IMUGPSFusionTest error

[wangminhang]

when i run "rosrun roamfree IMUGPSFusionTest " with your data, it output error "[FactorGraphFilter] Error: Not enough vertices provided for 'Accelerometer', which is of order 2",why? how to fix it?
thank you.

[DavideACucci]

Dear @wangminhang, I am looking at this right now.