Grouped Interpolate

[#1]

While writing the post
https://community.jmp.com/t5/Discussions/Difference-of-lines/m-p/691643/highlight/true#M87740 

I was reminded of a question that a colleague of mine had some while ago:

Is there a grouped Interpolate function in JSL?

Interpolate(myheight, :height, :weight, by(:sex), for({"F","M"}))

which returns {weightF, weightM} @ myheight for F & M after separately interpolating :weight vs. :height for the 2 subgroups?

[#2]

I think when I did this, I did write my own function(s).

I'm fairly sure I have seen some wish list items regarding using by/group with matrix operations. This is the Matrix Operations with By variables 

[#3]

here is a wish to add a GroupBy option to Interpolate:

Group by - sooo useful!!! how about Interpolate?