R/Shinyapp.R

In Rmfrac: Simulation and Statistical Analysis of Multifractional Processes

#' Shiny app to visualise and analyse processes
#'
#' @description
#' Launches a Shiny app to visualise and analyse realisations of Brownian motion (see \code{\link{Bm}}),
#' Brownian bridge (see \code{\link{Bbridge}}), fractional Brownian motion (see \code{\link{FBm}}),
#' fractional Brownian bridge (see \code{\link{FBbridge}}), fractional Gaussian noise (see \code{\link{FGn}}),
#' Gaussian Haar-based multifractional processes (see \code{\link{GHBMP}}) and user-provided time series data.
#'
#' @return An interactive Shiny app with the following user interface controls.
#'
#' **GHBMP simulation**
#' \describe{
#'   \item{\code{Hurst function}}{Input the Hurst function in terms of \code{t}.
#'   The default is set to \code{0.5 + 0*t}.}
#'   \item{\code{Time sequence}}{Input the time sequence which belongs to the interval \eqn{[0,1]}. The default is set to \code{seq(0, 1, by = (1/2)^10)}.}
#'   \item{\code{J}}{Input or select a positive integer. For large \code{J} could be rather time consuming. Default is set to 15.}}
#'**Hurst function and LFD estimation**
#'   \describe{
#'   \item{\code{Number of sub-intervals for estimation}}{Default is set to 100.}
#'   \item{\code{Q}}{Input or select an integer greater than or equal to 2. Default is set to 2.}
#'   \item{\code{L}}{Input or select an integer greater than or equal to 2. Default is set to 2.}
#'   \item{\code{Plot}}{Choose the required from: \code{Theoretical Hurst function}, \code{Raw estimate of Hurst function}, \code{Smoothed estimate of Hurst function}, \code{Raw estimate of Local Fractal Dimension}, \code{Smoothed estimate of Local Fractal Dimension}.}}
#' **Excursion set and area**
#'  \describe{
#'   \item{\code{Number of time steps}}{Input the number of steps the time interval needs to be split into.}
#'   \item{\code{Constant level}}{Input the constant level.}
#'   \item{\code{Compare to level}}{\code{Greater}, \code{Lower}.}
#'   \item{\code{Plot}}{Select: \code{Excursion set}, \code{Excursion area}.}}
#' **Longest streak**
#'  \describe{
#'   \item{\code{Longest streak to plot}}{Select: \code{Increasing}, \code{Decreasing}.}}
#' **Maximum and minimum**
#'  \describe{
#'   \item{\code{Plot}}{Select: \code{Maximum}, \code{Minimum}.}}
#' @importFrom shiny runApp
#' @importFrom shinycssloaders withSpinner
#' @details
#' For \code{Input time series}, provide a \code{.csv} file that has headers of its columns.
#' It must have two columns: the first column should contain the numeric time sequence \eqn{t},
#' and the second the corresponding time series values \eqn{X(t)}. To get reliable estimation
#' results for time series, it is recommended to use at least 500 time points.
#' Make sure there are no extra header rows or footnotes.
#'
#' @export shinyapp_sim
#'
#' @seealso \code{\link{Bm}}, \code{\link{FBm}}, \code{\link{FGn}}, \code{\link{Bbridge}}, \code{\link{FBbridge}},
#' \code{\link{GHBMP}}, \code{\link{Hurst}}, \code{\link{LFD}},  \code{\link{sojourn}},  \code{\link{exc_Area}}
#' \code{\link{long_streak}}, \code{\link{X_max}}, \code{\link{X_min}}
#'
#' @examples
#' if (interactive()) {
#'   shinyapp_sim()
#' }
#'
shinyapp_sim<- function() {
  appDir <- system.file("GHBMP_app", package = "Rmfrac")
  if (appDir == "") {
    stop("Could not find example directory. Try re-installing `Rmultifractional` package.", call. = FALSE)
  }

  runApp(appDir, display.mode = "normal")
}