Coleman-Liau function

colemanLiau.js

function colemanLiau(counts) {
    var LETTER_WEIGHT = 0.0588;
    var SENTENCE_WEIGHT = 0.296;
    var BASE = 15.8;
    var PERCENTAGE = 100;
  
    if (!counts || !counts.sentence || !counts.word || !counts.letter) {
        return NaN;
    }

    return LETTER_WEIGHT * (counts.letter / counts.word * PERCENTAGE) -
        SENTENCE_WEIGHT * (counts.sentence / counts.word * PERCENTAGE) -
        BASE;
}

demo.js

colemanLiau({'sentence': 5,'word': 119,'letter': 639});