function letterset = reduceFuzzyLetter(a,numeric)

if numeric
    switch a
        case 'A'
            letterset = [1];
        case 'C'
            letterset = [2];
        case 'G'
            letterset = [3];
        case 'T'
            letterset = [4];
        case 'R'
            letterset = [1 3];
        case 'Y'
            letterset = [2 4];
        case 'K'
            letterset = [3 4];
        case 'M'
            letterset = [1 2];
        case 'S'
            letterset = [2 3];
        case 'W'
            letterset = [1 4];
        case 'B'
            letterset = [2 3 4];
        case 'D'
            letterset = [1 3 4];
        case 'H'
            letterset = [1 2 4];
        case 'V'
            letterset = [1 2 3];
        case 'N'
            letterset = [1 2 3 4];
        otherwise 
            letterset = [];
    end
        

else
        switch a
        case 'A'
            letterset = 'A';
        case 'C'
            letterset = 'C';
        case 'G'
            letterset = 'G';
        case 'T'
            letterset = 'T';
        case 'R'
            letterset = 'AG';
        case 'Y'
            letterset = 'CT';
        case 'K'
            letterset = 'GT';
        case 'M'
            letterset = 'AC';
        case 'S'
            letterset = 'CG';
        case 'W'
            letterset = 'AT';
        case 'B'
            letterset = 'CGT';
        case 'D'
            letterset = 'AGT';
        case 'H'
            letterset = 'ACT';
        case 'V'
            letterset = 'ACG';
        case 'N'
            letterset = 'ACGT';
        otherwise 
            letterset = '';
    end
    
end