Update conversion functions

[felix-hof]

This PR contains the following changes:

• replaces Vectorize() by vapply() in all functions defined in R/conversionHelpers.R. The advantages of this procedure are:
  • Massive speedups for large vectors of p/z-values
  • Keeps the format, i.e. converting a matrix of p-values to z-values with a given alternative returns a matrix as well. If length(alternative) > 1 the function returns an array with an additional dimension. Before, the function just returned a 1D vector
• Fixed behaviour in an edge case of ci2z
  • In expression z <- estimate / se we did not check whether se == 0. This led to z-values of Inf or -Inf. Now, this throws an error.
• Moved input checks to their own functions. This throws more informative error messages than stopifnot(). For future work, this might also help to avoid double argument checking in other functions.

[felix-hof]

This PR contains the following changes:

• replaces Vectorize() by vapply() in all functions defined in R/conversionHelpers.R. The advantages of this procedure are:
  • Massive speedups for large vectors of p/z-values
  • Keeps the format, i.e. converting a matrix of p-values to z-values with a given alternative returns a matrix as well. If length(alternative) > 1 the function returns an array with an additional dimension. Before, the function just returned a 1D vector
• Fixed behaviour in an edge case of ci2z
  • In expression z <- estimate / se we did not check whether se == 0. This led to z-values of Inf or -Inf. Now, this throws an error.
• Moved input checks to their own functions. This throws more informative error messages than stopifnot(). For future work, this might also help to avoid double argument checking in other functions.
• Updated references