code: public static boolean cs_happly(Scs V, int i, float beta, float[] x) {
          int p, Vp[], Vi[];
          float Vx[], tau = 0;
          if (!Scs_util.CS_CSC(V) || x == null)
              return (false); /* check inputs */
          Vp = V.p;
          Vi = V.i;
          Vx = V.x;
          for (p = Vp[i]; p < Vp[i + 1]; p++) /* tau = v'*x */
          {
              tau += Vx[p] * x[Vi[p]];
          }
          tau *= beta; /* tau = beta*(v'*x) */
          for (p = Vp[i]; p < Vp[i + 1]; p++) /* x = x - v*tau */
          {
              x[Vi[p]] -= Vx[p] * tau;
          }
          return (true);
      }
docs: Applies a Householder reflection to a dense vector, x = (I -
  beta*v*v')*x.
  
  @param V
  column-compressed matrix of Householder vectors
  @param i
  v = V(:,i), the ith column of V
  @param beta
  scalar beta
  @param x
  vector x of size m
  @return true if successful, false on error