# Problem with Metric Tensor coordinate change.

I define a M manifold with three charts, I then define a metric on one of the charts MH. I then want to see the metric components in one of the other charts BL. I have defined differential maps between the charts.

gMann(MH) works and I can display the components but,

gMann(BL) gives the error:

ValueError: the provided domain is not a subset of the field's domain

print(subdomain,self._restrictions) gives 'Open subset MBL of the 4-dimensional Lorentzian manifold M {}' .

How do I make this work please? I will post the code in comments below.

Link to code at my website. The problem surfaces in cell 6. The function definitions between cell two and six can be ignored.

http://alan.atstafford.co.uk/BlackHol...