R/minNonzero.R

In ejanalysis/analyze.stuff: Miscellaneous Tools for Analyzing Data in Rows and Columns

#' @title Find minimum non-zero number(s) - BUT EXCLUDES COLUMNS THAT ARE NOT NUMERIC OR ARE FACTOR**
#'
#' @description
#' Returns minimum nonzero numbers in vector, matrix, or data.frame
#'
#' @param mydf Required. Must be vector, matrix, or data.frame
#' @return A number or vector of numbers
#' @examples
#' minNonzero(-1:6)
#' minNonzero(data.frame(a=0:10, b=1:11, c=c(0,1:9,NA), d='text', stringsAsFactors = FALSE))
#' minNonzero(data.frame(a=0:10, b=1:11, c=c(0,1:9,NA), d='3', stringsAsFactors = TRUE))
#' @export
minNonzero <- function(mydf) {

  if (is.data.frame(mydf)) {
    return(
      sapply(
        mydf[ , sapply(mydf, mode)=='numeric' & !sapply(mydf, is.factor)],
        function(x) {
          zero <- (!x)
          ifelse(all(zero) || all(is.na(x)), NA, min(x[!zero],  na.rm=TRUE))
        }
      )
    )
  }

  if (is.matrix(mydf)) {
    return(
      apply(
        mydf[ , apply(mydf, 2, mode)=='numeric' & !apply(mydf, 2, is.factor)],
        2,
        function(x) {
          zero <- (!x)
          ifelse(all(zero) || all(is.na(x)), NA, min(x[!zero],  na.rm=TRUE))
        }
      )
    )
  }

  if (is.vector(mydf)) {
    if (!is.numeric(mydf) | is.factor(mydf)) {stop('must be numeric and not factor')}
    zero <- (!mydf)
    return( ifelse(all(zero) || all(is.na(mydf)), NA, min(mydf[!zero],  na.rm=TRUE)) )
  }

  stop('must be vector, matrix, or data.frame')
}