test_mc01td_D failure on Windows

[roryyorke]

See attached build log. The failure is

======================================================================
FAIL: test_mc01td_D (test_mc.test_mc)
test_mc01td_D: test discrete option
----------------------------------------------------------------------
Traceback (most recent call last):
  File "c:\Users\rory\Documents\slycot\slycot\tests\test_mc.py", line 27, in test_mc01td_D
    self.assertEqual(stable, 1)
AssertionError: -1 != 1

----------------------------------------------------------------------

Build script:

set CONDA=%HOMEDRIVE%%HOMEPATH%\Miniconda3\condabin\conda.bat

echo %CONDA%

CALL %CONDA% --version
@if errorlevel 1 exit /b %ERRORLEVEL%

CALL %CONDA% activate base
@if errorlevel 1 exit /b %ERRORLEVEL%

CALL %CONDA% remove --yes --all --name build-slycot-py35
@if errorlevel 1 exit /b %ERRORLEVEL%

CALL %CONDA% create --quiet --yes --channel conda-forge --name build-slycot-py35 python=3.5 scikit-build flang numpy scipy
@if errorlevel 1 exit /b %ERRORLEVEL%

CALL %CONDA% activate build-slycot-py35
@if errorlevel 1 exit /b %ERRORLEVEL%

cd slycot
@if errorlevel 1 exit /b %ERRORLEVEL%

git describe --always --dirty
@if errorlevel 1 exit /b %ERRORLEVEL%

git status --ignored
@if errorlevel 1 exit /b %ERRORLEVEL%

@rem a hack; no f2py.exe
where f2py > %TMP%\F2PYPATH.txt
@if errorlevel 1 exit /b %ERRORLEVEL%
set /P F2PYPATH=< %TMP%\F2PYPATH.txt
@if errorlevel 1 exit /b %ERRORLEVEL%

python setup.py install -- -DF2PY_EXECUTABLE=%F2PYPATH%
@if errorlevel 1 exit /b %ERRORLEVEL%

cd slycot\tests
python -m unittest -v

build log: slycot-win-build.txt

[bnavigator]

Can you switch to pytest instead of old unittest?

[bnavigator]

Slycot/slycot/src/MC01TD.f

Lines 53 to 55 in ac53a0a

	C STABLE (output) LOGICAL
	C Contains the value .TRUE. if P(x) is stable and the value
	C .FALSE. otherwise (see also NUMERICAL ASPECTS).

Slycot/slycot/src/math.pyf

Line 8 in ac53a0a

logical intent(out) :: stable

Slycot/slycot/math.py

Lines 50 to 51 in ac53a0a

	stable : int
	Equal to 1 if P(x) if stable, 0 otherwise.

Slycot/slycot/math.py

Line 58 in ac53a0a

out = _wrapper.mc01td(dico,dp,p)

Slycot/slycot/tests/test_mc.py

Lines 14 to 32 in ac53a0a

	def test_mc01td(self):
	""" test_mc01td: doc example
	data from http://slicot.org/objects/software/shared/doc/MC01TD.html
	"""
	(dp, stable, nz) = mc01td('C', 4, [2, 0, 1, -1, 1])
	self.assertEqual(dp, 4)
	self.assertEqual(stable, 0)
	self.assertEqual(nz, 2)
	def test_mc01td_D(self):
	""" test_mc01td_D: test discrete option """
	(dp, stable, nz) = mc01td('D', 3, [1, 2, 3, 4])
	self.assertEqual(dp, 3)
	self.assertEqual(stable, 1)
	self.assertEqual(nz, 0)
	(dp, stable, nz) = mc01td('D', 3, [4, 3, 2, 1])
	self.assertEqual(dp, 3)
	self.assertEqual(stable, 0)
	self.assertEqual(nz, 3)

There is something wrong with the documented but nowhere defined mapping of logical to int. Does the Windows compiler map logical differently?

[bnavigator]

Some difference between (old) Intel compilers and gfortran: https://stackoverflow.com/questions/37293641/implicit-conversion-integer-logical-in-fortran-if-statement

[roryyorke]

If I comment out that assertion, the test passes.

We could check in slycot.math.mc01td for out[1] being non-zero, and make the output 0 or 1 (though I don't know if .FALSE. always maps to 0). Or we could change the Fortran function to output an integer 0 or 1, instead of logical type.

"armflang" has .TRUE. set to -1, according to docs from mid-2018 [1]. I couldn't find anything else about flang conventions, neither via Google, nor flang --help.

Are we using flang in any of the Travis CI builds?

[1] https://armkeil.blob.core.windows.net/developer/Files/downloads/hpc/Arm-Fortran-Compiler-Reference-guide/Arm_Fortran_Compiler_Reference_101380_1840_00_en.pdf

[bnavigator]

I am already working on a PR. Stand by.