Browse code

export colCoxTests

Ellis Patrick authored on 06/09/2022 22:57:36
Showing 4 changed files

... ...
@@ -21,6 +21,7 @@ export(available)
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 export(calcCVperformance)
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 export(calcExternalPerformance)
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 export(chosenFeatureNames)
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+export(colCoxTests)
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 export(crossValidate)
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 export(distribution)
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 export(edgesToHubNetworks)
... ...
@@ -90,7 +91,6 @@ import(grid)
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 import(methods)
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 import(utils)
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 importFrom(S4Vectors,as.data.frame)
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-importFrom(S4Vectors,combineRows)
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 importFrom(S4Vectors,do.call)
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 importFrom(S4Vectors,mcols)
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 importFrom(dplyr,mutate)
... ...
@@ -81,6 +81,26 @@ fastCox <- function(X, y, learnind, criterion, ...) {
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 # equivalent to genefilter::rowttests for the cox model.  This is much faster
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 # than calling coxph for each row of a ##igh-dimensional matrix.
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+
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+######################################
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+######################################
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+#' A function to perform fast cox proportional hazard model tests
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+#'
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+#' @param x matrix with variables as columns.
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+#' @param y matrix with first column as time and second column as event.
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+#' @param option whether to use the fast or slow method.
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+#'
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+#' @return CrossValParams object
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+#' @export
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+#'
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+#' @examples
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+#' data(asthma)
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+#' time <- ppois(nrow(measurements),100)
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+#' status <- sample(c(0,1), nrow(measurements), replace = TRUE)
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+#' x = measurements
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+#' y = cbind(time, status)
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+#' output <- colCoxTests(x, y, "fast")
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+#' @export
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 colCoxTests <- function(X, y, option = c("fast", "slow"), ...) {
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   option <- match.arg(option)
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   if (identical(option, "fast")) {
... ...
@@ -1,3 +1,152 @@
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+# Operates on an input data frame, to extract the outcome column(s) and return
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+# a list with the table of covariates in one element and the outcome in another.
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+# The outcome need to be removed from the data table before predictor training!
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+.splitDataAndOutcome <- function(measurements, outcome, restrict = NULL)
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+{ # DataFrame's outcome variable can be character or factor, so it's a bit involved.
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+  if(is.character(outcome) && length(outcome) > 3 && length(outcome) != nrow(measurements))
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+    stop("'outcome' is a character variable but has more than one element. Either provide a\n",
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+         "       one to three column names or a factor of the same length as the number of samples.")
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+
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+  ## String specifies the name of a single outcome column, typically a class.
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+  if(is.character(outcome) && length(outcome) == 1)
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+  {
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+    outcomeColumn <- match(outcome, colnames(measurements))
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+    if(is.na(outcomeColumn))
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+      stop("Specified column name of outcome is not present in the data table.")
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+    outcome <- measurements[, outcomeColumn]
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+    measurements <- measurements[, -outcomeColumn, drop = FALSE]
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+    # R version 4 and greater no longer automatically casts character columns to factors because stringsAsFactors
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+    # is FALSE by default, so it is more likely to be character format these days. Handle it.
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+    if(class(outcome) != "factor") # Assume there will be no ordinary regression prediction tasks ... for now.
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+      outcome <- factor(outcome)
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+  }
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+  
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+  # survival's Surv constructor has two inputs for the popular right-censored data and
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+  # three inputs for less-common interval data.
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+  if(is.character(outcome) && length(outcome) %in% 2:3)
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+  {
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+    outcomeColumns <- match(outcome, colnames(measurements))
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+    if(any(is.na(outcomeColumns)))
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+      stop("Specified column names of outcome is not present in the data table.")
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+    outcome <- measurements[, outcomeColumns]
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+    measurements <- measurements[, -outcomeColumns, drop = FALSE]
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+  }
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+  
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+  if(is(outcome, "factor") && length(outcome) > 3 & length(outcome) < nrow(measurements))
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+    stop("The length of outcome is not equal to the number of samples.")
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+  
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+  ## A vector of characters was input by the user. Ensure that it is a factor.
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+  if(is.character(outcome) & length(outcome) == nrow(measurements))
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+    outcome <- factor(outcome)
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+  
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+  # Outcome has columns, so it is tabular. It is inferred to represent survival data.
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+  if(!is.null(ncol(outcome)) && ncol(outcome) %in% 2:3)
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+  {
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+    # Assume that event status is in the last column (second for two columns, third for three columns)
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+    numberEventTypes <- length(unique(outcome[, ncol(outcome)]))
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+    # Could be one or two kinds of events. All events might be uncensored or censored
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+    # in a rare but not impossible scenario.
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+    if(numberEventTypes > 2)
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+      stop("Number of distinct event types in the last column exceeds 2 but must be 1 or 2.")
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+      
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+    if(ncol(outcome) == 2) # Typical, right-censored survival data.
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+      outcome <- survival::Surv(outcome[, 1], outcome[, 2])
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+    else # Three columns. Therefore, counting process data.
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+      outcome <- survival::Surv(outcome[, 1], outcome[, 2], outcome[, 3])
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+  }
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+  
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+  if(!is.null(restrict))
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+  {
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+    isDesiredClass <- sapply(measurements, function(column) is(column, restrict))
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+    measurements <- measurements[, isDesiredClass, drop = FALSE]
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+    if(ncol(measurements) == 0)
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+      stop(paste("No features are left after restricting to", restrict, "but at least one must be."))
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+  }
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+
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+  list(measurements = measurements, outcome = outcome)
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+}
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+
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+# Function to convert a MultiAssayExperiment object into a flat DataFrame table, to enable it
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+# to be used in typical model building functions.
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+# Returns a list with a covariate table and and outcome vector/table, or just a covariate table
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+# in the case the input is a test data set.
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+.MAEtoWideTable <- function(measurements, targets = NULL, outcomeColumns = NULL, restrict = "numeric")
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+{
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+  if(is.null(targets))
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+    stop("'targets' is not specified but must be.")
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+  if(is.null(outcomeColumns))
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+    stop("'outcomeColumns' is not specified but must be.")    
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+  if(!all(targets %in% c(names(measurements), "sampleInfo")))
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+    stop("Some table names in 'targets' are not assay names in 'measurements' or \"sampleInfo\".")
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+  sampleInfoColumns <- colnames(MultiAssayExperiment::colData(measurements))
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+  if(!missing(outcomeColumns) & !all(outcomeColumns %in% sampleInfoColumns))
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+    stop("Not all column names specified by 'outcomeColumns' found in sample information table.")  
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+
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+  if("sampleInfo" %in% targets)
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+  {
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+    targets <- targets[targets != "sampleInfo"]
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+    sampleInfoColumnsTrain <- sampleInfoColumns
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+  } else {
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+    sampleInfoColumnsTrain <- NULL
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+  }
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+  
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+  if(length(targets) > 0)
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+  {
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+    measurements <- measurements[, , targets]
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+  
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+    # Get all desired measurements tables and sample information columns (other than the columns representing outcome).
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+    # These form the independent variables to be used for making predictions with.
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+    # Variable names will have names like RNA:BRAF for traceability.
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+    dataTable <- MultiAssayExperiment::wideFormat(measurements, colDataCols = union(sampleInfoColumnsTrain, outcomeColumns), check.names = FALSE, collapse = ':')
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+    rownames(dataTable) <- dataTable[, "primary"]
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+    S4Vectors::mcols(dataTable)[, "sourceName"] <- gsub("colDataCols", "sampleInfo", S4Vectors::mcols(dataTable)[, "sourceName"])
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+    colnames(S4Vectors::mcols(dataTable))[1] <- "assay"
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+  
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+    # Sample information variable names not included in column metadata of wide table but only as row names of it.
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+    # Create a combined column named "feature" which has feature names of the assays as well as the sample information.
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+    S4Vectors::mcols(dataTable)[, "feature"] <- as.character(S4Vectors::mcols(dataTable)[, "rowname"])
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+    missingIndices <- is.na(S4Vectors::mcols(dataTable)[, "feature"])
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+    S4Vectors::mcols(dataTable)[missingIndices, "feature"] <- colnames(dataTable)[missingIndices]
110
+    
111
+    # Finally, a column annotation recording variable name and which table it originated from for all of the source tables.
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+    S4Vectors::mcols(dataTable) <- S4Vectors::mcols(dataTable)[, c("assay", "feature")]
113
+  } else { # Must have only been sample information data.
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+    dataTable <- MultiAssayExperiment::colData(measurements)
115
+  }
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+  if(!is.null(outcomeColumns)) outcome <- dataTable[, outcomeColumns]
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+  
118
+  if(!is.null(restrict))
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+  {
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+    isDesiredClass <- sapply(dataTable, function(column) is(column, restrict))
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+    dataTable <- dataTable[, isDesiredClass, drop = FALSE]
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+    if(ncol(dataTable) == 0)
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+      stop(paste("No features are left after restricting to", restrict, "but at least one must be."))
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+  }
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+
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+  # Only return independent variables in dataTable for making classifications with.
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+  # "primary" column is auto-generated by sample information table row names and a duplicate.
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+  dropColumns <- na.omit(match(c("primary", outcomeColumns), colnames(dataTable)))
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+  if(length(dropColumns) > 0) dataTable <- dataTable[, -dropColumns]
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+  
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+  # Training data table and outcome for training data.
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+  if(!is.null(outcomeColumns))
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+      list(dataTable = dataTable, outcome = outcome)
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+  else # Only test data table for test data input.
135
+    dataTable
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+}
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+
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+# For classifiers which use one single function for inputting a training and a testing table,
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+# and work only for the numeric data type, this checks whether the training and testing tables 
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+# both have the same set of features and there are at least some numeric features to use,
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+# after they have been filtered by another function which splits the covariates and the outcome from the input.
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+.checkVariablesAndSame <- function(trainingMatrix, testingMatrix)
143
+{
144
+  if(ncol(trainingMatrix) == 0) # Filtering of table removed all columns, leaving nothing to classify with.
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+    stop("No variables in data tables specified by \'targets\' are numeric.")
146
+  else if(ncol(trainingMatrix) != ncol(testingMatrix))
147
+    stop("Training data set and testing data set contain differing numbers of features.")  
148
+}
149
+
1 150
 # Creates two lists of lists. First has training samples, second has test samples for a range
2 151
 # of different cross-validation schemes.
3 152
 #' @import utils
... ...
@@ -106,6 +255,7 @@
106 255
   tuneParams <- modellingParams@selectParams@tuneParams
107 256
   performanceType <- tuneParams[["performanceType"]]
108 257
   topNfeatures <- tuneParams[["nFeatures"]]
258
+  tuneMode <- ifelse("tuneMode" %in% names(tuneParams), tuneParams[["tuneMode"]], crossValParams@tuneMode)
109 259
   tuneParams <- tuneParams[-match(c("performanceType", "nFeatures"), names(tuneParams))] # Only used as evaluation metric.
110 260
   
111 261
   # Make selectParams NULL, since we are currently doing selection and it shouldn't call
... ...
@@ -132,17 +282,17 @@
132 282
       do.call(featureRanking, paramList)
133 283
     })
134 284
     
135
-    if(attr(featureRanking, "name") == "previousSelection") # Actually selection not ranking.
285
+    if(featureRanking@generic == "previousSelection") # Actually selection not ranking.
136 286
       return(list(NULL, rankings[[1]], NULL))
137 287
     
138
-    if(crossValParams@tuneMode == "none") # No parameters to choose between.
288
+    if(tuneMode == "none") # Actually selection not ranking.
139 289
         return(list(NULL, rankings[[1]], NULL))
140 290
     
141 291
     tuneParamsTrain <- list(topN = topNfeatures)
142 292
     tuneParamsTrain <- append(tuneParamsTrain, modellingParams@trainParams@tuneParams)
143 293
     tuneCombosTrain <- expand.grid(tuneParamsTrain, stringsAsFactors = FALSE)  
144 294
     modellingParams@trainParams@tuneParams <- NULL
145
-    allPerformanceTables <- lapply(rankings, function(rankingsVariety)
295
+    bestPerformers <- sapply(rankings, function(rankingsVariety)
146 296
     {
147 297
       # Creates a matrix. Columns are top n features, rows are varieties (one row if None).
148 298
       performances <- sapply(1:nrow(tuneCombosTrain), function(rowIndex)
... ...
@@ -182,22 +332,20 @@
182 332
        })
183 333
 
184 334
         bestOne <- ifelse(betterValues == "lower", which.min(performances)[1], which.max(performances)[1])
185
-        list(data.frame(tuneCombosTrain, performance = performances), bestOne)
335
+        c(bestOne, performances[bestOne])
186 336
       })
187 337
 
188
-      tablesBestMetrics <- sapply(allPerformanceTables, function(tableIndexPair) tableIndexPair[[1]][tableIndexPair[[2]], "performance"])
189
-      tunePick <- ifelse(betterValues == "lower", which.min(tablesBestMetrics)[1], which.max(tablesBestMetrics)[1])
338
+      tunePick <- ifelse(betterValues == "lower", which.min(bestPerformers[2, ])[1], which.max(bestPerformers[2, ])[1])
190 339
       
191 340
       if(verbose == 3)
192 341
          message("Features selected.")
193 342
       
194
-      tuneDetails <- allPerformanceTables[[tunePick]] # List of length 2.
343
+      tuneRow <- tuneCombosTrain[bestPerformers[1, tunePick], , drop  = FALSE]
344
+      if(ncol(tuneRow) > 1) tuneDetails <- tuneRow[, -1, drop = FALSE] else tuneDetails <- NULL
195 345
       
196 346
       rankingUse <- rankings[[tunePick]]
197
-      selectionIndices <- rankingUse[1:(tuneDetails[[1]][tuneDetails[[2]], "topN"])]
347
+      selectionIndices <- rankingUse[1:tuneRow[, "topN"]]
198 348
       
199
-      names(tuneDetails) <- c("tuneCombinations", "bestIndex")
200
-      colnames(tuneDetails[[1]])[ncol(tuneDetails[[1]])] <- performanceType
201 349
       list(ranked = rankingUse, selected = selectionIndices, tune = tuneDetails)
202 350
     } else if(is.list(featureRanking)) { # It is a list of functions for ensemble selection.
203 351
       featuresIndiciesLists <- mapply(function(selector, selParams)
... ...
@@ -240,7 +388,8 @@
240 388
       
241 389
       list(NULL, selectionIndices, NULL)
242 390
     } else { # Previous selection
243
-      selectedFeatures <- list(NULL, selectionIndices, NULL)
391
+      selectedFeatures <- 
392
+      list(NULL, selectionIndices, NULL)
244 393
     }
245 394
 }
246 395
 
... ...
@@ -256,10 +405,10 @@
256 405
 
257 406
 # Code to create a function call to a training function. Might also do training and testing
258 407
 # within the same function, so test samples are also passed in case they are needed.
259
-.doTrain <- function(measurementsTrain, outcomeTrain, measurementsTest, outcomeTest, crossValParams, modellingParams, verbose)
408
+.doTrain <- function(measurementsTrain, outcomeTrain, measurementsTest, outcomeTest, modellingParams, verbose)
260 409
 {
261
-  tuneDetails <- NULL
262
-  if(!is.null(modellingParams@trainParams@tuneParams) && is.null(modellingParams@selectParams))
410
+  tuneChosen <- NULL
411
+  if(!is.null(modellingParams@trainParams@tuneParams) && is.null(modellingParams@selectParams@tuneParams))
263 412
   {
264 413
     performanceType <- modellingParams@trainParams@tuneParams[["performanceType"]]
265 414
     modellingParams@trainParams@tuneParams <- modellingParams@trainParams@tuneParams[-match("performanceType", names(modellingParams@trainParams@tuneParams))]
... ...
@@ -271,16 +420,16 @@
271 420
       modellingParams@trainParams@otherParams <- c(modellingParams@trainParams@otherParams, as.list(tuneCombos[rowIndex, ]))
272 421
       if(crossValParams@tuneMode == "Resubstitution")
273 422
       {
274
-        result <- runTest(measurementsTrain, outcomeTrain, measurementsTrain, outcomeTrain,
423
+        result <- runTest(measurementsTrain, outcomeTrain, measurementsTest, outcomeTest,
275 424
                           crossValParams = NULL, modellingParams,
276 425
                           verbose = verbose, .iteration = "internal")
277 426
         
278 427
         predictions <- result[["predictions"]]
279 428
         if(class(predictions) == "data.frame")
280
-          predictedOutcome <- predictions[, colnames(predictions) %in% c("class", "risk")]
429
+          predictedOutcome <- predictions[, "outcome"]
281 430
         else
282 431
           predictedOutcome <- predictions
283
-        calcExternalPerformance(outcomeTrain, predictedOutcome, performanceType)
432
+        calcExternalPerformance(outcomeTest, predictedOutcome, performanceType)
284 433
       } else {
285 434
         result <- runTests(measurementsTrain, outcomeTrain,
286 435
                            crossValParams, modellingParams,
... ...
@@ -289,18 +438,13 @@
289 438
         median(performances(result)[[performanceType]])
290 439
       }
291 440
     })
292
-    allPerformanceTable <- data.frame(tuneCombos, performances)
293
-    colnames(allPerformanceTable)[ncol(allPerformanceTable)] <- performanceType
294
-    
295 441
     betterValues <- .ClassifyRenvir[["performanceInfoTable"]][.ClassifyRenvir[["performanceInfoTable"]][, "type"] == performanceType, "better"]
296 442
     bestOne <- ifelse(betterValues == "lower", which.min(performances)[1], which.max(performances)[1])
297 443
     tuneChosen <- tuneCombos[bestOne, , drop = FALSE]
298
-    tuneDetails <- list(tuneCombos, bestOne)
299
-    names(tuneDetails) <- c("tuneCombinations", "bestIndex")
300 444
     modellingParams@trainParams@otherParams <- tuneChosen
301 445
   }
302 446
 
303
-    if (!"previousTrained" %in% attr(modellingParams@trainParams@classifier, "name")) 
447
+  if(modellingParams@trainParams@classifier@generic != "previousTrained")
304 448
     # Don't name these first two variables. Some classifier functions might use classesTrain and others use outcomeTrain.
305 449
     paramList <- list(measurementsTrain, outcomeTrain)
306 450
   else # Don't pass the measurements and classes, because a pre-existing classifier is used.
... ...
@@ -315,7 +459,7 @@
315 459
   if(verbose >= 2)
316 460
     message("Training completed.")  
317 461
   
318
-  list(model = trained, tune = tuneDetails)
462
+  list(model = trained, tune = tuneChosen)
319 463
 }
320 464
 
321 465
 # Creates a function call to a prediction function.
... ...
@@ -384,6 +528,15 @@
384 528
 # by user-specified values.
385 529
 .filterCharacteristics <- function(characteristics, autoCharacteristics)
386 530
 {
531
+  # Remove duplication of values for classifiers that have one function for training and 
532
+  # one function for prediction.
533
+  if("Classifier Name" %in% autoCharacteristics[, "characteristic"] && "Predictor Name" %in% autoCharacteristics[, "characteristic"])
534
+  {
535
+    classRow <- which(autoCharacteristics[, "characteristic"] == "Classifier Name")
536
+    predRow <- which(autoCharacteristics[, "characteristic"] == "Predictor Name")
537
+    if(autoCharacteristics[classRow, "value"] == autoCharacteristics[predRow, "value"])
538
+      autoCharacteristics <- autoCharacteristics[-predRow, ]
539
+  }
387 540
   # Overwrite automatically-chosen names with user's names.
388 541
   if(nrow(autoCharacteristics) > 0 && nrow(characteristics) > 0)
389 542
   {
... ...
@@ -407,6 +560,36 @@
407 560
   plotData
408 561
 }
409 562
 
563
+# Summary of the features used and the total number of them, no matter if they are a simple type
564
+# or something more complex like Pairs or feature sets.
565
+.summaryFeatures <- function(measurements)
566
+{
567
+  # MultiAssayExperiment has feature details in mcols.
568
+  if(!is.null(S4Vectors::mcols(measurements)))
569
+  {
570
+    originalInfo <- S4Vectors::mcols(measurements)
571
+    featureNames <- S4Vectors::mcols(measurements)[, "feature"]
572
+    assays <- unique(S4Vectors::mcols(measurements)[, "assay"])
573
+    renamedInfo <- S4Vectors::mcols(measurements)
574
+    renamedAssays <- paste("Assay", seq_along(assays), sep = '')
575
+    for(assay in assays)
576
+    {
577
+      rowsAssay <- which(renamedInfo[, "assay"] == assay)
578
+      renamedInfo[rowsAssay, "feature"] <- paste("Feature", seq_along(rowsAssay), sep = '')
579
+      renamedInfo[rowsAssay, "assay"] <- renamedAssays[match(assay, assays)]
580
+    }
581
+    featuresInfo <- S4Vectors::DataFrame(originalInfo, renamedInfo)
582
+    colnames(featuresInfo) <- c("Original Assay", "Original Feature", "Renamed Assay", "Renamed Feature")
583
+    featuresInfo <- cbind(originalInfo, featuresInfo)
584
+  } else {
585
+    originalFeatures <- colnames(measurements)
586
+    renamedInfo <- paste("Feature", seq_along(measurements), sep = '')
587
+    featuresInfo <- S4Vectors::DataFrame(originalFeatures, renamedInfo)
588
+    colnames(featuresInfo) <- c("Original Feature", "Renamed Feature")
589
+  }
590
+  featuresInfo
591
+}
592
+
410 593
 # Function to identify the parameters of an S4 method.
411 594
 .methodFormals <- function(f, signature) {
412 595
   tryCatch({
... ...
@@ -477,53 +660,6 @@
477 660
   list(measurementsTrain = measurementsTrain, classesTrain = classesTrain)
478 661
 }
479 662
 
480
-.transformKeywordToFunction <- function(keyword)
481
-{
482
-  switch(
483
-        keyword,
484
-        "none" = NULL,
485
-        "diffLoc" = subtractFromLocation
486
-    )
487
-}
488
-
489
-.selectionKeywordToFunction <- function(keyword)
490
-{
491
-  switch(
492
-        keyword,
493
-        "none" = NULL,
494
-        "t-test" = differentMeansRanking,
495
-        "limma" = limmaRanking,
496
-        "edgeR" = edgeRranking,
497
-        "Bartlett" = bartlettRanking,
498
-        "Levene" = leveneRanking,
499
-        "DMD" = DMDranking,
500
-        "likelihoodRatio" = likelihoodRatioRanking,
501
-        "KS" = KolmogorovSmirnovRanking,
502
-        "KL" = KullbackLeiblerRanking,
503
-        "CoxPH" = coxphRanking,
504
-        "selectMulti" = selectMulti
505
-    )
506
-}
507
-
508
-.classifierKeywordToParams <- function(keyword)
509
-{
510
-    switch(
511
-        keyword,
512
-        "randomForest" = RFparams(),
513
-        "randomSurvivalForest" = RSFparams(),
514
-        "GLM" = GLMparams(),
515
-        "elasticNetGLM" = elasticNetGLMparams(),
516
-        "SVM" = SVMparams(),
517
-        "NSC" = NSCparams(),
518
-        "DLDA" = DLDAparams(),
519
-        "naiveBayes" = naiveBayesParams(),
520
-        "mixturesNormals" = mixModelsParams(),
521
-        "kNN" = kNNparams(),
522
-        "CoxPH" = coxphParams(),
523
-        "CoxNet" = coxnetParams()
524
-    )    
525
-}
526
-
527 663
 .dlda <- function(x, y, prior = NULL){ # Remove this once sparsediscrim is reinstated to CRAN.
528 664
   obj <- list()
529 665
   obj$labels <- y
530 666
new file mode 100644
... ...
@@ -0,0 +1,29 @@
1
+% Generated by roxygen2: do not edit by hand
2
+% Please edit documentation in R/rankingCoxPH.R
3
+\name{colCoxTests}
4
+\alias{colCoxTests}
5
+\title{A function to perform fast cox proportional hazard model tests}
6
+\usage{
7
+colCoxTests(X, y, option = c("fast", "slow"), ...)
8
+}
9
+\arguments{
10
+\item{y}{matrix with first column as time and second column as event.}
11
+
12
+\item{option}{whether to use the fast or slow method.}
13
+
14
+\item{x}{matrix with variables as columns.}
15
+}
16
+\value{
17
+CrossValParams object
18
+}
19
+\description{
20
+A function to perform fast cox proportional hazard model tests
21
+}
22
+\examples{
23
+data(asthma)
24
+time <- ppois(nrow(measurements),100)
25
+status <- sample(c(0,1), nrow(measurements), replace = TRUE)
26
+x = measurements
27
+y = cbind(time, status)
28
+output <- colCoxTests(x, y, "fast")
29
+}