Class: Primegrid::MatrixPrinter

Inherits:
Object
  • Object
show all
Defined in:
lib/primegrid/matrix_printer.rb

Constant Summary collapse

@@gutter_width =

Prints out an un-rolled matrix to $stdout

Example:

>> MatrixPrinter.print([1, 0, 0, 0, 1, 0, 0, 0, 1], 3)
=> 1 0 0
=> 0 1 0
=> 0 0 1

Arguments:

array: the unrolled matrix
width: the number of columns in the matrix
opts : a hash containing optional arrays for row and column headers 
       e.g. { :col_header => [0, 1, 2], :row_header => [0, 1, 2] }

2
@@h_border_char = 
"-"
@@v_border_char = 
"|"

Class Method Summary collapse

Class Method Details

.build_matrix(array, width, opts = {}) ⇒ Object 



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# File 'lib/primegrid/matrix_printer.rb', line 28

def self.build_matrix(array, width, opts={})
  if array.length == 0 then return "" end

  padding = self.maxlen_in array
  gutter = " " * @@gutter_width
  has_header = opts.has_key? :col_header
  has_row_header = opts.has_key? :row_header
  buf = []
  
  # Add an optional header row
  if has_header
    header_sep = "-"
    padding = [padding, self.maxlen_in(opts[:col_header])].max
    header_str = opts[:col_header].map{|h| h.to_s.rjust(padding)}.join(gutter)
    buf.push "#{header_str}"
    buf.push "#{@@h_border_char * header_str.length}"
  end

  # Build the body of the matrix
  line = ""
  array.each_with_index do |p, i|
    line = "#{line}#{p.to_s.rjust(padding)}#{gutter}"
    if (i+1) % width == 0
      buf.push "#{line.rstrip}"
      line = ""
    end
  end

  # Add row headers
  if has_row_header
    padding = self.maxlen_in(opts[:row_header])
    padded_headers = opts[:row_header].map{|r| r.to_s.rjust(padding)}
    offset = 0
    if has_header
      offset = 2
      buf[0] = "#{' ' * (padding+1)}#{buf[0]}"
      buf[1] = "#{' ' * (padding+1)}#{buf[1]}"
    end

    padded_headers.each_with_index do |r, i|
      if i + offset < buf.length
        buf[i + offset] = "#{r}#{@@v_border_char}#{buf[i + offset]}"
      end
    end
  end

  return buf.join("\n")
end

.maxlen_in(array) ⇒ Object 



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# File 'lib/primegrid/matrix_printer.rb', line 77

def self.maxlen_in(array)
  as_lengths = array.map {|x| x.to_s.length}
  return as_lengths.max
end

.print(array, width, opts = {}) ⇒ Object 



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# File 'lib/primegrid/matrix_printer.rb', line 21

def self.print(array, width, opts={})
  matrix = self.build_matrix(array, width, opts)
  if !matrix.empty?
    $stdout.puts matrix
  end
end