[BUG] AssertionError sometimes raised in Nastran float -> string conversion

[whophil]

Describe the bug
AssertionError is sometimes raised in Nastran float -> string conversion

To Reproduce

from meshio.nastran._nastran import _float_to_nastran_string

f = -167.99725341796875 # a float that fails; originally it was the result of some upstream operation
_float_to_nastran_string(f)  # raises `AssertionError`

Diagnose
meshio=5.3.4

[adtzlr]

Yes, I encountered that too. This is related to afcdfe0. It happens because the negative sign produces a string which does not meet the requirements.

Possible Solution

Change the output precision from 11 to 10 to take the possible negative sign into account.

meshio/src/meshio/nastran/_nastran.py

Line 412 in 0138cc8

out = np.format_float_scientific(value, exp_digits=1, precision=11).replace(

or an "adaptive" solution as proposed in #1350.