# Revision history [back]

The issue arises because the transition map from chart Y to chart X_U has not been defined. You must implement it as follows, just after the definition of transit_Y_to_X:

transit_Y_to_X.set_inverse(t, atan2(y, x) - Omega*t, atan2(z, sqrt(x^2+y^2)), sqrt(x^2+y^2+z^2),
verbose=True)
transit_Y_to_X.inverse().display()


Then the display of the connection coefficients w.r.t. Y.frame() is OK (albeit quite slow: while investing your issue, I've discovered that the computation efficiency can be significantly improved; I'll open a ticket for this).

The issue arises because the transition map from chart Y to chart X_U has not been defined. You must implement it as follows, just after the definition of transit_Y_to_X:

transit_Y_to_X.set_inverse(t, atan2(y, x) - Omega*t, atan2(z, sqrt(x^2+y^2)), sqrt(x^2+y^2+z^2),
verbose=True)
transit_Y_to_X.inverse().display()


Then the display of the connection coefficients w.r.t. Y.frame() is OK (albeit works, albeit quite slow: slow (*).

(*) while investing your issue, I've discovered that the computation efficiency can be significantly improved; I'll open a ticket for this).improved by reordering some loops; this is now Trac #28543.