Letter histogram

letter_stats.rb

def letter_stats(string)
  string.gsub!(/[^A-z]/, '').upcase!
  letters = {}
  string.split('').each do |letter|
    if letters[letter].nil?
      letters[letter] = { sightings: 1,
                          frequency: (1.to_f / string.size.to_f * 100).ceil }
    else
      letters[letter][:sightings] += 1
      letters[letter][:frequency] = (letters[letter][:sightings].to_f / string.size.to_f * 100).ceil
    end
  end
  letters.sort
end

string = "THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG THIS IS AN EXAMPLE OF HOW TO TEST YOUR HISTOGRAM PROGRAM. YOU CAN USE THIS EXAMPLE."
data = letter_stats(string)
data.each do |k, v|
  puts "#{k} - #{v[:sightings]}, (#{v[:frequency]}%)"
end
# >> A - 7, (7%)
# >> B - 1, (1%)
# >> C - 2, (2%)
# >> D - 1, (1%)
# >> E - 9, (9%)
# >> F - 2, (2%)
# >> G - 3, (3%)
# >> H - 6, (6%)
# >> I - 5, (5%)
# >> J - 1, (1%)
# >> K - 1, (1%)
# >> L - 3, (3%)
# >> M - 5, (5%)
# >> N - 3, (3%)
# >> O - 11, (11%)
# >> P - 4, (4%)
# >> Q - 1, (1%)
# >> R - 6, (6%)
# >> S - 7, (7%)
# >> T - 8, (8%)
# >> U - 5, (5%)
# >> V - 1, (1%)
# >> W - 2, (2%)
# >> X - 3, (3%)
# >> Y - 3, (3%)
# >> Z - 1, (1%)

letters.php

<?php

	function countLetters($str)
	{
		$str = preg_replace('/[^A-z]/', '', $str);
		$str = strtoupper($str);
		$total = strlen($str);
		$letters = array();
		
		for ($i=0; $i < strlen($str); $i++)
		{ 
			$letters[$i] = $str{$i};
		}
		
		$histogram = array();
		foreach ($letters as $letter)
		{
			if (isset($histogram[$letter])) 
				$histogram[$letter]++;
			else
				$histogram[$letter] = 1;
		}
		
		$data = array();
		
		foreach ($histogram as $letter => $sightings)
		{
			$data[$letter] = array('sightings' => $sightings, 'frequency' => round($sightings / $total * 100));
		}
		ksort($data);
		return $data;

	}

	$str = 'THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG THIS IS AN EXAMPLE OF HOW TO TEST YOUR HISTOGRAM PROGRAM. YOU CAN USE THIS EXAMPLE.';

	$data = countLetters($str);
	
	foreach ($data as $key => $value)
	{
		echo "The letter $key was found {$value['sightings']} times, which is a frequency of {$value['frequency']}%\n";
	}
?>