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Description

When exporting a gdml, the matrix values are set with the default C++ ostream precision (6 significant digits) and not with the fFltPrecision. This is often not enough precision. (e.g. it fails to compute the correct group velocity in geant4 for me if it's just 6 significant digits).

Reproducer

Use TGeoManager::Export with a matrix saved in the TGeoManager

ROOT version

all

Installation method

all

Operating system

all

Additional context

No response