R/func_signal_transform.R

In SLEMI: Statistical Learning Based Estimation of Mutual Information

#'  Initial verification and transformation of input variable
#' 
#' Internal, auxiliary functions
#'
#' @param data is a data.frame
#' @param signal is a character that indicates columns of data that include the labels of input
#' @return A data.frame that is a copy of data provided with signal column transformed to factor class. 
#' If signal has been numeric initially, additional column is created "signal_RAW" that is an exact
#' copy of original column
#' @examples 
#' data=data_example1
#' data1=SLEMI:::func_signal_transform(data,"signal")
#' data$signal=as.character(data$signal)
#' data2=SLEMI:::func_signal_transform(data,"signal")
#' data$signal=as.numeric(data$signal)
#' data3=SLEMI:::func_signal_transform(data,"signal")
#' @keywords internal
func_signal_transform<-function(data,signal){
  signal_class=class(data[[signal]])
  
    if (signal_class=="integer") {
      data[[signal]]=as.numeric(data[[signal]])
      signal_class=class(data[[signal]])
    }

    if (signal_class=="logical") {
      data[[signal]]=as.numeric(data[[signal]])
      signal_class=class(data[[signal]])
    }

    if (signal_class=="numeric") {
      data[[paste(signal,"_RAW",sep="")]]=data[[signal]]
      data[[signal]]=factor(data[[signal]],levels=sort(unique(data[[signal]])))
    } else if (signal_class=="character") {
      tmp_signal_values=unique(data[[signal]])
      tmp_signal_values_num=as.numeric(tmp_signal_values)
    if (any(is.na(tmp_signal_values_num))){
      message("Warning message due to check for numeric values in signal. Resulting object discarded.")
      tmp_signal_values_num=stringr::str_match(tmp_signal_values,"[0-9.]+")
      if (any(is.na(tmp_signal_values_num))) {
        data[[signal]]=factor(data[[signal]])
      } else {
        data[[signal]]=as.numeric(stringr::str_match(data[[signal]],"[0-9.]+"))
        data[[paste(signal,"_RAW",sep="")]]=data[[signal]]
        data[[signal]]=factor(data[[signal]],levels=sort(unique(data[[signal]])))
      }
    } else {
      data[[signal]]=factor(as.numeric(data[[signal]]),levels=sort(unique(as.numeric(data[[signal]]) ))) 
    } 
  } else if (signal_class=="factor"){

    tmp_signal_values=unique(as.character(data[[signal]]))
    tmp_signal_values_num=as.numeric(tmp_signal_values)
    if (any(is.na(tmp_signal_values_num))){
      message("Warning message due to check for numeric values in signal. Resulting object discarded.")
      tmp_signal_values_num=stringr::str_match(tmp_signal_values,"[0-9.]+")
      if (!any(is.na(tmp_signal_values_num))) {
        data[[signal]]=as.numeric(stringr::str_match(as.character(data[[signal]]),"[0-9.]+"))
        data[[paste(signal,"_RAW",sep="")]]=data[[signal]]
        data[[signal]]=factor(data[[signal]],levels=sort(unique(data[[signal]])))
      }
    } else {
      data[[paste(signal,"_RAW",sep="")]]=as.numeric(as.character(data[[signal]]))
      data[[signal]]=factor(as.numeric(as.character(data[[signal]])),levels=sort(unique(as.numeric(as.character(data[[signal]])) ))) 
    } 

  } else {
    stop(paste0('Input/signal is of type ',signal_class,'. It must be numeric, character or factor.'))
  }

  data
}