v0.11.3

ControlSystems v0.11.3

Diff since v0.11.2

Closed issues:

• similarity_transform(sys, T) throws an error when transformation matrix T is complex (#462)
• LFT doesn't give results as in K. Zhou, J. Doyle (#577)

Merged pull requests:

• add relative gain array (#576) (@baggepinnen)
• bugfix for lft, issue #577 (#578) (@olof3)
• handle layout=1 in bode without subplot spec (#579) (@baggepinnen)