 
 // Updates the swing for each vertex, as described in the Force Atlas 2 paper.
 __device__ void fa2UpdateSwing(unsigned int gid, unsigned int numvertices,
-    float* forceX, float* forceY, float* oldForceX, float* oldForceY,
+    float forceX, float forceY, float* oldForceX, float* oldForceY,
     float* swg)
 {
   if (gid < numvertices)
   {
-    float fx = forceX[gid];
-    float fy = forceY[gid];
+    float fx = forceX;
+    float fy = forceY;
     vectorSubtract(&fx, &fy, oldForceX[gid], oldForceY[gid]);
     float vlen = vectorGetLength(fx, fy);
     swg[gid] = vlen;

  unsigned int gid = threadIdx.x + (blockIdx.x * BLOCK_SIZE);
  float graphSpeed = *oldGraphSpeed;

  // Update speed of Graph.
  fa2UpdateSpeedGraph(*graphSwing, *graphTract, &graphSpeed);


  {
    vxLocs[gid] += xdisp[gid];
    vyLocs[gid] += ydisp[gid];
  }
}

