ELLIPSE should accept an axis ratio as small as 1e-10

[mozman]

Discussed in #799

^{Originally posted by dmkh1984 December 15, 2022}
Good day.
I open document (try DXF2018 and DXF2010/2013 formats, works same), delete some entities with paperspace.delete_entity(entity) and try to save document with doc.save() and got broken file and this:
`Traceback (most recent call last):
File "F:\Scipts\Delete\Delete.py", line 35, in
doc.save()
File "C:\Users\PyDev\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\ezdxf\document.py", line 543, in save
self.write(fp, fmt=fmt) # type: ignore
File "C:\Users\PyDev\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\ezdxf\document.py", line 601, in write
self.export_sections(tagwriter)
File "C:\Users\PyDev\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\ezdxf\document.py", line 620, in export_sections
self.entities.export_dxf(tagwriter)
File "C:\Users\PyDev\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\ezdxf\sections\entities.py", line 111, in export_dxf
layouts.modelspace().entity_space.export_dxf(tagwriter)
File "C:\Users\PyDev\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\ezdxf\entitydb.py", line 391, in export_dxf
entity.export_dxf(tagwriter)
File "C:\Users\PyDev\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\ezdxf\entities\dxfentity.py", line 686, in export_dxf
self.export_entity(tagwriter)
File "C:\Users\PyDev\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\site-packages\ezdxf\entities\ellipse.py", line 126, in export_entity
assert is_valid_ratio(self.dxf.ratio)

AssertionError`

Overall, great package, big thanks.

[mozman]

I did some tests with DWG Trueview 2021 and the valid range for the axis-ratio also expands into the negative side and the lower limit of 1e-10 is also new to me: -1.0 ... -1e-10 and +1e-10 ... +1.0

EDIT: the valid negative range is also documented in my source code 😄

[mozman]

@dmkh1984 I'm not sure if this is really the solution, so the sample file would still be appreciated.

[dmkh1984]

Fun fact, after I delete all "sensitive" info, it works just fine. So, it seems that it got corrupted object. I will try to find this obj on
weekend and send file just with them.

[mozman]

@dmkh1984 The problem is clearly the ratio attribute of the ELLIPSE entity. I only need this value and this script can save you some time:

import ezdxf

doc = ezdxf.readfile("your.dxf")
for e in doc.entitydb.values():
    if e.dxftype() == "ELLIPSE":
        print(f"Ellipse axis-ratio: {e.dxf.ratio}")

Please post the output of this script here.

[dmkh1984]

I slightly update script:

import ezdxf

doc = ezdxf.readfile("Delete_Target.dxf")
print("Work start")
for e in doc.entitydb.values():
    if e.dxftype() == "ELLIPSE":
        print(f"Ellipse #{e} axis-ratio: {e.dxf.ratio}")
print("Work end")

That I get it's a lot, so I save output to file (attached)
Output.txt

[mozman]

Thank you - it was really the lower bound of 1e-6 for the axis-ratio which caused the issue and this is fixed now.