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thermo_add.py crashes with NumPy 2.x and OpenMDAO 3.42+ #116
Description
ThermoAdd.compute() raises a TypeError at line 121 due to two breaking changes:
-
OpenMDAO 3.42.0 stores scalar inputs as
(1,)arrays instead of scalars -
NumPy 2.0 removed implicit
float()conversion on 1-element arrays
The crash: W_other_out[self.idx_compo] += W_other_mix on line 121 causes the following TypeErrors:
TypeError: 'DESIGN.burner.mix_fuel.thermo_add' <class ThermoAdd>: Error calling compute(), only 0-dimensional arrays can be converted to Python scalars
File "C:\Users\REDACTED_FILEPATH\pycycle\thermo\tabular\thermo_add.py", line 121, in compute
W_other_out[self.idx_compo] += float(W_other_mix)
^^^^^^^^^^^^^^^^^^
TypeError: only 0-dimensional arrays can be converted to Python scalars
Fix: change line 121 in thermo_add.py to W_other_out[self.idx_compo] += W_other_mix.item()
Versions: om-pycycle 4.4.0, openmdao 3.42.0, numpy 2.4.2
Activity
Updated thermo_add.py line 121 to be compatible with OpenMDAO 3.42.0 …
stefano2734 commentedon Mar 11, 2026
New releases Numpy 2.4.3 and openMDao 2.4.3
Should be Equal or perhaps more to do here?
Jhawk414 commentedon Mar 12, 2026
I'm not sure I understand your question.
However, OpenMDAO release 3.43.0 was released today (11 March 2026) and I haven't had a chance to see if this issue is affected.
Add hangar-pyc: pyCycle gas turbine cycle analysis MCP server
stefano2734 commentedon Apr 30, 2026
Sometimes new version errors are solved in next version. NumPy 2.44 is also now available.
And sometimes a permanent change is the source of failure.
flight-test-engineering commentedon May 7, 2026
@Jhawk414 , are you going to open a PR with your fix?
Jhawk414 commentedon May 13, 2026
Yep. As shown I've created PR #117 to address this. One line fix
Updated thermo_add.py line 121 to be compatible with OpenMDAO 3.42.0 …