index.html

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<!-- #  John Wiley & Sons, Inc.                                                                                                   # -->
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<!-- #  Book:   Algorithms in Bioinformatics: Theory and Implementation                                                           # -->
<!-- #  Author: Dr. Paul A. Gagniuc                                                                                               # -->
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<!-- #  Institution:                                                                                                              # -->
<!-- #    University Politehnica of Bucharest                                                                                     # -->
<!-- #    Faculty of Engineering in Foreign Languages                                                                             # -->
<!-- #    Department of Engineering in Foreign Languages                                                                          # -->
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<!-- #  Area:   European Union                                                                                                    # -->
<!-- #  Date:   04/01/2021                                                                                                        # -->
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<!-- #  Cite this work as:                                                                                                        # -->
<!-- #    Paul A. Gagniuc. Algorithms in Bioinformatics: Theory and Implementation. John Wiley & Sons, 2021, ISBN: 9781119697961. # -->
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<canvas id="bio" height="500" width="500"></canvas>

<script>

var z = 'GTAAAAATCTAGTTTTCCGTACTCTGTCCCCTTTTTAATCCTTCTCTGAATGGGTGTCC' +
        'TTGATTCACTGACATTTCCTAATTAACCAAGTTCTGCCAAGTTTCACATGAAACTTGGG' +
        'GAACCGATTTCATTCCCCCAGTATCACCCTGTGGCGCCACCTTCCGGAGCTGTGAGGAA' +
        'ACTCCGGACTTCCCCCCAACACCGCCCCCTCCCTCCACCCTCGGTCTCCGCTTTCTGCG' +
        'CTCTGCCGCGTTGGTTTTCGGAGGTGTCTGGGCGCATGCGCTTTGGACGGGCCGCCTAG' +
        'CCTAGGAGAGACTACAATTCCCAGAAGACAGTGCGAAAGAAAAAAAAAATCCCGCGGTC' +
        'CGTGGGGGTGGGAGAAATAAACGCTCGCGAGAGAACGAGGTTCAGGCGGCTGCACGAAG' +
        'GGGGTGGAGGGGGGCTGGAGAGAGTGAGGAGGAAGGGGAGGAGGTGCCGTCCCACAATA' +
        'CCAGGCGGGAGGGCGGGTAGGCGGTTTGTATCCGGGCTGTGAGGTGCTCGGAGCCTCGG' +
        'CGGACCTTGCTGCCTCTGTCTCTTTAACGCGAGAGGAAGCGATGCAGAGGGGTGGAAAA' +
        'TGGCAGAGCT';

Pattern(z);

function Pattern(s) {

    var n = 30;
    var sp = 1;
    var sw;

    var x;
    var y;

    var canvas = document.getElementById('bio');

    var w = canvas.width;
    var h = canvas.height;
    
    if (canvas.getContext) {

        var ctx = canvas.getContext('2d');

        ctx.clearRect(0, 0, canvas.width, canvas.height);
        ctx.fillStyle = 'black';

        for (var u=0; u<=s.length - n; u += sp)
        {
            sw = s.substr(u,n);
            
            x = (w/100) * CG(sw);
            y = (h/100) * IC(sw);
            
            ctx.fillRect(x, y, (w/sw.length)-2, 1);
        }
    }
}

// Information content
function IC(s)
{
    var t = 0;
    var m = 0;
    var x = [];
    
    x = s.split('');

    for (var u=1; u<=(s.length - 1); u++)
    {
        for (var i=0; i<=(s.length-u); i++)
        {m += f(x[i], x[u+i]);} 

        t += (m / (s.length-u) * 100);
        m = 0;
    }

    return (100 - (t / (s.length - 1))).toFixed(2);
}

function f(x1, x2){
    if (x1 == x2) {return 1;} else {return 0;}
}

// CG% content
function CG(s)
{
    s = s.toLowerCase();

    var a = 0;
    var t = 0;
    var c = 0;
    var g = 0;

    for (var u=0; u<=s.length; u ++)
    {
        var n = s.substr(u,1);

        if (n == "a") {a = a + 1;}
        if (n == "t") {t = t + 1;}
        if (n == "g") {g = g + 1;}
        if (n == "c") {c = c + 1;}
    }

    return ((100 / (c + g + t + a)) * (c + g)).toFixed(2);
}

</script>