R/ggtestinfo_se_plotly.R

In m-a-siraji/BAAP: Create Publication Quality Tables and Plots

#' A Function for Creating  Item Response Theory based test information plot with standard error with plotly.
#'
#' This function will create Item Response Theory based Test information plot with standard error using ggplot2 and plotly from objects created from
#' mirt pack.
#' Using ggplot2 will enable the user to modify the Item plot.
#'
#' @param  dataframe your data.
#' @param  model A mirt package fitted object.
#'@examples
#'data <- tabledown::Rotter[, 11:31]
#'model <- mirt::mirt(data, model = 1, itemtype = '2PL')
#'plot <- ggtestinfo_se_ploty(data, model)
#'@return
#'A publication quality Test information plot with standard error (dashed line). Output object is a ggplot object.


#'@importFrom mirt extract.item iteminfo
#'
#'@importFrom plotly ggplotly

#' @export
ggtestinfo_se_ploty <- function(dataframe,model){
  Theta <- matrix(seq(-6,6, by = .1))
  T1 <- 0
  se <- 0
  for(i in 1:ncol(dataframe)){
    T1 <- T1 + mirt::iteminfo(extract.item(model, i), Theta)
    se <- 1/(sqrt(T1))

  }

  data <- as.data.frame(cbind(Theta, T1, se))
  p1 <-  ggplot2::ggplot(data, ggplot2::aes(x=Theta, y=T1)) +
    ggplot2::geom_line() + ggplot2::labs(y="Test Information")+
    geom_line(data = data,linetype = "dashed",color = "red", ggplot2::aes(x=Theta, y=se))

  p2 <- plotly::ggplotly(p1)
  return(p2)
}