Euler to Axis-angles

//Matrix multiplication using Jama Library
//https://math.nist.gov/javanumerics/jama/
import Jama.*;

float[] eulerToAxisRotations(float roll, float pitch, float yaw) {
  double[][] a = {
    {1, 0, 0},
    {0, cos(roll), -sin(roll)},
    {0, sin(roll), cos(roll)}
  };
  double[][] b = {
    {cos(pitch), 0, sin(pitch)},
    {0, 1, 0},
    {-sin(pitch), 0, cos(pitch)}
  };
  double[][] c = {
    {cos(yaw), -sin(yaw), 0},
    {sin(yaw), cos(yaw), 0},
    {0, 0, 1}
  };

  Matrix rollMatrix = new Matrix(a);
  Matrix pitchMatrix = new Matrix(b);
  Matrix yawMatrix = new Matrix(c);

  Matrix rMatrix = rollMatrix.times(pitchMatrix).times(yawMatrix);

  float theta = acos((((float)rMatrix.get(0,0) + (float)rMatrix.get(1,1) + (float)rMatrix.get(2, 2)) - 1) / 2);
  float multi = 1 / (2 * sin(theta));

  float rx = multi * ((float)rMatrix.get(2,1) - (float)rMatrix.get(1,2)) * theta;
  float ry = multi * ((float)rMatrix.get(0,2) - (float)rMatrix.get(2,0)) * theta;
  float rz = multi * ((float)rMatrix.get(1,0) - (float)rMatrix.get(0,1)) * theta;

  float[] r = {rx, ry, rz};
  return r;
}