Extending trend lines (`tlines`)

[sumprain]

Hello Daniel,

Thanks a lot for such a useful package.

I have made an enhancement in the trend line construction (using tlines kwarg in plot function).

By adding kwargs extend_start and extend_end to tlines parameter, we can extend trend line by extend_start dates from the start date and extend_end dates from end date.

Regards

@sumprain

[DanielGoldfarb]

@sumprain Suman- Thank you so much for contributing to mplfinance. This enhancement looks interesting and useful. I will try to make time this week to code review and test, to be able to merge and release.

In the meantime, would you be willing to please add one or two use-case examples to the very end of the using lines tutorial. That will be very helpful.

As long as this Pull Request continues to be open, any changes you push to sumprain:master will automatically be propagated from sumprain:master into this Pull Request.

All the best. --Daniel

[sumprain]

Thanks a lot @DanielGoldfarb . I will surely do the needful.

Regards.

[sumprain]

While preparing examples, I detected some anomaly in slope of trend line when show-nontrading days is false. I am correcting it and will pull request it. Thanks and Regards @sumprain

[sumprain]

Dear Daniel, I have corrected the anomalies and added use cases in using lines tutorials.

Thanks and Regards

@sumprain