Converts a number to a negative base (between -2 and -10). Negadecimal, for example, or negabinary. http://en.wikipedia.org/wiki/Negative_base

toNegativeBase

function toNegativeBase(number, radix) {
    if (radix > -2 || radix < -10) { 
        throw 'invalid radix'; 
    }
    
    var result = 0;

    while (number != 0) { 
        var exp = number > 0 ? 0 : 1;
        var sum = 0;
        while (Math.abs(sum) < Math.abs(number)) {  
            sum += (-radix-1) * Math.pow(radix, exp); 
            exp += 2;
        }
        exp -= 2;
        var digit = Math.floor(number/Math.pow(radix, exp));
        digit = digit ? digit : 1;

        number -= digit * Math.pow(radix, exp);
        result += digit * Math.pow(10, exp); 
    }
    return result; 
}