R/internal.R

In utiml: Utilities for Multi-Label Learning

# Conditional value selection
#
# @param test an object which can be coerced to logical mode.
# @param yes object that will be returned when the test value is true.
# @param no object that will be returned when the test value is false
# @return The respective value yes or no based on test value. This is an
# alternative way to use a single logical value for avoid the real if/else for
# choice lists, matrices and other composed data.
#
# @examples
# \dontrun{
# utiml_ifelse(TRUE, dataframe1, dataframe2) ## dataframe1
# utiml_ifelse(length(my.list) > 10, my.list[1:10], my.list)
# }
utiml_ifelse <- function(test, yes, no) {
  list(yes, no)[c(test, !test)][[1]]
}

# Select the suitable method lapply or mclaplly
#
# @param mylist a list to iterate.
# @param myfnc The function to be applied to each element of the mylist.
# @param utiml.cores The number of cores to use. If 1 use lapply otherwise use
#    mclapply.
# @param utiml.seed A numeric value to set a seed to execute in parallel mode.
# @param ... Extra arguments to myfnc.
# @return A list with the results of the specified method.
utiml_lapply <- function(mylist, myfnc, utiml.cores, utiml.seed = NA, ...) {
  mylist <- as.list(mylist)
  indexes <- seq_along(mylist)
  names(indexes) <- names(mylist)

  thefunc <- function (i, ...) {
    myfnc(mylist[[i]], ...)
  }

  if (is.null(utiml.seed)) {
    utiml.seed = NA
  }

  if (utiml.cores > 1 && requireNamespace("parallel", quietly = TRUE)) {
    if (!is.na(utiml.seed)) {
      RNGkind("L'Ecuyer-CMRG")
      set.seed(utiml.seed)
    }

    result <- parallel::mclapply(indexes,
                           thefunc,
                           mc.cores = min(utiml.cores, length(mylist)),
                           mc.set.seed = TRUE,
                           ...)

    if (!is.na(utiml.seed)) {
      RNGkind("default")
    }
  }
  else {
    if (!is.na(utiml.seed)) {
      set.seed(utiml.seed)
    }
    result <- lapply(indexes, thefunc, ...)
  }

  result
}

# Internal normalize data function
#
# @param data a set of numbers.
# @param max.val The maximum value to normalize. If NULL use the max value
#   present in the data. (default: \code{NULL})
# @param min.val The minimum value to normalize. If NULL use the min value
#   present in the data (default: \code{NULL})
# @return The normalized data
#
# @examples
# \dontrun{
# utiml_normalize(c(1,2,3,4,5))
# #--> 0 0.25 0.5 0.75 1
#
# utiml_normalize(c(1,2,3,4,5), 10, 0)
# #--> 0.1 0.2 0.3 0.4 0.5
# }
utiml_normalize <- function(data, max.val = NULL, min.val = NULL) {
  max.val <- ifelse(is.null(max.val), max(data, na.rm = TRUE), max.val)
  min.val <- ifelse(is.null(min.val), min(data, na.rm = TRUE), min.val)
  utiml_ifelse(max.val == min.val, data, (data - min.val)/(max.val - min.val))
}

# Return the newdata to a data.frame or matrix
#
# @param newdata The data.frame or mldr data
# @return A dataframe or matrix containing only dataset
#
# @examples
# \dontrun{
# test <- emotions$dataset[,emotions$attributesIndexes]
# all(test == utiml_newdata(emotions)) # TRUE
# all(test == utiml_newdata(test)) # TRUE
# }
utiml_newdata <- function(newdata) {
  UseMethod("utiml_newdata")
}

# @describeIn utiml_newdata Return the data in the original format
utiml_newdata.default <- function(newdata) {
  newdata
}

# @describeIn utiml_newdata Return the dataset from the mldr dataset
utiml_newdata.mldr <- function(newdata) {
  newdata$dataset[newdata$attributesIndexes]
}

# Rename the list using the names values or its own content
#
# @param X A list
# @param names The list names, If empty the content of X is used
# @return A list with the new names
#
# @examples
# utiml_rename(c("a", "b", "c"))
# ## c(a="a", b="b", c="c")
#
# utiml_rename(c(1, 2, 3), c("a", "b", "c"))
# ## c(a=1, b=2, c=3)
utiml_rename <- function (X, names = NULL) {
  names(X) <- utiml_ifelse(is.null(names), X, names)
  X
}

# Define if two sets are equals independently of the order of the elements
#
# @param a A list
# @param b Other list
# @return Logical value where TRUE the sets are equals and FALSE otherwise.
# @examples
# \dontrun{
# utiml_is_equal_sets(c(1, 2, 3), c(3, 2, 1))
# ## TRUE
#
# utiml_is_equal_sets(c(1, 2, 3), c(1, 2, 3, 4))
# ## FALSE
# }
utiml_is_equal_sets <- function (a, b) {
  length(setdiff(union(a, b), intersect(a, b))) == 0
}