette.
-#' }
-#' @param K Number of clusters
-#' @param nb_series_per_chunk (Maximum) number of series in each group
+#' @param getSeries Access to the (time-)series, which can be of one of the three
+#'   following types:
+#'   \itemize{
+#'     \item matrix: each line contains all the values for one time-serie, ordered by time
+#'     \item connection: any R connection object (e.g. a file) providing lines as described above
+#'     \item function: a custom way to retrieve the curves; it has only one argument:
+#'       the indices of the series to be retrieved. See examples
+#'   }
+#' @inheritParams clustering
+#' @param K1 Number of super-consumers to be found after stage 1 (K1 << N)
+#' @param K2 Number of clusters to be found after stage 2 (K2 << K1)
+#' @param wf Wavelet transform filter; see ?wavelets::wt.filter
+#' @param ctype Type of contribution: "relative" or "absolute" (or any prefix)
+#' @param WER "end" to apply stage 2 after stage 1 has fully iterated, or "mix" to apply stage 2
+#'   at the end of each task
+#' @param random TRUE (default) for random chunks repartition
+#' @param ntasks Number of tasks (parallel iterations to obtain K1 medoids); default: 1.
+#'   Note: ntasks << N, so that N is "roughly divisible" by N (number of series)
+#' @param ncores_tasks "MPI" number of parallel tasks (1 to disable: sequential tasks)
+#' @param ncores_clust "OpenMP" number of parallel clusterings in one task
+#' @param nb_series_per_chunk (~Maximum) number of series in each group, inside a task
 #' @param min_series_per_chunk Minimum number of series in each group
-#' @param writeTmp Function to write temporary wavelets coefficients (+ identifiers);
-#'   see defaults in defaults.R
-#' @param readTmp Function to read temporary wavelets coefficients (see defaults.R)
-#' @param wf Wavelet transform filter; see ?wt.filter. Default: haar
-#' @param WER "end" to apply stage 2 after stage 1 has iterated and finished, or "mix"
-#'   to apply it after every stage 1
-#' @param ncores number of parallel processes; if NULL, use parallel::detectCores()
+#' @param sep Separator in CSV input file (if any provided)
+#' @param nbytes Number of bytes to serialize a floating-point number; 4 or 8
+#' @param endian Endianness to use for (de)serialization. Use "little" or "big" for portability
+#' @param verbose Level of verbosity (0/FALSE for nothing or 1/TRUE for all; devel stage)
+#'
+#' @return A matrix of the final medoids curves (K2) in rows
+#'
+#' @examples
+#' \dontrun{
+#' # WER distances computations are a bit too long for CRAN (for now)
+#'
+#' # Random series around cos(x,2x,3x)/sin(x,2x,3x)
+#' x = seq(0,500,0.05)
+#' L = length(x) #10001
+#' ref_series = matrix( c(cos(x), cos(2*x), cos(3*x), sin(x), sin(2*x), sin(3*x)),
+#'   byrow=TRUE, ncol=L )
+#' library(wmtsa)
+#' series = do.call( rbind, lapply( 1:6, function(i)
+#'   do.call(rbind, wmtsa::wavBootstrap(ref_series[i,], n.realization=400)) ) )
+#' #dim(series) #c(2400,10001)
+#' medoids_ascii = claws(series, K1=60, K2=6, "d8", "rel", nb_series_per_chunk=500)
 #'
-#' @return A data.frame of the final medoids curves (identifiers + values)
-epclust = function(data, K, nb_series_per_chunk, min_series_per_chunk=10*K,
-       writeTmp=defaultWriteTmp, readTmp=defaultReadTmp, wf="haar", WER="end", ncores=NULL)
+#' # Same example, from CSV file
+#' csv_file = "/tmp/epclust_series.csv"
+#' write.table(series, csv_file, sep=",", row.names=FALSE, col.names=FALSE)
+#' medoids_csv = claws(csv_file, K1=60, K2=6, "d8", "rel", nb_series_per_chunk=500)
+#'
+#' # Same example, from binary file
+#' bin_file = "/tmp/epclust_series.bin"
+#' nbytes = 8
+#' endian = "little"
+#' epclust::binarize(csv_file, bin_file, 500, nbytes, endian)
+#' getSeries = function(indices) getDataInFile(indices, bin_file, nbytes, endian)
+#' medoids_bin = claws(getSeries, K1=60, K2=6, "d8", "rel", nb_series_per_chunk=500)
+#' unlink(csv_file)
+#' unlink(bin_file)
+#'
+#' # Same example, from SQLite database
+#' library(DBI)
+#' series_db <- dbConnect(RSQLite::SQLite(), "file::memory:")
+#' # Prepare data.frame in DB-format
+#' n = nrow(series)
+#' time_values = data.frame(
+#'   id = rep(1:n,each=L),
+#'   time = rep( as.POSIXct(1800*(0:n),"GMT",origin="2001-01-01"), L ),
+#'   value = as.double(t(series)) )
+#' dbWriteTable(series_db, "times_values", times_values)
+#' # Fill associative array, map index to identifier
+#' indexToID_inDB <- as.character(
+#'   dbGetQuery(series_db, 'SELECT DISTINCT id FROM time_values')[,"id"] )
+#' getSeries = function(indices) {
+#'   request = "SELECT id,value FROM times_values WHERE id in ("
+#'   for (i in indices)
+#'     request = paste(request, i, ",", sep="")
+#'   request = paste(request, ")", sep="")
+#'   df_series = dbGetQuery(series_db, request)
+#'   # Assume that all series share same length at this stage
+#'   ts_length = sum(df_series[,"id"] == df_series[1,"id"])
+#'   t( as.matrix(df_series[,"value"], nrow=ts_length) )
+#' }
+#' medoids_db = claws(getSeries, K1=60, K2=6, "d8", "rel", nb_series_per_chunk=500)
+#' dbDisconnect(series_db)
+#'
+#' # All computed medoids should be the same:
+#' digest::sha1(medoids_ascii)
+#' digest::sha1(medoids_csv)
+#' digest::sha1(medoids_bin)
+#' digest::sha1(medoids_db)
+#' }
+#' @export
+claws = function(getSeries, K1, K2,
+       wf,ctype, #stage 1
+       WER="end", #stage 2
+       random=TRUE, #randomize series order?
+       ntasks=1, ncores_tasks=1, ncores_clust=4, #control parallelism
+       nb_series_per_chunk=50*K1, min_series_per_chunk=5*K1, #chunk size
+       sep=",", #ASCII input separator
+       nbytes=4, endian=.Platform$endian, #serialization (write,read)
+       verbose=FALSE)
 {
-       #TODO: setRefClass(...) to avoid copy data:
-       #http://stackoverflow.com/questions/2603184/r-pass-by-reference
-
-       #0) check arguments
-       if (!is.data.frame(data) && !is.function(data))
-               tryCatch(
-                       {
-                               if (is.character(data))
-                               {
-                                       data_con = file(data, open="r")
-                               } else if (!isOpen(data))
-                               {
-                                       open(data)
-                                       data_con = data
-                               }
-                       },
-                       error="data should be a data.frame, a function or a valid connection")
-       if (!is.integer(K) || K < 2)
-               stop("K should be an integer greater or equal to 2")
-       if (!is.integer(nb_series_per_chunk) || nb_series_per_chunk < K)
-               stop("nb_series_per_chunk should be an integer greater or equal to K")
-       if (!is.function(writeTmp) || !is.function(readTmp))
-               stop("read/writeTmp should be functional (see defaults.R)")
+       # Check/transform arguments
+       if (!is.matrix(getSeries) && !is.function(getSeries) &&
+               !methods::is(getSeries, "connection" && !is.character(getSeries)))
+       {
+               stop("'getSeries': matrix, function, file or valid connection (no NA)")
+       }
+       K1 = .toInteger(K1, function(x) x>=2)
+       K2 = .toInteger(K2, function(x) x>=2)
+       if (!is.logical(random))
+               stop("'random': logical")
+       tryCatch(
+               {ignored <- wavelets::wt.filter(wf)},
+               error = function(e) stop("Invalid wavelet filter; see ?wavelets::wt.filter"))
        if (WER!="end" && WER!="mix")
                stop("WER takes values in {'end','mix'}")
-       #concerning ncores, any non-integer type will be treated as "use parallel:detectCores()/4"
+       ntasks = .toInteger(ntasks, function(x) x>=1)
+       ncores_tasks = .toInteger(ncores_tasks, function(x) x>=1)
+       ncores_clust = .toInteger(ncores_clust, function(x) x>=1)
+       nb_series_per_chunk = .toInteger(nb_series_per_chunk, function(x) x>=K1)
+       min_series_per_chunk = .toInteger(K1, function(x) x>=K1 && x<=nb_series_per_chunk)
+       if (!is.character(sep))
+               stop("'sep': character")
+       nbytes = .toInteger(nbytes, function(x) x==4 || x==8)
+
+       # Serialize series if required, to always use a function
+       bin_dir = ".epclust.bin/"
+       dir.create(bin_dir, showWarnings=FALSE, mode="0755")
+       if (!is.function(getSeries))
+       {
+               if (verbose)
+                       cat("...Serialize time-series\n")
+               series_file = paste(bin_dir,"data",sep="") ; unlink(series_file)
+               binarize(getSeries, series_file, nb_series_per_chunk, sep, nbytes, endian)
+               getSeries = function(inds) getDataInFile(inds, series_file, nbytes, endian)
+       }
 
-       #1) acquire data (process curves, get as coeffs)
-       #TODO: for data.frame and custom function, run in parallel (connections are sequential[?!])
+       # Serialize all computed wavelets contributions onto a file
+       contribs_file = paste(bin_dir,"contribs",sep="") ; unlink(contribs_file)
        index = 1
        nb_curves = 0
+       if (verbose)
+               cat("...Compute contributions and serialize them\n")
        repeat
        {
-               coeffs_chunk = NULL
-               if (is.data.frame(data))
-               {
-                       #full data matrix
-                       if (index < nrow(data))
-                       {
-                               coeffs_chunk = curvesToCoeffs(
-                                       data[index:(min(index+nb_series_per_chunk-1,nrow(data))),], wf)
-                       }
-               } else if (is.function(data))
-               {
-                       #custom user function to retrieve next n curves, probably to read from DB
-                       coeffs_chunk = curvesToCoeffs( data(index, nb_series_per_chunk), wf )
-               } else
-               {
-                       #incremental connection
-                       #TODO: find a better way to parse than using a temp file
-                       ascii_lines = readLines(data_con, nb_series_per_chunk)
-                       if (length(ascii_lines > 0))
-                       {
-                               series_chunk_file = ".tmp/series_chunk"
-                               writeLines(ascii_lines, series_chunk_file)
-                               coeffs_chunk = curvesToCoeffs( read.csv(series_chunk_file), wf )
-                       }
-               }
-               if (is.null(coeffs_chunk))
+               series = getSeries((index-1)+seq_len(nb_series_per_chunk))
+               if (is.null(series))
                        break
-               writeTmp(coeffs_chunk)
-               nb_curves = nb_curves + nrow(coeffs_chunk)
+               contribs_chunk = curvesToContribs(series, wf, ctype)
+               binarize(contribs_chunk, contribs_file, nb_series_per_chunk, sep, nbytes, endian)
                index = index + nb_series_per_chunk
+               nb_curves = nb_curves + nrow(contribs_chunk)
        }
-       if (exists(data_con))
-               close(data_con)
+       getContribs = function(indices) getDataInFile(indices, contribs_file, nbytes, endian)
+
        if (nb_curves < min_series_per_chunk)
                stop("Not enough data: less rows than min_series_per_chunk!")
+       nb_series_per_task = round(nb_curves / ntasks)
+       if (nb_series_per_task < min_series_per_chunk)
+               stop("Too many tasks: less series in one task than min_series_per_chunk!")
 
-       #2) process coeffs (by nb_series_per_chunk) and cluster them in parallel
-       library(parallel)
-       ncores = ifelse(is.integer(ncores), ncores, parallel::detectCores()%/%4)
-       cl = parallel::makeCluster(ncores)
-       parallel::clusterExport(cl=cl, varlist=c("TODO:", "what", "to", "export?"), envir=environment())
-       #TODO: be careful of writing to a new temp file, then flush initial one, then re-use it...
-       repeat
-       {
-               #while there is jobs to do (i.e. size of tmp "file" is greater than nb_series_per_chunk)
-               nb_workers = nb_curves %/% nb_series_per_chunk
-               indices = list()
-               #indices[[i]] == (start_index,number_of_elements)
-               for (i in 1:nb_workers)
-                       indices[[i]] = c(nb_series_per_chunk*(i-1)+1, nb_series_per_chunk)
-               remainder = nb_curves %% nb_series_per_chunk
-               if (remainder >= min_series_per_chunk)
-               {
-                       nb_workers = nb_workers + 1
-                       indices[[nb_workers]] = c(nb_curves-remainder+1, nb_curves)
-               } else if (remainder > 0)
+       # Cluster contributions in parallel (by nb_series_per_chunk)
+       indices_all = if (random) sample(nb_curves) else seq_len(nb_curves)
+       indices_tasks = lapply(seq_len(ntasks), function(i) {
+               upper_bound = ifelse( i<ntasks, min(nb_series_per_task*i,nb_curves), nb_curves )
+               indices_all[((i-1)*nb_series_per_task+1):upper_bound]
+       })
+       if (verbose)
+               cat(paste("...Run ",ntasks," x stage 1 in parallel\n",sep=""))
+#      cl = parallel::makeCluster(ncores_tasks)
+#      parallel::clusterExport(cl, varlist=c("getSeries","getContribs","K1","K2",
+#              "nb_series_per_chunk","ncores_clust","synchrones_file","sep","nbytes","endian"),
+#              envir = environment())
+       # 1000*K1 indices [if WER=="end"], or empty vector [if WER=="mix"] --> series on file
+#      indices = unlist( parallel::parLapply(cl, indices_tasks, function(inds) {
+       indices = unlist( lapply(indices_tasks, function(inds) {
+#              require("epclust", quietly=TRUE)
+
+               browser() #TODO: CONTINUE DEBUG HERE
+
+               indices_medoids = clusteringTask(inds,getContribs,K1,nb_series_per_chunk,ncores_clust)
+               if (WER=="mix")
                {
-                       #spread the load among other workers
-                       #...
+                       medoids2 = computeClusters2(
+                               getSeries(indices_medoids), K2, getSeries, nb_series_per_chunk)
+                       binarize(medoids2, synchrones_file, nb_series_per_chunk, sep, nbytes, endian)
+                       return (vector("integer",0))
                }
-               li = parallel::parLapply(cl, indices, processChunk, K, WER=="mix")
-               #C) flush tmp file (current parallel processes will write in it)
-       }
-       parallel::stopCluster(cl)
+               indices_medoids
+       }) )
+#      parallel::stopCluster(cl)
 
-       #3) readTmp last results, apply PAM on it, and return medoids + identifiers
-       final_coeffs = readTmp(1, nb_series_per_chunk)
-       if (nrow(final_coeffs) == K)
+       getRefSeries = getSeries
+       synchrones_file = paste(bin_dir,"synchrones",sep="") ; unlink(synchrones_file)
+       if (WER=="mix")
        {
-               return ( list( medoids=coeffsToCurves(final_coeffs[,2:ncol(final_coeffs)]),
-                       ids=final_coeffs[,1] ) )
+               indices = seq_len(ntasks*K2)
+               #Now series must be retrieved from synchrones_file
+               getSeries = function(inds) getDataInFile(inds, synchrones_file, nbytes, endian)
+               #Contributions must be re-computed
+               unlink(contribs_file)
+               index = 1
+               if (verbose)
+                       cat("...Serialize contributions computed on synchrones\n")
+               repeat
+               {
+                       series = getSeries((index-1)+seq_len(nb_series_per_chunk))
+                       if (is.null(series))
+                               break
+                       contribs_chunk = curvesToContribs(series, wf, ctype)
+                       binarize(contribs_chunk, contribs_file, nb_series_per_chunk, sep, nbytes, endian)
+                       index = index + nb_series_per_chunk
+               }
        }
-       pam_output = getClusters(as.matrix(final_coeffs[,2:ncol(final_coeffs)]), K)
-       medoids = coeffsToCurves(pam_output$medoids, wf)
-       ids = final_coeffs[,1] [pam_output$ranks]
 
-       #4) apply stage 2 (in parallel ? inside task 2) ?)
-       if (WER == "end")
-       {
-               #from center curves, apply stage 2...
-               #TODO:
-       }
+       # Run step2 on resulting indices or series (from file)
+       if (verbose)
+               cat("...Run final // stage 1 + stage 2\n")
+       indices_medoids = clusteringTask(
+               indices, getContribs, K1, nb_series_per_chunk, ncores_tasks*ncores_clust)
+       medoids = computeClusters2(getSeries(indices_medoids),K2,getRefSeries,nb_series_per_chunk)
+
+       # Cleanup
+       unlink(bin_dir, recursive=TRUE)
 
-       return (list(medoids=medoids, ids=ids))
+       medoids
 }
 
-processChunk = function(indice, K, WER)
+#' curvesToContribs
+#'
+#' Compute the discrete wavelet coefficients for each series, and aggregate them in
+#' energy contribution across scales as described in https://arxiv.org/abs/1101.4744v2
+#'
+#' @param series Matrix of series (in rows), of size n x L
+#' @inheritParams claws
+#'
+#' @return A matrix of size n x log(L) containing contributions in rows
+#'
+#' @export
+curvesToContribs = function(series, wf, ctype)
 {
-       #1) retrieve data
-       coeffs = readTmp(indice[1], indice[2])
-       #2) cluster
-       cl = getClusters(as.matrix(coeffs[,2:ncol(coeffs)]), K)
-       #3) WER (optional)
-       #TODO:
+       L = length(series[1,])
+       D = ceiling( log2(L) )
+       nb_sample_points = 2^D
+       cont_types = c("relative","absolute")
+       ctype = cont_types[ pmatch(ctype,cont_types) ]
+       t( apply(series, 1, function(x) {
+               interpolated_curve = spline(1:L, x, n=nb_sample_points)$y
+               W = wavelets::dwt(interpolated_curve, filter=wf, D)@W
+               nrj = rev( sapply( W, function(v) ( sqrt( sum(v^2) ) ) ) )
+               if (ctype=="relative") nrj / sum(nrj) else nrj
+       }) )
 }
 
-#TODO: difficulté : retrouver courbe à partir de l'identifiant (DB ok mais le reste ?)
-#aussi : que passe-t-on aux noeuds ? curvesToCoeffs en // ?
-#enfin : WER ?!
+# Helper for main function: check integer arguments with functiional conditions
+.toInteger <- function(x, condition)
+{
+       if (!is.integer(x))
+               tryCatch(
+                       {x = as.integer(x)[1]},
+                       error = function(e) paste("Cannot convert argument",substitute(x),"to integer")
+               )
+       if (!condition(x))
+               stop(paste("Argument",substitute(x),"does not verify condition",body(condition)))
+       x
+}