R/class-epoch.R

In raveio: File-System Toolbox for RAVE Project

#' Definition for epoch class
#' @description Trial epoch, contains the following information: \code{Block}
#' experiment block/session string; \code{Time} trial onset within that block;
#' \code{Trial} trial number; \code{Condition} trial condition. Other optional
#' columns are \code{Event_xxx} (starts with "Event"). See
#' \url{https://openwetware.org/wiki/RAVE:Epoching} or more details.
#' @examples
#'
#' # Please download DemoSubject ~700MB from
#' # https://github.com/beauchamplab/rave/releases/tag/v0.1.9-beta
#'
#' \dontrun{
#'
#' # Load meta/epoch_auditory_onset.csv from subject demo/DemoSubject
#' epoch <-RAVEEpoch$new(subject = 'demo/DemoSubject',
#'                       name = 'auditory_onset')
#'
#' # first several trials
#' head(epoch$table)
#'
#' # query specific trial
#' old_trial1 <- epoch$trial_at(1)
#'
#' # Create new trial or change existing trial
#' epoch$set_trial(Block = '008', Time = 10,
#'                 Trial = 1, Condition = 'AknownVmeant')
#' new_trial1 <- epoch$trial_at(1)
#'
#' # Compare new and old trial 1
#' rbind(old_trial1, new_trial1)
#'
#' # To get updated trial table, must update first
#' epoch$update_table()
#' head(epoch$table)
#'
#' }
#'
#' @export
RAVEEpoch <- R6::R6Class(
  classname = 'RAVEEpoch',
  lock_objects = FALSE,
  private = list(
    basic_columns = c("Block", "Time", "Trial", "Condition")
  ),
  public = list(

    #' @field name epoch name, character
    name = character(0),

    #' @field subject \code{RAVESubject} instance
    subject = NULL,

    #' @field data a list of trial information, internally used
    data = NULL,

    #' @field table trial epoch table
    table = NULL,

    #' @field .columns epoch column names, internally used
    .columns = character(0),

    #' @description constructor
    #' @param subject \code{RAVESubject} instance or character
    #' @param name character, make sure \code{"epoch_<name>.csv"} is in meta
    #' folder
    initialize = function(subject, name){
      stopifnot2(stringr::str_detect(name, '^[a-zA-Z0-9_]'),
                 msg = 'epoch name can only contain letters[a-zA-Z] digits[0-9] and underscore[_]')

      self$subject <- restore_subject_instance(subject)
      self$name <- name

      self$data <- dipsaus::fastmap2()

      if(name %in% self$subject$epoch_names){
        # load epoch
        table <- self$subject$meta_data('epoch', name)
        for(ii in seq_len(nrow(table))){
          row <- table[ii,]
          self$data[[as.character(row$Trial)]] <- row
        }

        self$.columns <- names(table)
        self$.columns <- self$.columns[!self$.columns %in% c(private$basic_columns, 'X')]
        self$.columns <- self$.columns[!stringr::str_detect(self$.columns, '^X\\.[0-9]+$')]
      }
      self$update_table()

    },

    #' @description get \code{ith} trial
    #' @param i trial number
    #' @param df whether to return as data frame or a list
    trial_at = function(i, df = TRUE){
      re <- as.list(self$data[[as.character(i)]])
      re <- sapply(self$columns, function(nm){
        re <- re[[nm]]
        if(!length(re) || is.na(re)){
          return(NA)
        }
        if(stringr::str_detect(nm, '^Event_.+$')){
          re <- as.numeric(re)
        }
        re
      }, simplify = FALSE, USE.NAMES = TRUE)
      if(df){
        re <- as.data.frame(re, stringsAsFactors = FALSE)
      }
      re
    },

    #' @description manually update table field
    #' @returns \code{self$table}
    update_table = function(){
      self$table <- do.call('rbind', lapply(self$trials, self$trial_at, df = TRUE))
      self$table
    },

    #' @description set one trial
    #' @param Block block string
    #' @param Time time in second
    #' @param Trial positive integer, trial number
    #' @param Condition character, trial condition
    #' @param ... other key-value pairs corresponding to other optional columns
    set_trial = function(Block, Time, Trial, Condition, ...){
      stopifnot2(Block %in% self$subject$blocks, msg = 'invalid block')
      self$data[[as.character(Trial)]] <- list(Block = Block, Time = Time, Trial = Trial, Condition = Condition, ...)
      names(list(...))
      more_cols <- setdiff(names(list(...)), self$.columns)
      if(length(more_cols)){
        self$.columns <- c(self$.columns, more_cols)
      }
      self$trial_at(Trial)
    }

  ),
  active = list(

    #' @field columns columns of trial table
    columns = function(){
      unique(c(private$basic_columns, self$.columns))
    },

    #' @field n_trials total number of trials
    n_trials = function(){
      length(self$data)
    },

    #' @field trials trial numbers
    trials = function(){
      sort(as.integer(names(self$data)))
    }
  )
)