1. 15 Dec, 2017 2 commits
    • Dániel Varjas's avatar
      fix bug in phs_symmetrization using square root method · 79800648
      Dániel Varjas authored
      This commit fixes the bug in phs_symmetrization when it fails to produce ph eigenstates
      with PH^2 = +1 when one of the wave functions is mapped exactly onto another one by PH,
      as in this case the PH symmetrized wf's from the two are identical. This is the case
      with wfs = np.eye(2) and  particle_hole = sigma[1], the second vector returned is an
      eigenstate with eigenvalue -1 not +1. In general this can be even worse, if there are
      multiple such vector pairs some vectors may not be ph eigenstates at all.
      
      The new code uses an improved version of the matrix square root method from
      Applied Mathematics and Computation 234 (2014) 380-384.
      
      Tests are modified to clear up the random unitary generation process (using kwant.rmt).
      Tests are now guaranteed to feed orthonormal set of vectors to phs_symmetrization().
      Add extra tests for the fully off-diagonal case where the old method fails.
      79800648
    • Christoph Groth's avatar
      select matplotlib backend only when needed · 8ca980f7
      Christoph Groth authored
      Previously, in order to not to fix the matplotlib backend, we required
      users to import matplotlib.pyplot before calling any Kwant plotting
      functions.  This did not have the desired effect, since we did import
      `matplotlib.backends` and that also fixes the backend.
      
      Now, both backends and pyplot are imported at the last possible moment
      and a warning is emitted if this fixes the backend.
      8ca980f7
  2. 13 Dec, 2017 2 commits
  3. 08 Dec, 2017 13 commits
  4. 07 Dec, 2017 1 commit
    • Joseph Weston's avatar
      remove dubious resize of transformations when plotting in 3D · 6647bc7a
      Joseph Weston authored
      Previously, when plotting a 3D system with 'site_size' provided
      explicity as a sequence, a ValueError would be raised when using
      '%matplotlib inline' or '%matplotlib notebook' from a Jupyter
      notebook. We do not add a test for this, because that would require
      depending on Jupyter.
      
      Closes #39.
      6647bc7a
  5. 05 Dec, 2017 1 commit
  6. 04 Dec, 2017 5 commits
  7. 30 Nov, 2017 9 commits
  8. 27 Oct, 2017 1 commit
  9. 26 Oct, 2017 3 commits
  10. 13 Oct, 2017 1 commit
  11. 14 Sep, 2017 2 commits