testo.js

/// BROKEN OUT FUNCTIONS


// Function replaces character in progress string if a match is found
// between the random string and the target string.

function setCharAt(str,index,chr) {
    if(index > str.length-1) return str;
    return str.substr(0,index) + chr + str.substr(index+1);
}

// Function creates a target string for each trial.

function createTargetString(){

        targetString="";

        for ( var n=0; n < targetLength; n++ ) {

            var rnum = Math.floor(Math.random() * possibleCharacters.length);
            targetString += possibleCharacters.substring(rnum,rnum+1);

            }
            return targetString;
}

// Function creates a random string to compare to the target string
// for each generation.

function createRandomString(){

        randomString = "";


        for ( var i=0; i < targetString.length; i++ ) {

            var rnum = Math.floor(Math.random() * possibleCharacters.length);
            randomString += possibleCharacters.substring(rnum,rnum+1);

            }

        return randomString;

}

// Function creates the progress string of empty characters

function createProgressString(){
    var progressString = "";

        for (var c=0; c < targetString.length; c++) {
            progressString = progressString + "*";
        }
    return progressString;
}

// Function loops through target string and compares each character
// to the random string.  Replaces character on progress string if match.

function loopCheckReplace(){

    for (var p = 0; p < targetString.length; p++) {

    var first_char = randomString.slice(p, p+1);

    var second_char = targetString.slice(p, p+1);

    if (first_char === second_char) {

        progressString = setCharAt(progressString, p, second_char);

        }

    }

}

// Function gets an average of the number of generations required for the trials
// to get from the progress string to the target string.

function getAverageGenerations(){

    var add = 0;

    for (var u = 0; u < generationsRequiredResults.length; u++){
        add = add + generationsRequiredResults[u];
    }

    return add / u;
}


// VARIABLES FOR EXPERIMENT

// Variable sets the number of characters for the strings to be tested.
// Begins at 2 and ends at maximum number.

var maximumStringLength = 10000;

// Variable sets the number of trials to generate an average number of
// generations to get to the target string.

var numberOfTrials = 10000;

// Variable sets the characters that are used to generate the target
// string and also the random string for each generation.

var possibleCharacters = " abcdefghiklmnopqrstuvwxyz";


// SCRIPT

// Loop begins experiments at a string of two characters and continues up
// to the maximum string length specified for the overall experiment.

for (var targetLength = 2; targetLength < maximumStringLength; targetLength++){

    targetString = createTargetString();

    var generationsRequiredResults = [];

    // This loop continues until the number of trials is complete.

    for (var r = 0; r < numberOfTrials; r++){

        var counter = 0;

        var progressString = createProgressString();

        // Trial Loop continues until progress string equals the target string.

        do {

        var counter = counter + 1;

        var randomString = createRandomString();

        loopCheckReplace();

        } while (targetString != progressString);

    generationsRequiredResults[r] = counter;

    }

    var averageGenerations = getAverageGenerations();

    // Prints the number of characters for target string and the average number
    // of generations required to get there for that number of characters.
    // Prints out from server logs so it's easy to copy and paste to *.csv file.

    console.log(targetLength + ", " + averageGenerations);

}