projects / epclust.git / blame
| Commit | Line | Data |
|---|---|---|
| 5c652979 BA |
1 | computeCoeffs = function(data, index, nb_series_per_chunk, wf) |
| 2 | { | |
| 3 | coeffs_chunk = NULL | |
| 4 | if (is.data.frame(data) && index < nrow(data)) | |
| 5 | { | |
| 6 | #full data matrix | |
| 7 | coeffs_chunk = curvesToCoeffs( | |
| 8 | data[index:(min(index+nb_series_per_chunk-1,nrow(data))),], wf) | |
| 9 | } | |
| 10 | else if (is.function(data)) | |
| 11 | { | |
| 12 | #custom user function to retrieve next n curves, probably to read from DB | |
| 13 | coeffs_chunk = curvesToCoeffs( data(rank=(index-1)+seq_len(nb_series_per_chunk)), wf ) | |
| 14 | } | |
| 15 | else if (exists(data_con)) | |
| 16 | { | |
| 17 | #incremental connection ; TODO: more efficient way to parse than using a temp file | |
| 18 | ascii_lines = readLines(data_con, nb_series_per_chunk) | |
| 19 | if (length(ascii_lines > 0)) | |
| 20 | { | |
| 21 | series_chunk_file = ".series_chunk" | |
| 22 | writeLines(ascii_lines, series_chunk_file) | |
| 23 | coeffs_chunk = curvesToCoeffs( read.csv(series_chunk_file), wf ) | |
| 24 | unlink(series_chunk_file) | |
| 25 | } | |
| 26 | } | |
| 27 | coeffs_chunk | |
| 28 | } | |
| 29 | ||
| 74f571a7 | 30 | #NOTE: always keep ID in first column (...? is it good ?!) |
| 5c652979 BA |
31 | curvesToCoeffs = function(series, wf) |
| 32 | { | |
| 33 | if (!require(wavelets, quietly=TRUE)) | |
| 34 | stop("Couldn't load wavelets library") | |
| 35 | L = length(series[1,]) | |
| 36 | D = ceiling( log2(L-1) ) | |
| 37 | nb_sample_points = 2^D | |
| 38 | #TODO: parallel::parApply() ?! | |
| 39 | res = apply(series, 1, function(x) { | |
| 40 | interpolated_curve = spline(1:(L-1), x[2:L], n=nb_sample_points)$y | |
| 41 | W = wavelets::dwt(interpolated_curve, filter=wf, D)@W | |
| 42 | nrj_coeffs = rev( sapply( W, function(v) ( sqrt( sum(v^2) ) ) ) ) | |
| 43 | return ( c(x[1], nrj_coeffs) ) | |
| 44 | }) | |
| 45 | return (as.data.frame(res)) | |
| 46 | } |