numpy 1.12.0 IndexError

[neok]

cannot build fenics 2016.2.0 with numpy 1.12.0

in ffc/tensor/tensorreordering.py,

indexing with a float raises IndexError:

if restrictions[i] == "+":
    position = position + [slice(0, dim / 2)]
elif restrictions[i] == "-":
    position = position + [slice(dim / 2, dim)]
else:
    position = position + [slice(0, dim)]

[Jan Blechta]

Could you provide a way how to reproduce the problem?

[Miklós Homolya]

dim / 2 gives a float with Python 3 division.

[Jan Blechta]

Right, so should be dim // 2 and optimally we should have from __future__ import division.

[neok]

It is due to a change in numpy's api:

github.com/numpy/numpy/blob/master/doc/release/1.12.0-notes.rst

-- 
-- Generating form files in demo, test and bench directories. May take some time...
-- ----------------------------------------------------------------------------------------
CMake Error at CMakeLists.txt:921 (message):
  Generation of form files failed:

  Compiling 1 forms in demo/undocumented/block-matrix/cpp...

  ffc -l dolfin -s -O -r auto StiffnessMatrix.ufl

  [...]

  Compiling 2 forms in demo/undocumented/extrapolation/cpp...

  ffc -l dolfin -s -O -r auto P2.ufl

  ffc -l dolfin -s -O -r auto P1.ufl

  Compiling 1 forms in demo/undocumented/auto-adaptive-navier-stokes/cpp...

  ffc -l dolfin -s -O -r auto -e AdaptiveNavierStokes.ufl

  Traceback (most recent call last):

    File "<...>/cmake/scripts/generate-form-files.py", line 92, in <module>
      ret = ffc.main(args)
    File "<...>lib/python3.6/site-packages/ffc/__main__.py", line 234, in main
      code_h, code_c = compile_ufl_data(ufd, prefix, parameters)
    File "<...>lib/python3.6/site-packages/ffc/__main__.py", line 90, in compile_ufl_data
      parameters)
    File "<...>lib/python3.6/site-packages/ffc/errorcontrol/errorcontrol.py", line 86, in compile_with_error_control
      code_h, code_c = compile_form(ec_forms + forms, object_names, prefix, parameters)
    File "<...>lib/python3.6/site-packages/ffc/compiler.py", line 141, in compile_form
      prefix, parameters, jit)
    File "<...>lib/python3.6/site-packages/ffc/compiler.py", line 188, in compile_ufl_objects
      ir = compute_ir(analysis, prefix, parameters, jit)
    File "<...>lib/python3.6/site-packages/ffc/representation.py", line 187, in compute_ir
      for (form_id, fd) in enumerate(form_datas)]
    File "<...>lib/python3.6/site-packages/ffc/representation.py", line 187, in <listcomp>
      for (form_id, fd) in enumerate(form_datas)]
    File "<...>lib/python3.6/site-packages/ffc/representation.py", line 450, in _compute_integral_ir
      parameters)
    File "<...>lib/python3.6/site-packages/ffc/tensor/tensorrepresentation.py", line 91, in compute_integral_ir
      reorder_entries(terms[i][j])
    File "<...>lib/python3.6/site-packages/ffc/tensor/tensorreordering.py", line 59, in reorder_entries
      tensor[position] = A0.A0

  TypeError: slice indices must be integers or None or have an __index__
  method

[Martin Sandve Alnæs]

This was fixed in c8ef816ed45336d5fd7e9689c40cb1150d71d71f