Adding chromPeaks metadata to the Spectra output of chromPeakSpectra()

DESCRIPTION

@@ -1,5 +1,5 @@
 Package: xcms
-Version: 4.5.1
+Version: 4.5.2
 Title: LC-MS and GC-MS Data Analysis
 Description: Framework for processing and visualization of chromatographically
     separated and single-spectra mass spectral data. Imports from AIA/ANDI NetCDF,
@@ -158,4 +158,5 @@ Collate:
     'writemzdata.R'
     'writemztab.R'
     'xcmsSource.R'
-    'zzz.R'
+    'zzz.R'
+

NEWS.md

@@ -1,4 +1,13 @@
-# xcms 4.5.1
+# xcms 4.5.2
+
+## Changes in version 4.5.2
+
+- Small update to `featureSpectra()` and `chromPeakSpectra()` to allow addition
+  of `chromPeaks()` and `featuresDefinitions()` columns to be added to the
+  `Spectra` output. 
+- Tidied the `xcms` vignette, to order the filtering of features and remove 
+  the outdated normalisation paragraph.In depth discussion on this subject can 
+  be found on `metabonaut`. 
 
 ## Changes in version 4.5.1
 
@@ -13,8 +22,6 @@
 - Small fix to the .yml file for the github actions, so they do not crash on 
   warnings.
 
-
-
 ## Changes in version 4.3.3
 
 - Fix issue #755: `chromatogram()` with `msLevel = 2` fails to extract

R/AllGenerics.R

@@ -411,14 +411,19 @@ setGeneric("chromPeakData<-", function(object, value)
 #'
 #' Parameter `return.type` allows to specify the *type* of the result object.
 #' With `return.type = "Spectra"` (the default) a [Spectra] object with all
-#' matching spectra is returned. The spectra variable `"peak_id"` of the
-#' returned `Spectra` contains the ID of the chromatographic peak (i.e., the
-#' rowname of the peak in the `chromPeaks` matrix) for each spectrum.
-#' With `return.type = "Spectra"` a `List` of `Spectra` is returned. The
-#' length of the list is equal to the number of rows of `chromPeaks`. Each
-#' element of the list contains thus a `Spectra` with all spectra for one
-#' chromatographic peak (or a `Spectra` of length 0 if no spectrum was found
-#' for the respective chromatographic peak).
+#' matching spectra is returned. With `return.type = "Spectra"` a `List` of
+#' `Spectra` is returned. The length of the list is equal to the number of rows
+#' of `chromPeaks`. Each element of the list contains thus a `Spectra` with all
+#' spectra for one chromatographic peak (or a `Spectra` of length 0 if no
+#' spectrum was found for the respective chromatographic peak).
+#'
+#' Parameter `chromPeakColumns` allows the user to add specific metadata
+#' columns from the chromatographic peaks (`chromPeaks`) to the returned
+#' spectra object. This can be useful to keep information such as retention
+#' time (`rt`), m/z (`mz`). The columns will be named as they are written in the
+#' `chromPeaks` object with the prefix `"chrom_peak_"`. The *peak ID*
+#' (i.e., the row name of the peak in the `chromPeaks` matrix) is always added
+#' to the spectra object as a metadata column named `"chrom_peak_id"`.
 #'
 #' See also the *LC-MS/MS data analysis* vignette for more details and examples.
 #'
@@ -453,6 +458,11 @@ setGeneric("chromPeakData<-", function(object, value)
 #' @param return.type `character(1)` defining the type of result object that
 #'     should be returned.
 #'
+#' @param chromPeakColumns `character` vector with the names of the columns
+#'    from `chromPeaks` that should be added to the returned spectra object.
+#'    The columns will be named as they are written in the `chromPeaks` object
+#'    with a prefix `"chrom_peak_"`. Defaults to `c("mz", "rt")`.
+#'
 #' @param BPPARAM parallel processing setup. Defaults to [bpparam()].
 #'
 #' @param ... ignored.
@@ -500,10 +510,10 @@ setGeneric("chromPeakData<-", function(object, value)
 #' ms2_sps <- chromPeakSpectra(dda)
 #' ms2_sps
 #'
-#' ## spectra variable *peak_id* contain the row names of the peaks in the
+#' ## spectra variable *chrom_peak_id* contain the row names of the peaks in the
 #' ## chromPeak matrix and allow thus to map chromatographic peaks to the
 #' ## returned MS2 spectra
-#' ms2_sps$peak_id
+#' ms2_sps$chrom_peak_id
 #' chromPeaks(dda)
 #'
 #' ## Alternatively, return the result as a List of Spectra objects. This list
@@ -799,10 +809,21 @@ setGeneric("featureDefinitions<-", function(object, value)
 #' spectrum **per chromatographic peak** will be returned (hence multiple
 #' spectra per feature).
 #'
-#' The ID of each chromatographic peak (i.e. its row name in `chromPeaks`)
-#' and each feature (i.e., its row name in `featureDefinitions`) are
-#' available in the returned [Spectra()] with spectra variables `"peak_id"`
-#' and `"feature_id"`, respectively.
+#' The information from `featureDefinitions` for each feature can be included
+#' in the returned [Spectra()] object using the `featureColumns` parameter.
+#' This is useful for keeping details such as the median retention time (`rtmed`)
+#' or median m/z (`mzmed`). The columns will retain their names as specified
+#' in the `featureDefinitions` object, prefixed by `"feature_"`
+#' (e.g., `"feature_mzmed"`). Additionally, the *feature ID* (i.e., the row
+#' name of the feature in the `featureDefinitions` data.frame) is always added
+#' as a metadata column named `"feature_id"`.
+#'
+#' See also [chromPeakSpectra()], as it supports a similar parameter for
+#' including columns from the chromatographic peaks in the returned spectra object.
+#' These parameters can be used in combination to include information from both
+#' the chromatographic peaks and the features in the returned [Spectra()].
+#' The *peak ID* (i.e., the row name of the peak in the `chromPeaks` matrix)
+#' is added as a metadata column named `"chrom_peak_id"`.
 #'
 #' @param object [XcmsExperiment] or [XCMSnExp] object with feature defitions.
 #'
@@ -815,6 +836,12 @@ setGeneric("featureDefinitions<-", function(object, value)
 #'     `featureDefinitions(x)`). This parameter overrides `skipFilled` and is
 #'     only supported for `return.type` being either `"Spectra"` or `"List"`.
 #'
+#' @param featureColumns `character` vector with the names of the columns
+#'     from `featureDefinitions` that should be added to the returned spectra
+#'     object. The columns will be named as they are written in the
+#'    `featureDefinitions` object with the prefix `"feature_`.
+#'     Defaults to `c("mzmed", "rtmed")`.
+#'
 #' @param ... additional arguments to be passed along to [chromPeakSpectra()],
 #'     such as `method`.
 #'
@@ -825,7 +852,7 @@ setGeneric("featureDefinitions<-", function(object, value)
 #' the order and the length matches parameter `features` (or if no `features`
 #' is defined the order of the features in `featureDefinitions(object)`).
 #'
-#' Spectra variables `"peak_id"` and `"feature_id"` define to which
+#' Spectra variables `"chrom_peak_id"` and `"feature_id"` define to which
 #' chromatographic peak or feature each individual spectrum is associated
 #' with.
 #'

R/XcmsExperiment-functions.R

@@ -793,10 +793,16 @@
                                                  "largest_bpi"),
                                    msLevel = 2L, expandRt = 0, expandMz = 0,
                                    ppm = 0, skipFilled = FALSE,
-                                   peaks = integer(), BPPARAM = bpparam()) {
+                                   peaks = integer(),
+                                   chromPeakColumns = c("rt", "mz"),
+                                   BPPARAM = bpparam()) {
     method <- match.arg(method)
-    pks <- .chromPeaks(x)[, c("mz", "mzmin", "mzmax", "rt",
-                              "rtmin", "rtmax", "maxo", "sample")]
+    if (!all(chromPeakColumns %in% colnames(.chromPeaks(x))))
+        stop("One or more of the columns in 'chromPeakColumns' are not ",
+             "available in the 'chromPeaks' data.")
+    pks <- .chromPeaks(x)[, union(c("mz", "mzmin", "mzmax", "rt",
+                              "rtmin", "rtmax", "maxo", "sample"),
+                              chromPeakColumns)]
     if (ppm != 0)
         expandMz <- expandMz + pks[, "mz"] * ppm / 1e6
     if (expandMz[1L] != 0) {
@@ -818,7 +824,7 @@
     res <- bpmapply(
         split.data.frame(pks, f),
         split(spectra(x), factor(fromFile(x), levels = levels(f))),
-        FUN = function(pk, sp, msLevel, method) {
+        FUN = function(pk, sp, msLevel, method, chromPeakColumns) {
             sp <- filterMsLevel(sp, msLevel)
             idx <- switch(
                 method,
@@ -829,14 +835,35 @@
                 largest_bpi = .spectra_index_list_largest_bpi(sp, pk, msLevel))
             ids <- rep(rownames(pk), lengths(idx))
             res <- sp[unlist(idx)]
-            res$peak_id <- ids
+            pk_data <- as.data.frame(pk[ids, chromPeakColumns, drop = FALSE])
+            pk_data$id <- ids
+            colnames(pk_data) <- paste0("chrom_peak_", colnames(pk_data))
+            res <- .add_spectra_data(res, pk_data)
             res
         },
-        MoreArgs = list(msLevel = msLevel, method = method),
+        MoreArgs = list(msLevel = msLevel, method = method,
+                        chromPeakColumns = chromPeakColumns),
         BPPARAM = BPPARAM)
     Spectra:::.concatenate_spectra(res)
 }
 
+#' @param x `Spectra` object.
+#'
+#' @param data `data.frame` or `matrix` with the data to be added to the
+#'     spectra object.
+#'
+#' @noRd
+.add_spectra_data <- function(x, data) {
+    if (is(data, "matrix"))
+        data <- as.data.frame(data)
+    if (nrow(data) != length(x))
+        stop("Length of 'data' does not match the number of spectra in 'x'")
+    for (i in colnames(data)) {
+        x[[i]] <- data[, i]
+    }
+    x
+}
+
 #' @param peaks `matrix` with chrom peaks.
 #'
 #' @param peakIdx `list` of `integer` indices defining which chromatographic

R/XcmsExperiment.R

@@ -1229,6 +1229,7 @@ setMethod(
                                 "largest_tic", "largest_bpi"),
              msLevel = 2L, expandRt = 0, expandMz = 0, ppm = 0,
              skipFilled = FALSE, peaks = character(),
+             chromPeakColumns = c("rt", "mz"),
              return.type = c("Spectra", "List"), BPPARAM = bpparam()) {
         if (hasAdjustedRtime(object))
             object <- applyAdjustedRtime(object)
@@ -1244,14 +1245,15 @@ setMethod(
         else pkidx <- integer()
         res <- .mse_spectra_for_peaks(object, method, msLevel, expandRt,
                                       expandMz, ppm, skipFilled, pkidx,
+                                      chromPeakColumns,
                                       BPPARAM)
         if (!length(pkidx))
             peaks <- rownames(.chromPeaks(object))
         else peaks <- rownames(.chromPeaks(object))[pkidx]
         if (return.type == "Spectra")
-            res <- res[as.matrix(findMatches(peaks, res$peak_id))[, 2L]]
+            res <- res[as.matrix(findMatches(peaks, res$chrom_peak_id))[, 2L]]
         else
-            as(split(res, factor(res$peak_id, levels = peaks)), "List")
+            as(split(res, factor(res$chrom_peak_id, levels = peaks)), "List")
     })
 
 #' @rdname reconstructChromPeakSpectra
@@ -1773,11 +1775,16 @@ setMethod(
     "featureSpectra", "XcmsExperiment",
     function(object, msLevel = 2L, expandRt = 0, expandMz = 0, ppm = 0,
              skipFilled = FALSE, return.type = c("Spectra", "List"),
-             features = character(), ...) {
+             features = character(),
+             featureColumns = c("rtmed", "mzmed"),
+             ...) {
         return.type <- match.arg(return.type)
         if (!hasFeatures(object))
             stop("No feature definitions present. Please run ",
                  "'groupChromPeaks' first.")
+        if (!all(featureColumns %in% colnames(featureDefinitions(object))))
+            stop("One or more of the requested 'featureColumns' are not ",
+                 "present in the feature definitions.")
         if (hasAdjustedRtime(object))
             object <- applyAdjustedRtime(object)
         features_all <- rownames(featureDefinitions(object))
@@ -1794,11 +1801,15 @@ setMethod(
             expandMz = expandMz, ppm = ppm, skipFilled = skipFilled,
             peaks = unique(pindex), ...)
         mtch <- as.matrix(
-            findMatches(sps$peak_id, rownames(.chromPeaks(object))[pindex]))
+            findMatches(sps$chrom_peak_id,
+                        rownames(.chromPeaks(object))[pindex]))
         sps <- sps[mtch[, 1L]]
         fid <- rep(
             ufeatures, lengths(featureDefinitions(object)$peakidx[findex]))
-        sps$feature_id <- fid[mtch[, 2L]]
+        f_data <- featureDefinitions(object)[fid[mtch[, 2L]], featureColumns]
+        f_data$id <- fid[mtch[, 2L]]
+        colnames(f_data) <- paste0("feature_", colnames(f_data))
+        sps <- .add_spectra_data(sps, f_data)
         if (return.type == "List") {
             sps <- List(split(sps, f = factor(sps$feature_id,
                                               levels = ufeatures)))

R/do_adjustRtime-functions.R

@@ -874,7 +874,7 @@ NULL
                       resid_ratio = 3,
                       zero_weight = 10,
                       bs = "tp"){
-    rt_map <- rt_map[order(rt_map$obs), ]
+    rt_map <- rt_map[order(rt_map$obs), c("ref", "obs")]
     # add first row of c(0,0) to set a fix timepoint.
     rt_map <- rbind(c(0,0), rt_map)
     weights <- rep(1, nrow(rt_map))