R/oneway.R

In NaraaAltai/oneway: One-way Analysis of Variance

#' One Way Analysis of Variance
#'
#' oneway computes a one-way analysis of variance
#' and includes group level summary statistics.
#'
#' @param formula an object of a class formula, relating the
#' dependent variable to the grouping variable.
#' @param data a data frame containing variables in the model.
#'
#' @import dplyr
#' @export
#'
#' @return a list with 2 elements.
#' @examples
#' mileage <- oneway(mpg ~ cyl, mtcars)
oneway <- function(formula, data){
  # delete missing data
  data<- na.omit(data)

  # anova
  fit <- lm(formula, data)

  # summary stats
  group<- as.character(formula[[3]])
  y<-as.character(formula[[2]])

  stats <- data %>%
              group_by(.data[[group]]) %>%
              summarise(n=n(),
                  mean = mean(.data[[y]]),
                  sd = sd(.data[[y]])) %>%
              as.data.frame()


  # return results
  result <- list(anova=fit, summarystats = stats)
  class(result) <- "oneway"
  return(result)
}