Convenience function for returning a 1 dimensional ndarray of values
from X, layers[k], or obs.
Made for convenience, not performance.
Intentionally permissive about arguments, for easy iterative use.
- Parameters:
 
- k 
str Key to use. Should be in var_names or obs.columns.
 
- layer 
str | None (default: None) What layer values should be returned from. If None, X is used.
 
 
- Return type:
 
ndarray
 
- Returns:
 
A one dimensional ndarray, with values for each obs in the same order
as obs_names.