R/TDASample.R

In mrdwab/TDAtools: A collection of functions written for students at the Tata-Dhan Academy

#'Use an alphanumeric string as the seed to generate a random sample
#'
#'Use this function to generate a reproducible random sample. Random samples
#'are usually made reproducible by setting a numeric seed with
#'\code{\link{set.seed}}. This function does some transformations to a given
#'alphanumeric string before compting a seed and drawing a sample based on that
#'seed.
#'
#'
#'@param inString The alphanumeric string that you want to use for generating
#'your seed
#'@param N The total population you are sampling from
#'@param n The number of samples you need
#'@return Returns a \code{\link{list}} with the class \code{TDASample} to
#'handle the formatting of the output.  The list items include: \itemize{ \item
#'\code{Metadata} A character vector of length = 4 containing the date the
#'sample was drawn, the input string that was used, the population size, and
#'the desired sample size. \item \code{SeedUsed} The seed that was
#'automatically generated by the function. \item \code{FinalSample} The final
#'result of running \code{set.seed(SeedUsed); sample(--input parameters--)}
#'\item \code{FinalSample_sorted} As above, but sorted }
#'@note The \code{inString} argument is \emph{not} case-sensitive, but it is
#'"space-sensitive". That is to say, \code{inString = "Ananda Mahto"} will
#'result in the same seed as \code{inString = "ananda mahto"}, but a different
#'seed from \code{inString = "anandamahto"} or \code{inString = " Ananda Mahto
#'"} \emph{(note the extra spaces before and after the names)}.
#'
#'For a more robust conversion from alphanumeric strings to seeds before
#'sampling, the
#'\code{\link[mrdwabmisc:stringseed.sampling]{stringseed.sampling}} function
#'from the "mrdwabmisc" package is recommended.
#'@author Ananda Mahto
#'@seealso \code{\link{sample}}, \code{\link{set.seed}},
#'\code{\link[mrdwabmisc:stringseed.sampling]{stringseed.sampling}}
#'@examples
#'
#'TDASample(inString = "Ananda Mahto", N = 100, n = 20)
#'
#'## Should have given a seed of 142190
#'## Lets verify the sample manually
#'set.seed(142190)
#'sample(100, 20)
#'
#'TDASample("Some crazy! Text string with 123 numbers () in it$", 100, 20)
#'
TDASample <- function(inString, N, n) {
  seed <- SeedMe(inString)
  
  set.seed(seed)
  temp0 <- sample(N, n)
  
  temp1 <- list(
    Metadata = 
      c(sprintf("%s", Sys.time()),
                sprintf("%s", inString),
                sprintf("%d", N),
                sprintf("%d", n)),
    SeedUsed = seed, 
    FinalSample = temp0,
    FinalSample_sorted = sort(temp0))
  
  rm(.Random.seed, envir=globalenv())
  
  class(temp1) <- c("TDASample", class(temp1))
  temp1
}