Module: R::IndexedObject

Included in:
DataFrame, Environment, Language, List, Object, Vector
Defined in:
lib/R_interface/rindexed_object.rb

Overview

Instance Method Summary collapse

Instance Method Details

#[](*index) ⇒ Object

subset a vector with an index

Parameters:

  • index (Array) —

    The vector index.



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# File 'lib/R_interface/rindexed_object.rb', line 37

def [](*index)
  # dealing with double indexing function '[['
  # If we have multiple indices, or a single array index, use [[ or `[` for names
  if (index.size > 1) || (index[0].is_a? Array)
    args = (index.size > 1) ? index : index[0]
    # For DataFrame with two indices: R's [[i,j]] is row i, col j. R's [[ does not accept character indices; use `[` for row/col names.
    # When any index is :all, use `[` (single bracket) so R gets m[i,] or m[,j]; `[[` does not accept missing subscript.
    # When any index is an R object (e.g. vector), use `[`; `[[` only selects one element ("attempt to select more than one element").
    use_md = (args.size == 2 && self.is_a?(::R::DataFrame) && (args[0].is_a?(::String) || args[0].is_a?(::Symbol) || args[1].is_a?(::String) || args[1].is_a?(::Symbol))) ||
             (args.size == 2 && (args[0] == :all || args[1] == :all)) ||
             (args.size == 2 && (args[0].is_a?(::R::Object) || args[1].is_a?(::R::Object)))
    if use_md
      ::R::Support.exec_function(::R::Support.md_index, self, *args)
    else
      ::R::Support.exec_function(::R::Support.dbk_index, self, *args)
    end
  else
    if self.is_a?(::R::DataFrame) && index.size == 1 &&
       (index[0].is_a?(::R::Language) || index[0].is_a?(::R::Object))
      # For data.frame, a single logical/language index is expected to filter rows.
      # Evaluate language conditions in data-frame context, then subset df[cond, ].
      row_filter = index[0].is_a?(::R::Language) ? ::R::Support.exec_function("with", self, index[0]) : index[0]
      ::R::Support.exec_function(::R::Support.md_index, self, row_filter, :all)
    else
      ::R::Support.exec_function_name("`[`", self, *index)
    end
  end
rescue ::RuntimeError => e
  if e.message.to_s.include?("incorrect number of subscripts")
    ::Kernel.raise(::ArgumentError, e.message)
  end
  ::Kernel.raise(e)
end

#[]=(*args) ⇒ Object

subset assign a vector with an index to a value index can span multiple values, for ex., R.c(2, 3, 5)

Parameters:

  • index (Array) —

    The vector index

  • values (R::Object) —

    The values to assign to the index. Note that



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# File 'lib/R_interface/rindexed_object.rb', line 79

def []=(*args)
  values = args.pop
  index = args

  # Assign result back to same handle so the object is updated in place (R's x[i] <- v semantics)
  if (index.size > 1) || (index[0].is_a? Array)
    all_args = [@r_interop, *index, values].map { |a| ::R::Support.parse_arg(a) }.join(", ")
    ::R.bridge.eval_r("#{@r_interop} <- `[[<-`(#{all_args})")
  else
    idx_r = ::R::Support.parse_arg(index[0])
    vals_r = ::R::Support.parse_arg(values)
    ::R.bridge.eval_r("#{@r_interop} <- `[<-`(#{@r_interop}, #{idx_r}, #{vals_r})")
  end

  self
end

#size ⇒ Object 



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# File 'lib/R_interface/rindexed_object.rb', line 100

def size
  length.unboxed_get(0)
end