class NMatrix

# File lib/nmatrix/rowcol.rb, line 27
def column(col_number, get_by = :copy)
  if dim > 1 && col_numbers = get_row_or_col_index_array(col_number)
    out = NMatrix.new [rows, col_numbers.length], default_value, dtype: dtype, stype: stype

    col_numbers.each_with_index do |colnum, i|
      out[0..-1, i] = self[0..-1, colnum]
    end

    out
  else
    internal_column(col_number, get_by)
  end
end

# File lib/nmatrix/rowcol.rb, line 7
def row(row_number, get_by = :copy)
  if row_numbers = get_row_or_col_index_array(row_number)
    out = NMatrix.new [row_numbers.length, cols].compact, default_value, dtype: dtype, stype: stype

    row_numbers.each_with_index do |rownum, i|
      if dim > 1
        out[i, 0..-1] = self[rownum, 0..-1]
      else
        out[i] = self[rownum]
      end
    end

    out
  else
    internal_row(row_number, get_by)
  end
end

# File lib/nmatrix/rowcol.rb, line 52
def booleans_to_indexes row_numbers
  row_numbers.map.with_index {|v, i| i if v}.compact
end

# File lib/nmatrix/rowcol.rb, line 45
def get_row_or_col_index_array arg
  return unless arg.is_a?(Array) || arg.is_a?(NMatrix)
  out = arg.to_a.flatten
  out = booleans_to_indexes(out) unless out.first.is_a?(Integer)
  out
end