How to extract envelope for piecewise defined function?

I have a plot generated from an ugly and complex set of piece-wise functions. I’m looking to extract the envelope function from this data set. I’ve tried a lot of suggestions in other threads, but none seem to contain information about dealing with piece-wise functions. I’ve tried using a Fourier series, but that didn’t seem to give me what I was looking for. The plot is located belowenter image description here

extract email from facebook group

FBCANDY is a Must Have tool For Any Professional Marketer.


Game Changer for people who are doing DropShipping/Ecommerce Shopify, Amazon, eBay and more.
FBCANDY is a Must Have tool For Any Professional Marketer .FBCANDY Helps you in many ways,Like

*FBCANDY collects and provides latest trending products including: Last week’s Best Seller, Today Best Seller, Just-launched Best Seller. Reveal daily LIVE revenue and sold number.

*Just-launched Trending provides list of latest released products which bring high revenue. These are the most potential profitable items you can easily sell when the competition is low.

*Millions of products found in seconds.Figure out your niche faster with powerful filters.

*From GOOGLE, It retrives all valid email addresses on any Website by Keywords. It automatically removes duplicates, and intelligently takes off false email addresses.

*You can Get targeted Email from facebook.

So why are you waiting for?? Keep calm and get it from here -FBCANDY>