public void getPos(double t, double[] v) {
    final int n = mT.length;
    final int dim = mY[0].length;
    if (t <= mT[0]) {
      for (int j = 0; j < dim; j++) {
        v[j] = mY[0][j];
      }
      return;
    }
    if (t >= mT[n - 1]) {
      for (int j = 0; j < dim; j++) {
        v[j] = mY[n - 1][j];
      }
      return;
    }

    for (int i = 0; i < n - 1; i++) {
      if (t == mT[i]) {
        for (int j = 0; j < dim; j++) {
          v[j] = mY[i][j];
        }
      }
      if (t < mT[i + 1]) {
        double h = mT[i + 1] - mT[i];
        double x = (t - mT[i]) / h;
        for (int j = 0; j < dim; j++) {
          double y1 = mY[i][j];
          double y2 = mY[i + 1][j];

          v[j] = y1 * (1 - x) + y2 * x;
        }
        return;
      }
    }
  }
This performs a simple linear interpolation in multiple dimensions
ConstraintLayoutExamples/CycleEditor/src/com/google/androidstudio/motionlayoutcycles/LinearInterpolator.java