# Logarithmic spiral appears inverted

I'm learning to code the equation for a logarithmic spiral for a graphics visualization. However, it appears to be inverted with the radius getting smaller (rather than larger) toward the outside of the curve. How can I invert the result so the radius gets larger as the curve moves outward?

var theta = 1; // begin at theta 1
for (var p = 0; p < particleCount; p++) {
// LOG SPIRAL SHAPE
var a = 500; // a constant
var b = 0.2; // another constant
var pX = a * Math.cos(theta) * Math.log(b * theta);
var pY = a * Math.sin(theta) * Math.log(b * theta);
theta += 1; // increment theta
// place an image at pX,pY and repeat


Since a picture is worth a thousand words (or lines of code), here is the result: • Well, where is your problem? Note the outer "particles" are the ones generated last, but the logarithm grows very slowly. This is why the points are more dense at the outside. And you'll probably want to ensure not to have a negative radius, thus $b\theta \ge 1$ is required.  Also, the logarithmic spiral, as you can see from the article, needs $\cos \theta \cdot \exp(b\cdot\theta)$, not $\cos(\theta)\cdot \log(b\theta)$ Jul 23, 2014 at 18:46
• Also, if you want your spiral to look better, I suspect you should multiply theta by $\pi/180$ before feeding it to the sin and cos functions. Computer trig functions typically assume that the argument is in radians. Jul 23, 2014 at 18:48

Replace Math.log(b * theta) by Math.exp(b * theta) and things should agree with the formulas from the article you referenced.