Add threshold index output on interpolate 1D array function when the 1D array input is an array of points.

[viScience]

The interpolate 1D array function has a powerful but under appreciated feature of being able to do segmented linear interpolation when the array input is an array of points.  (For example in an array of PID profile setpoints).  The interpolate function will directly produce the correct interpolated y value for any 'segment' in the array which is very cool.  However it does not expose the threshold index which would be very useful and is most certainly already computed internally.  In the use case of traversing an array of PID profile setpoints, it would be good to know what segment is being interpolated at any given time.

[wiebe@CARYA]

Doesn't a Round Toward -Infinity give you that?

A Q&R with 1 gives you the index and fraction.

It seems to be very little effort to get what you're asking for.

Adding the index will change the connector pane and might break things. Maybe not, but given the gain why risk it?

[viScience]

I am talking about the case where the Interpolate 1D array is receiving an array of points.

This is a test case to illustrate what I am referring to.  

[crossrulz]

The solution could be the output is a cluster containing the calculated X and Y values. I'm not sure if that would be helpful or cause more confusion.

[viScience]

Still I would like some appreciation of the original suggestion which is for the case where the 1D Interpolation is being used to perform segmented linear interpolation (which in itself is certainly not well known) it would be nice if there was a 'segment' or array index output since it is already being computed internally and is not as trivial as you indicated to compute externally.

[wiebe@CARYA]

I think the function has some of that magic, but the description is wierd and it's very tricky.

So the function interpolates on the Y values, and returns the interpolated X value.

Of course you could argue that you now want the index returned. And that's fair 🤗.