I decided to fix the bug I reported. optimize.line_search now calculates gfk before using it in the computation of derphi0, and the documentation has been amended.
Ticket #1726: Removed (can be None) from the docs on myfprime. Refer …
Ticket #1726: Computed gfk before using it in calculations.
Getting my thanks on.
Thanks. Merged in 8651e2e...b760f72.