CODEWITHSUNDEEP
javascriptoptimizationprototype
user1411443
user1411443

Reputation:

can this function get any faster in performance?

the function already tells you what it does, but anyway, it wraps angle and makes sure it's between 0-360. it's Javascript:

Number.prototype.wrapAngle = function(){
    var d = this;
    while(d > 360){ d -= 360;};
    while(d < 0){ d += 360;};
    return d.toString();
}

I need 'wrapAngle' to be fastest possible!

Upvotes: 0

Views: 60

Answers (2)

Alex Wayne
Alex Wayne

Reputation: 187222

Why not use modulo?

-721 % 360; // -1
390  % 360; // 30
90   % 360; // 90

So:

Number.prototype.wrapAngle = function(){
    var d = this % 360;
    if (d < 0) { // ensure positive number.
      d += 360;
    }

    // return a number, not a string.
    // This is a math based transformation of a number, so it should be a number.
    return d; 
}

Since modulus can return a negative number, but that number is always closer to zero than -360 you can simply increment it once if it's negative.

Performance comparison: http://jsperf.com/wrapangle

Upvotes: 3

Barmar
Barmar

Reputation: 782107

Use the modulus operator.

Number.prototype.wrapAngle = function(){
    return (this % 360).toString();
}

Upvotes: 1

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