code: def DSYR_blas(A, x, alpha=1.):
      
      At = blas.dsyr(lower=0, x=x, a=A, alpha=alpha, overwrite_a=False) #See https://github.com/scipy/scipy/issues/8155
      A[:] = At
      symmetrify(A, upper=True)
docs: Performs a symmetric rank-1 update operation:
      A <- A + alpha * np.dot(x,x.T)
  
      :param A: Symmetric NxN np.array
      :param x: Nx1 np.array
      :param alpha: scalar