I would like to understand better the output strike_dir
from PyLith. This output is found on the files fault_info.h5 for example.
In the PyLith manual it says that strike_dir
is the “Direction of fault strike in global coordinate system”.
In the example below I show a fault plane that is perpendicular to the xdirection. The field strike_dir
that is output from PyLith contains 3 components. I am trying to wrap my mind about this information:

The output from
strike_dir
are in radians, correct? 
In the figure below, why is the xcomponent of the
strike_dir
output equal to 0.17? Assuming that this is radians, this would correspond to 9 degrees. Shouldn’t it be 90 degrees ? 
The ycomponents is equal zero, which make sense in this case, right?

Why is the zcomponent equal to 0.98, which in is ~56 degrees?
Thank you in advance for the help.
Josimar