R/io_functions.R

In accucor: Natural Abundance Correction of Mass Spectrometer Data

#' Natural Abundance correction for Carbon labeled samples
#'
#' @param path Path to input file.
#' @param sheet Name of sheet in xlsx file with columns 'compound',
#'      'formula', 'isotopelabel', and one column per sample. Defaults to the
#'      first sheet.
#' @param compound_database Path to compound database in csv format. Only used
#'   for classic MAVEN style input when formula is not specified.
#' @param filetype Specify file type, default is to determine by file extension.
#' @param columns_to_skip Specify column heading to skip. All other columns not
#'      named 'compound', 'formula', and 'isotopelabel' will be assumed to be
#'      sample names.
#' @param \dots Pass additional parameters to readxl::read_excel
#' @importFrom rlang .data
#' @return List containing three items: "original" data.frame which is result
#'       of read_excel, "cleaned" data.frame which with columns 'compound',
#'       'formula', 'isotope_label', label_index', followed by columns for each
#'       sample, and "isotope" which is a character indicating the isotope
#' @export
#' @examples
#' \dontrun{
#' read_elmaven_xlsx("ExcelFile", "Sheet1")
#' }
read_elmaven <-
  function(path,
           sheet = NULL,
           compound_database = NULL,
           columns_to_skip = NULL,
           filetype = NULL,
           ...) {
    if (is.null(filetype)) {
      filetype <- tools::file_ext(path)
    }

    # TODO Break this out to a function
    # Classic MAVEN style import
    if (!is.null(compound_database)) {
      compounds <- suppressMessages(readr::read_csv(compound_database))
      names(compounds)[which(tolower(names(compounds)) == "compound")] <-
        "Compound"
      names(compounds)[which(tolower(names(compounds)) == "formula")] <-
        "Formula"

      if (filetype %in% c("xls", "xlsx")) {
        InputDF <-
          suppressMessages(readxl::read_excel(
            path,
            sheet = sheet, col_names = FALSE, ...
          ))
      } else if (filetype %in% c("csv", "txt")) {
        InputDF <-
          suppressMessages(readr::read_csv(path, col_names = FALSE, ...))
      } else if (filetype %in% c("tsv")) {
        InputDF <-
          suppressMessages(readr::read_tsv(path, col_names = FALSE, ...))
      } else {
        stop(paste("Unsupported input filetype: '", filetype, "'", sep = ""))
      }

      tmpInputDF <- InputDF
      names(tmpInputDF) <- sapply(tmpInputDF[1, ], as.character)
      names(tmpInputDF)[1] <- "Compound"
      tmpInputDF$IsotopeLabel <- rep(NA, nrow(tmpInputDF))

      # TODO Fix this so it uses the proper prefixes
      tmpInputDF <-
        dplyr::mutate(tmpInputDF, IsotopeLabel = .data$Compound)

      for (i in seq_len(nrow(tmpInputDF))) {
        if (grepl("PARENT$", tmpInputDF[[i, 1]])) {
          tmpInputDF[[i, 1]] <- tmpInputDF[[i - 1, 1]]
        } else if (grepl("^\\w+-label-", tmpInputDF[[i, 1]])) {
          tmpInputDF[[i, 1]] <- tmpInputDF[[i - 1, 1]]
        }
      }
      tmpInputDF <-
        dplyr::left_join(tmpInputDF,
          dplyr::select(
            compounds,
            .data$Compound,
            .data$Formula
          ),
          by = "Compound"
        )
      tmpInputDF <-
        dplyr::filter(
          tmpInputDF,
          grepl(
            "PARENT$|^\\w+-label-",
            .data$IsotopeLabel
          )
        )
      tmpInputDF_1 <- dplyr::select(
        tmpInputDF, .data$Compound,
        .data$Formula, .data$IsotopeLabel
      )
      tmpInputDF_2 <- dplyr::select(
        tmpInputDF,
        -.data$Compound, -.data$Formula,
        -.data$IsotopeLabel
      )
      tmpInputDF_2 <-
        dplyr::mutate_if(tmpInputDF_2, is.character, as.numeric)

      InputDF <- dplyr::bind_cols(tmpInputDF_1, tmpInputDF_2)

      # TODO Convert sample data to numeric
      if (any(is.na(InputDF$Formula))) {
        stop(paste("The formula of", i, "is unknown", sep = " "))
      }

      # El-Maven style import
    } else {
      if (filetype %in% c("xls", "xlsx")) {
        InputDF <- suppressMessages(
          readxl::read_excel(path, sheet = sheet, ...)
        )
      } else if (filetype %in% c("csv", "txt")) {
        InputDF <- suppressMessages(readr::read_csv(path, ...))
      } else if (filetype %in% c("tsv")) {
        InputDF <- suppressMessages(readr::read_tsv(path, ...))
      } else {
        stop(paste("Unsupported input filetype: '", filetype, "'", sep = ""))
      }
    }

    # Remove empty rows (sometimes introduced by El-MAVEN)
    InputDF <-
      InputDF[!(apply(InputDF, 1, function(x) {
        all(is.na(x))
      })), ]

    # Created "cleaned" data frame with normalized labels
    cleaned_dataframe <-
      clean_data_frame(df = InputDF, columns_to_skip = columns_to_skip)

    # Determine isotope
    isotope <-
      determine_isotope(cleaned_dataframe$isotope_label)$isotope

    return(list(
      original = InputDF,
      cleaned = cleaned_dataframe,
      isotope = isotope
    ))
  }

#' Standardize data frame columns and data types
#'
#' @param df Data frame to clean
#' @param columns_to_skip Specify column heading to skip. All other columns not
#'      named 'compound', 'formula', and 'isotopelabel' will be assumed to be
#'      sample names.
#' @return "cleaned" data.frame which with columns 'compound', 'formula',
#'      'isotope_label', label_index', followed by columns for each sample
#' @importFrom rlang .data
clean_data_frame <- function(df, columns_to_skip = NULL) {
  # Remove columns that are not needed
  if (is.null(columns_to_skip)) {
    columns_to_skip <- c(
      "label", "goodPeakCount", "medMz", "medRt", "adductName",
      "maxQuality", "compoundId", "expectedRtDiff", "ppmDiff", "parent"
    )
  }

  # Find formula and compound columns
  formula_col_num <- which(tolower(names(df)) == "formula")
  if (rlang::is_empty(formula_col_num)) {
    stop("Unable to find column 'formula' in input data")
  }

  # Find compound column
  compound_col_num <- which(tolower(names(df)) == "compound")
  if (rlang::is_empty(compound_col_num)) {
    stop("Unable to find column 'compound' in input data")
  }
  compound_col_name <- names(df)[compound_col_num]

  # Generate label column as incremental index
  isotope_label_col_num <- which(tolower(names(df)) == "isotopelabel")
  if (rlang::is_empty(isotope_label_col_num)) {
    stop("Unable to find column 'isotopelabel' in input data")
  }
  isotope_label_col_name <- names(df)[isotope_label_col_num]
  isotope_labels <- dplyr::pull(df, isotope_label_col_num)

  sample_col_names <- names(df)[which(!(tolower(names(df)) %in%
    tolower(c(
      columns_to_skip,
      "compound",
      "formula",
      "isotopelabel",
      "metaGroupId",
      "groupId"
    ))))]
  if (length(sample_col_names) == 0) {
    stop("Unable to find sample columns in input data")
  }

  if ("metaGroupId" %in% names(df) && (!all(df$metaGroupId == 0))) {
    metaGroupId <- df$metaGroupId
  } else {
    # Generate metaGroupId
    tmp <- dplyr::group_by(df, !!as.name(compound_col_name))
    metaGroupId <- dplyr::group_indices(tmp)
    # Check to be sure there is only one peak group per compound
    tmp <- dplyr::summarise(tmp,
      peak_group_count =
        sum(grepl(
          "PARENT", !!as.name(isotope_label_col_name)
        )),
      .groups = "keep"
    )
    tmp <- dplyr::filter(tmp, .data$peak_group_count > 1)
    tmp <- dplyr::pull(tmp, !!as.name(compound_col_name))
    if (!rlang::is_empty(tmp)) {
      stop(sprintf(
        paste(
          "Multiple peak groups detected for '%s',",
          "use metaGroupId column to distinguish peak groups (El-Maven >= 0.4)"
        ),
        tmp
      ))
    }
  }

  # Create column of counts for isotopes
  # Only one type of isotope at a time is supported
  label_counts <- create_label_count(isotope_labels)

  # Combine cleaned data
  cleaned_dataframe <- dplyr::bind_cols(
    metaGroupId = as.factor(metaGroupId),
    dplyr::select(df,
      compound = dplyr::all_of(compound_col_num),
      formula = dplyr::all_of(formula_col_num),
      isotope_label = dplyr::all_of(isotope_label_col_num)
    ),
    label_index = label_counts$label_counts,
    dplyr::select(df, dplyr::all_of(sample_col_names))
  )

  return(cleaned_dataframe)
}

create_label_count <- function(isotope_labels) {
  isotope_info <- determine_isotope(isotope_labels)
  label_counts <- stringr::str_replace_all(
    isotope_labels,
    isotope_info$isotope_prefix,
    ""
  )
  label_counts <- stringr::str_replace_all(
    label_counts,
    isotope_info$parent_prefix,
    "0"
  )
  label_counts <- as.integer(label_counts)
  if (any(is.na(label_counts))) {
    bad_labels <- is.na(label_counts)
    stop(paste0(
      "Unable to parse isotope labels: ",
      paste(isotope_labels[bad_labels], collapse = ", ")
    ))
  }
  return(list(label_counts = label_counts, isotope = isotope_info$isotope))
}


determine_isotope <- function(isotope_labels) {
  if (any(grepl("^D-", isotope_labels))) {
    parent_prefix <- "C12 PARENT"
    isotope_prefix <- "D-label-"
    isotope <- "D"
  } else if (any(grepl("^D2-", isotope_labels))) {
    parent_prefix <- "C12 PARENT"
    isotope_prefix <- "D2-label-"
    isotope <- "D"
  } else if (any(grepl("^C13", isotope_labels))) {
    parent_prefix <- "C12 PARENT"
    isotope_prefix <- "C13-label-"
    isotope <- "C"
  } else if (any(grepl("^N15", isotope_labels))) {
    parent_prefix <- "C12 PARENT"
    isotope_prefix <- "N15-label-"
    isotope <- "N"
  } else {
    stop(paste(
      "Unable to determine isotope from isotopeLabel column,",
      "must be one of (C, D, or N)"
    ))
  }
  return(list(
    isotope = isotope,
    parent_prefix = parent_prefix,
    isotope_prefix = isotope_prefix
  ))
}


write_output <- function(dataframe_list, path, filetype = NULL, ...) {
  if (identical(FALSE, path)) {
    return(path)
  }

  if (is.null(path)) {
    return(path)
  }

  if (is.null(filetype)) {
    filetype <- tools::file_ext(path)
  }

  if (filetype %in% c("xls", "xlsx")) {
    output_path <- paste(
      tools::file_path_sans_ext(path),
      "_corrected.",
      filetype,
      sep = ""
    )
    message(paste("Output written to: '", output_path, "'", sep = ""))
    writexl::write_xlsx(dataframe_list, output_path, ...)
  } else if (filetype %in% c("csv", "txt", "tsv")) {
    if (filetype %in% c("csv", "txt")) {
      write_func <- readr::write_csv
    } else if (filetype %in% c("tsv")) {
      write_func <- readr::write_tsv
    }
    for (sheet in names(dataframe_list)) {
      if (tolower(sheet) == "original") {
        next
      }
      sheet_path <- paste(tools::file_path_sans_ext(path), "_", tolower(sheet),
        ".", filetype,
        sep = ""
      )
      message(paste("Output written to: '", sheet_path, "'", sep = ""))
      write_func(dataframe_list[[sheet]], sheet_path, ...)
    }
  } else {
    stop(paste("Unsupported output filetype: '", filetype, "'", sep = ""))
  }
  return(path)
}