R/fake_df.R

In jasonhilton/ggfan: Summarise a Distribution Through Coloured Intervals

#' Fake dataset intended to resemble a set of MCMC samples of a variable over
#' one covariate (perhaps time),
#'
#' The code needed to recreate the dataset is included in the examples
#'
#'
#' @format A data frame with 50000 rows and 3 columns
#' \describe{
#'  \item{x}{Values of the covariate}
#'  \item{y}{Values of the modelled quantity}
#'  \item{Sim}{Index referring to a MCMC posterior sample}
#' }
#'
#' @examples
#' # generate mean and variance for sequence of samples over time
#' library(magrittr)
#' library(tidyr)
#' set.seed(234)
#' N_time <- 50
#' N_sims <- 1000
#' time <- 1:N_time
#' mu <- time**2 * 0.03 + time * 0.3
#' sds <- exp(time**2 * -0.001 + time * 0.1)
#'
#' # simulate 1000 samples from each time point
#' fake_data <- sapply(time, function(i) rnorm(N_sims, mu[i], sds[i]))
#'
#' # gather into a long-form, tidy dataset
#' fake_df <- data.frame(x=time, t(fake_data)) %>%
#' tidyr::gather(key=Sim, value=y, -x)
#' # devtools::use_data(fake_df)
#'
"fake_df"