/**
* examines solute grid to determine where to move based on attraction/repulsion to/from a solute
*/
private void chemotax() {
// 1) get the gradient--this will be the direction the particle
// should move in or away from
ContinuousVector direction = chemotaxSolute.getGradient2DNoZ(_location);
if (repellent) {
direction.turnAround();
}
// 2) scale the gradient set the scaled gradient as _movement
_movement = this.getScaledMove(_location, direction, distEachRun);
}
