R/plot_transition_matrix.R

In ryanjessop/ClickViz: Clickstream Visualisations

#' Plot transition heatmap
#'
#' Builds an interactive heatmap of the first order Markov chain transition matrix.
#'
#' @param data Clickstream data
#' @return Heatmap of the transition matrix
#' @examples
#' cls <- readClickstreams(file)
#' plot_transition_heatmap(cls)
plot_transition_heatmap <- function(data) {
  mc <- clickstream::fitMarkovChain(data)
  matrix <- t(as.matrix(mc@transitions[[1]]))

  plotly::plot_ly(
    x = colnames(matrix),
    y = colnames(matrix),
    z = matrix,
    colors = colorRampPalette(c("white", "yellow", "red", "dark red"))(100),
    colorbar = list(
      title = 'Transition \n Probability',
      titlefont = list(size = 20),
      tickfont = list(size = 20)
    ),
    type = "heatmap",
    zauto = FALSE,
    zmin = 0,
    zmax = max(matrix, na.rm = TRUE)
  ) %>%
    plotly::layout(
      xaxis = list(
        title = "To",
        titlefont = list(size = 30),
        tickfont = list(size = 20)
      ),
      yaxis = list(
        title = "From",
        titlefont = list(size = 30),
        tickfont = list(size = 20)
      )
    )
}