Add model corfficients to export

[knorthover]

🚀 Feature Request

Add the fitted model coefficients to the data export. Also an option to show the coefficients, especially for trend lines, would be useful.

🔈 Motivation

This is a great package and really easy to use to get quick answers to questions business users ask; particularly about the impact of deploying new features to our website, etc. Because these tend to be relatively short time assessments (months) the trends are usually simple straight lines. Prophet is useful because our business has strong weekly variation and it handles that with minimum effort. Being able to get the trend slopes directly would be a great help!

🛰 Alternatives

Currently I do this by reading dates and values off the trend line tooltip.

📎 Additional context

It seems to be a common Prophet question and they've recently updated the package https://githubmemory.com/repo/facebook/prophet/issues/1972

[github-actions]

Hello @knorthover, thank you for your interest in our work!

If this is a bug report, please provide screenshots and minimum viable code to reproduce your issue, otherwise we can not help you.

[MaximeLutel]

Hi @knorthover, thanks a lot for the feedback, I will add it to the backlog!